my home energy. co.uk

I have little control over the content of these google adds
and so if you click on them and it is of benefit to you, then
good, if not well you have at least supported my web site,
for which I thank you


Welcome to my home energy                  last update25-02-2008

I suppose I should mention at the start, my wife tells me that I have a tendency to ramble on a bit! but if you've got an hour to spare and a note pad and pencil, hopefully you'll glean a few ideas from the so called ramblings of a now retired, 35 years in the business chap, but feel free to use my short cuts to that which might interest you most, such as :- 

  payback    saving it   making it   swimming pool   grumbles    high rise flats    the car    contact  

Oh no, not someone else telling me I'm damaging the planet. Well,, yes, but I think you'll find this site differs from most, if you are interested in saving energy, for whatever reason then read on and judge for yourself

swimming enjoyment even in the coldest weathersummertime enjoyment

our pool cabin, completed May 2003

Be very aware, there is a large portion of the industry which misuses terminologies such as "eco" "green" "environmentally freindly" "carbon neutral" etc, whilst making huge profits at the expense of both the environment and the end users.

Misguided silliness abounds, we are in desperate need of a reality check

for lower carbon emmisions, higher returns and lower reliance on central heating, choose high thermal value insulation, it needs no maintenance and will possibly be around for generations to come

How effective are so called green products ?

My intentions...

An alternative and what I believe to be an honest view of some of the so called green products and methods which are available today and deal with a very serious subject, that of the reduction of energy use from fossil fuels, my intention is to promote thought and discussion and to question just how effective are so called green products ?. Plus, do swimming pools have to be so damaging to the environment?  and whilst I am now retired, having had many years experience in this subject of reducing energy reliance, my knowledge of web pages and the like is minimal so please bear with me, whilst I create the material content.

I might add at this point, that this U.K. energy saving information site which I started to develope at the back end of 2006, is not for profit and the information provided is purely here to promote further thought on what is quite a complex subject

Oh no, not another energy efficiency site !   With such a vast amount of existing and readily available information on this subject, you may be wondering what I could possibly add, well it's because of my 30 or more years of experience, having been involved for most of that time in the design, development and installation of many of these so called green products and systems, I know a lot about a little, but more importantly I know a little about a lot. and want to offer my opinions on this very broad subject, whilst you may not accept all that I have to say, and lets face it, there are many differing views, at the very least I will have achieved my aim if it causes you to become more interested in the things that you can achieve, but at the same time to question more closely some of the claims made in the media or sales blurbs and /or make a more informed choice, wouldn't it be lovely if a green product actually exceeded its suggested performance. All this said, you will see that I am firmly committed to green issues, saving energy is a very worthy challenge and can become quite an addictive and enjoyable hobby.
There already exists many sites loaded with information on commercially available products, and so I want to concentrate on my past experiences surrounding some of these products, also things that can be achieved by the adventurous and not so adventurous.

If my home energy saving from simple ideas through to complex systems, DIY and sometimes quirky attempts at saving energy inspire you then my time spent adding this material has been very worthwhile.

My view point

Lobby,  yes, worry about the doom and gloom,  no, just do your bit for you !

No matter whether it is the human race at fault or natural causes or both, climate change is firmly in the grip of acceleration and it is extremely doubtful that if all the developed and developing nations working together (a highly unlikely scenario) could do anything other than slow it down. Like it or not, each and everyone of us in this modern society continue to damage the environment and so, with very little help from government, looking for ways to maximize the efficiency of our energy use and to reduce our reliance or move away from fossil fuel is possibly the best we would want to achieve, at the very least it provides us with a feel good factor. Problem is I suppose some would argue that the resultant reduced energy costs, provides us with greater purchasing power on even more environmentally unfriendly products or activities.

There is talk of radical human measures to change the course of nature, climate, the world!, I suppose we humans believe we can do anything, we are certainly very good at destroying our own environment.

My driving force through the years is two fold, one I can't stand waste in any form and two, I have never been a high earner and so by saving on energy has allowed my small amount of money to go further. If we all used energy wisely, and I definitely don't mean denying oneself of comfort or pleasure, then maybe this would lead to some reduction in the damage to our environment, some experts tell us it may even influence climate change

some of the bigger issues which are of major concern to me:-

"apathy still apparent"

It is  my firm belief that there are many missed opportunities for our government to influence major changes, for instance we are still today, building houses with insufficient thermal standards and as a consequence are providing these houses with conventional central heating systems which gobble up valuable energy at an alarming rate, with modern insulating materials,  it is possible to maintain comfort temperatures without the need of the conventional central heating system.

high rise flats

which local authority will be first to recognise this valuable asset before it's too late:-

another majestic block of flats shortly to be demolished, gone foreverand more sad destruction, there must be a better wayMy vision for these is private sector, low cost, very low energy homes, complete with all necessary security systems

these flats, just an example of many due for demolition, are but a one minute walk away from some recently built flats, oops pardon me, apartments costing in excess of £150,000  each, It is questionable as to whether modern day build practice is any better than that used in the sixties certainly there was very solid construction methods/ materials applied to many of these high rise flats. See my thoughts below on how these flats could be turned into very desirable, very low energy homes at a fraction of the cost of demolishing and building new homes.

what are the two main differences between the 60,s high rise flats and present day flats, answer :- insulation and 40 odd years

Why blow up 1,000,s of  perfectly good homes and yet at the same time we are in desperate need of many more homes :-

Many of our local councils are demolishing blocks of flats, quite often 80 to 100 homes at a time simply because they are not "fashionable", and, yes there are social issues but these will continue to exist anyway and it is not necessarily the method of housing which is at fault. If these flats are structurally sound, they could be given double glazing, external insulation, new services, a face lift inside and out and could become  much needed, private sector, low cost and very low energy homes and could even boast to be carbon neutral (on the basis they are already built) could even support very easily a car pooling scheme where the flat owners pay a rental for shared use of vehicles, with just one main entrance to all these flats, the cars would just sit there and be  available for use, I would think it is close to ideal for this sort of scheme. Areas within the existing structure could be rearranged to include secure areas, covered parking, office space for those who can "work from home", gym, recycle shoots/collection areas, etc. 

Reading the web, I see that one of the main grumbles from tenants of these high rise flats was the cold conditions and mold growth on the walls, both problems can be easily overcome with modern day insulation materials

With very little external surfaces (approx 1/5 of a detached dwelling) in relation to internal surfaces and  the right amount of external insulation, it is possible that with the vast amount of encapsulated concrete structure acting as a massive stabilized heat store, these flats would need virtually no central heating, simply solar gain, the activity levels and body heat could maintain comfort levels. The roof is ideal for creating a rain water catchment area which could serve at the very least irrigation of the landscaped gardens if not all the W.C's throughout the block and if there is any merit in locally placed wind turbines then, again, the roof of a block of flats I would have thought ideal for this purpose, with uninterrupted access to any available wind. 

My thoughts may be too *far reaching at this point, but it is also very possible and with present day technology that the pool cars whilst not being driven could serve both the hot water demands of these flats and provide base load electrical energy see my article on cars below. 

*far reaching, my thoughts may be, but I truly believe that the large organizations and governments who can make these big changes are apathetic, although, yes they talk a lot and put out lots of paperwork, I suppose it sounds and looks good!.

It really is sad in this so called enlightened age, to see this destruction. I don't think that I can test my theory, not enough cash available, but maybe there's a brave multi millionaire who would want to give it a go, just think of the kudos not to mention the profit if this transformation were to be successful. Most architects are capable of creating a new building, my admiration goes out to the architect who can successfully transform existing structures giving them a new lease of life. At such a high cost to the environment to demolish these flats, I would have thought that any local authority would be only too pleased for an alternative answer.

Whichever local authority is first to take up this opportunity is of no matter to me, but bring it on soon, before we loose 1,000's more of these valuable homes 

the car

The car needs to be more environmentally friendly ??, I feel a sense of naivety coming on, believing that car manufacturers would follow any coarse other than that which will maximize their short term profit

Public transport, yes it is necessary, but it will never replace individual transport, well not unless the latter is banned, or until public transport is made available at any time and up every street. So the car in what ever form  is here to stay, it maybe that eventually we will all be driving around in electric vehicles with the energy source either being provided from a new style battery, hydrogen fed fuel cells or solar, but for now, what if the car was of dual purpose, that of getting from A to B and when it would normally be idle    (which is 90% of the time) used for heating the home and supplying electricity to the home, this is a real possibility and in fact the principle has been around for many years in the form of combined heat and power units (chp). Having been involved over the years in both sale and servicing of these chp units, I have often expressed this view point. All that is needed is for the two technologies to be brought together. Ideally the petrol engine should be modified to operate on some form of bio fuel but again this is in the pipeline so to speak. Maybe environmentalists wouldn't then react so aggressively towards this sort of transport.

From my experience, the car engine even in it's simplest form, when used to drive a CHP unit has a life expectancy of over 10,000 hours and comparing this with a car traveling at an average speed of just 30 mile per hour this equates to a staggering  300,000 miles, even a small car engine with an input of 53 KW has the capacity to output over it's lifetime 380,000 KWhr ( over £7,000 worth* ) of heat and 150,000 KWhr ( over £13,000 worth* ) of electrical power. It is worth noting that whatever the engine is used for, the input/output percentages of a conventional car engine  are very similar just a mere 30% actual driving force and a massive 70% heat output, so just consider how much energy is being wasted in the form of heat as we drive around even in small cars.
Docking stations within the home are technically possible, and could be built into new homes or retrofitted to existing housing stock, these would allow the transfer of the electrical output and the generated heat from the car directly into the home systems, could even be applied to work places, where again, the car is normally idle for hours at a time
* present day electrical and gas costs  


Over 90% of our so called rubbish is recyclable, and yet most councils provide us with silly little green boxes allowing 10% or less capacity and in some instances these are collected just once per fortnight, I have thoughts on this, see grumbles


There are so many doom mongers these days, telling us of impending disasters, land masses disappearing under swollen seas, excessive land heat levels etc etc, and of course there is a possibility that they might eventually be proved right, it is little wonder therefore that there are lots of people left wondering if there is any point trying to do their bit, well the answer to that is :-a resounding YES : forget the big issues, concentrate on what you can do for you and if this helps with the larger picture then good, if not, you've at least saved yourself some money and may also have made your home more comfortable

Apart from lobbying, maybe we should leave the big issues to those who are influential and that can make a difference, my main aim is to concentrate things that we as individuals can do to save energy:-

We can make our existing homes more energy efficient

Most of us live in existing housing stock, we can't afford, don't want to, or haven't the opportunity to build our own, and have to make do with the typically extremely poor energy performance, however there are many ways in which we can reduce our reliance on energy, my 1960's house for instance, a typical detached 3 bed used to consume for it's heating and hot water, 29,000 KWhr per year and today, consumes just *17,000 KWhr* per year, I continue to strive to improve on these figures, it is a worthy challenge and one that I really enjoy. Read on and see the various things that I have done, some very simple measures and some, not so simple.

* I have just checked the latest gas consumption figures for my house, July to July 2007 ,and even though my house is now left with a legacy of a poorly installed cavity fill, the gas consumption now stands at just 13,700 KWhr per year, less than half that of previous years and this is definitely not at the expense of comfort - happy or what!


My grumble(one of many, it's my age you know!)

Anyone responsibly improving their property and in so doing, helping the government to improve its overall carbon emissions target are, by the very same government, being penalized for these improvements by way of local taxation. and VAT on energy saving products. This is not fair and is contrary to the government's verbal diarrhea regarding carbon reduction incentives. If the government were serious on this subject, there are many ways in which they could encourage us folk to do more, it is little wonder that most of us just selfishly look after our own little worlds. 


the world at present wastes enormous amounts of energy and so I strongly believe that it is futile in this country, to save energy at the expense of a good cuppa!

Looking around, I see actual wasted energy almost everywhere, I therefore have no intention of saving energy by denying myself of comfort or pleasures. I am definitely not for 'turning back the clock' but embracing all that modern living standards offer, enjoying the lot or at least that which I can afford, but at the same time considering ways of reducing my impact on the worlds resources by trying to achieve closest to optimum energy efficiency

I therefore make no apology for my enclosed swimming pool illustrated and would suggest that any so called Eco warriors or those of you who believe that we should all live in little mud huts to save the environment, should maybe leave now.
I actually believe that if all modern living standards and commercialism were withdrawn and each and everyone of us had to live off the land, this would still do little but to slow down climate change, but this shouldn't sway us from helping ourselves to save energy
I should make it clear at this point, that if I showed any signs of straying onto the Eco path my wife would possibly divorce me, no probs with me saving money, even the environment, but if the water doesn't flow or the lights don't come on, just maybe she would be a little upset! Comfort in other words is top priority, particularly at our age. I will mention later in some detail, the swimming pool. The building enclosing the pool may be of particular interest because, had it  been built for residential purposes, it would have been possible to run it at comfort levels, without the need of central heating, imagine not having to purchase a central heating system let alone having to suffer the running costs and all this down to high insulation standards. Even as this pool building is, operating all year at 30 deg C  for the pool requirements, the fabric losses even at 0 deg C outside are less than 2.5 KW per hour, the gas boiler that serves the whole building including heating the pool water which incidentally has no pool cover (our life style choice), and coping with the hot water to the showers, together with 24 hour ventilation to the pool hall is just 3 KW output, yes this is not a typing error, just 3 KW output. to put this into perspective, your typical house boiler is approx 10 KW output

home energy saving from simple ideas through to complex systems, swimming pool energy management, how effective are so called green products ?


You have spent time searching the net for saving energy or swimming pools info and found me, as I will be some time introducing all the material content maybe you would like to click this into your favorites and come back to me later, it's just possible that you will glean something from my experiences

contact :-

odbob@myhomeenergy.co.uk    ( please copy and paste this address into your favourite email sender)

Please note, at present I can only recieve calls on the contact detail, I cannot answer calls. But if there is any particular aspect that you would like me to cover, then, if I have the knowledge, I will add this information to the content.  If you want  a reply then please E-mail me :- alternative-energy@tiscali.co.uk

back to top


My home energy.co.uk

   home   saving it   making it   swimming pool   figures   grumbles


I use the words, pay back period, many times when referring to a green product and so an explanation of the way in which I use the term "payback" and "green product" may be appropriate

simply put, "payback" period refers to the amount of time in years that the product would have to perform in order to repay the original investment, usually this is  shown in monetary terms, however the more important consideration is that of environmental benefit, I will explain. All  production processes obviously cause environmental damage, green products are no exception to this and so the production of the green product, its support ware, integration equipment and installation materials together with all necessary transportation and maintenance materials all damage the environment. This damage, if the product is to be deemed worthy should be re payed well within the expected service life of the product, or at the very least, its supporting infrastructure, if this fails then the whole exercise would in my opinion be worthless, and  worst still, the net result actually damaging to the environment.

The labour element is not so damaging and therefore the monetary payback calculation should take into account how labour intensive a particular project is. I refer back in time to a Customer of mine who would always insist on manual workers to dig trenches by pick and shovel rather than to use mechanical diggers, I don't want to get embroiled in discussions regarding the reasons for this but it is a particular example of  where labour costs can become excessive and it would be unfair to include these costs when considering the environmental payback of a green product. In fact, had mechanical diggers been employed then this element would definitely be a contributory factor in damaging the environment

My definition of payback, it is the period in which a product will repay the damage caused to the environment by the production processes and transportation of both the product and all of it's associated wares

With purely "green products", it should be mandatory that the manufacturer provides an environmental profile of both the manufacturing deficit and the expected lifetime benefit, so that it is made absolutely clear as to the product's actual contribution to carbon reduction. I am certainly not convinced that all so called "green" products are good for the environment

Unfortunately environmental damage figures are not readily available to ourselves and so monetary payback whilst not very accurate at least provides some understanding of the situation. It also helps to sort out many of the over priced scams. I might add at this point that there are those of us who want to "save the world"and those of us who just want to save money, which ever category, it is important to have knowledge of and to consider the project's estimated payback period. 

I asked "what do you think of your solar panels"  "oh they're great"  "so what energy or money do they save you"   "oh I don't know but they must be doing a good job, the salesman said they will"

I categorize "green products" as those having no other purpose other than to "save the planet", they are not necessarily pretty and are quite often a pain for various reasons, the pay back period or more importantly recovering the debit to the environment is of paramount importance, these products, when employed on grid and services connected properties, include wind, water and solar power together with rain water collection systems, air to air plate heat exchangers etc. 

It should be noted that when wind, water and solar systems etc are employed to provide the only available power or resource, whether this is because the grid or services are not available in the area, or under circumstances where emergency cover is necessary, then they are not classified as green products for the purposes of payback.

in my opinion no other product comes close to that of insulation, it just sits there saving money

Payback is not so important on other products with dual or multi purpose roles, these can still repay some or all of their debit to the environment whilst contributing to our needs, comfort or pleasure and  these products include insulation, double glazing, controlled ventilation etc.

back to top


My home energy.co.uk

     home   payback   making it   swimming pool   grumbles  figures   

condensing boiler   rain water collection simple solutions   insulation   draught exclusion   ventilation   storage 

electric fire

saving it

whatever method or fuel is used to produce energy, saving it is of paramount importance. Use it, make it work for you, but don't waste it. saving it is the most rewarding and least complicated activity, whether you wish to simply save money or  the environment

simple solutions

"Turn off when not in use" :-

there are many ways to achieve savings some are very easily adopted, these include switching off lights when not required, turning off the standby feature on televisions, radios, computers and the like, however I have heard claims of up to £27 per year savings by just turning off the television, certainly with my television this is simply not true. Looking in the manual the standby consumption is rated as 0.6 watts, this , if the television was left on standby for a whole year would only consume 5300 watts (5.3 KWhr) at 10 pence per KW/hr this equates to a mere 60 pence per year saving, I'm not saying don't turn off the standby (every little helps), but just be aware that there are many exagerated claims of what is achievable in the way of savings.

power of the appliance in watts is the amount of power the appliance would consume in one hour of operation, there are 8760 hours in one year, and so as an example :-

standby power of say 1.5 watts x 8760 hours = 13,140 watts or divided by 1000 = 13.140 KWhr @  10 pence per KW hour used = £1.32 per year

You can determine savings by referring to the specific product manual, usually it will show the rating of standby and operating modes, my particular computer set up for instance, including the monitor, printer etc consumes 18 watts in standby mode and so this consumption if left on standby for a whole year works out to 160 KWhr and at 10 pence/KWhrt = £16 / year I therefore do switch this off when I have finished for the day in fact I installed a socket outlet to the rear of the desk so that I can easily switch off everything.

There a number of items that cannot be turned off for various reasons, fridge, freezer, burglar alarm, door bell, answer phone, clocks all of these consume electricity, my fax machine however, now that I am retired, I do turn off because it has a standby load of 8 watts which equates to approx £7 per year cost, mind you, by turning it off this also saves receiving all the faxed junk mail.

As I said earlier, use it , enjoy it,  make it work for you, just don't waste it, I might add that I don't consider warming the tea pot to get a better tasting cuppa as waste and if I do boil a little too much water for the brew, this boiled water can easily be used to scold the dish cloths and waste pipes etc, this saves on the use of bleach.

"replace your old light bulbs with low energy light bulbs and  very quickly recover the cost in saved energy":-

For those not familiar, the stated watts is the amount of electrical energy that would be consumed in one hour,  the light bulb for instance, on for approximately 1000 hours per year, if this were a standard 60 watt bulb, its consumption would be 60 KWhr, cost at 10 pence per KWhr would be £6 per year, if you replaced this bulb with a low energy bulb consuming just 11 watt then the consumption would be 11 KWhr, cost  just £1.10 per year, a saving of almost £5 per year per bulb. When I first purchased these bulbs their cost was extremely high, £12 or so, now you can get them for as little as £1 each, the payback period therefore is extremely quick and so they are very well worth considering, don't through away your old light bulbs though, these can be used in areas where only short duration lighting is required, I use my old bulbs for lighting to the hall stairs and landing, outside sheds and passages, obviously as these fail, they will be replaced with low energy bulbs. I should add at this point that  although the manufacturers compare the light output of 60 watt ordinary tungsten lamps with that of 11 watt low energy lamps, from my experience 18 or 20 watt low energy lamps are closer to the light output of a  60 watt tungsten lamp but even so, there is still a significant energy saving to be made. Whilst I stand by this word of caution for older style low energy lamps, I have noticed that  the more recent low energy lamps do have a much improved light output and are quicker to reach full brightness.

A point well worth mentioning, unlike the traditional light bulb, low energy light bulbs concentrate most of the absorbed energy into light output and very little to heat output this has two major advantages, one, the life of the lamp holder and wiring is significantly extended and two, there is far less discoloration to surrounding surfaces

When replacing light fittings, try to select from those which are low energy or those which will accept low energy lamps, the lighting supplier will often be pleased to help with this

Outside lighting, consider whether it is really necessary, if it is, say from a security or safety point of view then so be it, look at the length of time that the lighting is operating, I have seen outside lights that are controlled from just a photo cell and on a dull day the lights have remained on throughout the day time. better maybe, a time switch set to actual hours of darkness

"reduce water consumption" :-

W.C flushing

There is a saying being circulated at present, " if it's yellow let it mellow, if it's brown flush it down". Whilst I can see the reason for this in terms of saving water, I am not happy with the effects on cleanliness in adopting such a principle. We do however use less water than maybe the average couple because when one of us goes for a wee, knowing each other fairly well after some 50 odd years of being together, there is often a cry heard "anyone for a wee". Combining this activety (er, not at the exactly same time! but two wee's per flush), every so often does save on a number of flushes per day.

We also have the usual water saving device of a plastic bag placed in the cistern (typically supplied free from the local water supplier) and which saves a litre of water per flush.

Take a shower rather than bathe, easily said but not necessarily true, many modern day showers can actually use more water than that required for  bathing, fortunately I do enjoy a shower and mine is of the non forced variety and is complete with a small shower head and so in this instance does use less water than that required for bathing

Garden irrigation /car and window washing

My complete rain water system supplies about a third of our total water consumption, but there is a simpler way of catching at least some rainfall, the introduction of just a rain water butt coupled to each of the main down pipes can be a very useful addition for the irrigation of the garden area and washing the car and windows, although the latter two activities do require that the water is free of most of the debris associated with rain fall. I have noticed with my rain water system that rain water is very good for cleaning jobs because it does'nt contain limescale etc and therefore does'nt leave these traces when it dries out, in fact I just leave the car to dry naturally with no streaks, less work for me - I like it!

"Replacing appliances, only when the need arises":-

When any one of our appliances finally fails and needs replacing, we look for an 'A' rated appliance, mind you, I think that the standards should have harder for the manufacturers to attain, it seems that the manufacturers of these appliances can all too easily achieve these high "A" ratings. We also look at the yearly consumption figures which can differ quite significantly between models.

"reduce heating, hot water requirements"

Check the room thermostat, can it be reset slightly lower and still maintain a comfortable living temperature, is it accurate enough, I have seen thermostats with differentials of more than 2 deg C, this creates discomfort in that the setting typically has to be higher than comfort level so that the room temperature does'nt fall too low before switching the heating back on. Result you sit there either being roasted or freezing, to coin my wife's expression.

Check the boiler operating temperature, trial and error will guide you to the lowest acceptable water temperature for maintaining room air temperatures. Particular attention should be given to condensing boilers as these type of boilers operate at  higher efficiencies at lower water temperatures, certainly the return temperature should be no higher than 50 deg C

Reduce the setting on radiators in rooms which are not used, shut the door.

Set the time switch that controls the domestic hot water cylinder to times which reflect more closely your activeties.

A warning, don't reduce the control temperature of the domestic hot water to below 60 deg C, all the nasties which are present in your typical water supply are killed off at this temperature and above.

Patio heaters Uhh!  no further comment

The high volume sales of open gas fires, with an awful efficiency in the order of just 30% (that is 70% of the energy wasted up the chimney) and the need to punch a large "fresh air" hole in the external wall of the house for safety reasons has always somewhat baffled me. I think one of the reasons that the sales "get away with it" is that the customer is only told part of the truth at the point of sale, I'm sure that given the full facts of just how much these fires cost to run, many folk would reconsider the purchase.
electric fire modification
On the subject of fires, I like many households, have a focal point electric fire in the lounge, we only use it for the decorative effect, never use the electric heating element and so now that LED Christmas lights have become readily available and quite cheap, I've found another purpose for them :-
I have removed the power lead to this fire, removed the two 60 watt lamps and thermal rotors, covered the whole base in reflective foil, and carefully placed two sets of LED string lights on top of the foil, replaced the log effect top.
The one set of string lights is multi colour and variable flicker effect whilst the other is red and static, they work well together in producing a very nice effect under the logs. Their total wattage is just 5 watts, 5 watts per hour.
Previous power requirement 120 watts per hour, now just 5 watts per hour and the effect is more realistic than before, happy or what!
A note of caution, the fire must be fitted with a permanent earthing wire


It seems official now, according to some experts, dishwashers are more environmentally friendly than hand washing. Personally I dispute these findings, I don't think that they take into consideration all that is entailed, the initial production and transportation costs of all the components, servicing, breakdown and final replacement of the dishwasher afterall, these modern day dishwashers are not that long lasting, a few years at best. All that said, whatever the cost to the environment, whilst dishwashers continue to be sold, my wife and I will continue to enjoy this modern convenience. As I continually say, use it enjoy it, just  try not to waste it.

back to top

condensing boiler

Back in the early 1980,s I designed and installed my first gas fired 'condensing' boiler system to a large hotel bedroom and conference center, although at that time it was referred to as "a boiler system utilizing both the sensible and latent heat contained in the exhaust air from the boilers", which is rather a mouthful but effectively it made use of a high proportion of the heat that would otherwise be wasted in the exhaust gasses, and it worked in a similar manner to the present day gas condensing boilers.
This principle always works best at lower temperatures and so it is very important that the system of radiators being served by this type of boiler are suitably sized so that the boiler return temperature can remain below 50 deg centigrade (a lot lower than conventional systems where the radiators rely on temperatures quite often in excess of  80 deg flow and 70 deg return to do their job) and so this  means that in many instances radiators should be increased in size so as to offer the same heat output to the rooms at these lower water temperatures.
Condensing boilers serve underfloor heating systems very effectively because underfloor systems are designed for low temperature operation, the lower the operating temperature the better the condensing boiler will work.

So when someone offers you a condensing boiler in place of your existing conventional boiler, ask the question :- at the very necessary lower operating temperatures of the boiler, are the existing radiators still going to be suitable for the purpose of properly heating the space. If the answer is yes, question it further, it maybe of course that the answer is perfectly reasonable if the radiators were say, installed prior to the addition of energy saving products such as wall insulation, double glazing etc and in which case the radiators may now be somewhat oversized and therefore will happily output as necessary at the lower water temperatures provided by the new condensing boiler


phenolic foam insulation board (my favourite)

As you read through you may have already guessed that insulation particularly for new build projects is my favorite of all green products and has a multi purpose role in that it not only 'saves the planet' but also provides us with comfort and noise reduction, I have looked at details on both the so called environmentally friendly products and the so called not so friendly products for my swimming pool enclosure, I chose the latter in the form of phenolic insulation panels at 140mm (2x70mm) thickness, the friendly insulants generally needed to be much thicker than this to provide the same insulation value and so the building would have had to be somewhat larger to contain this extra material in order to maintain the same internal dimensions, that means more building materials required and therefore more cost to the environment. Plus I believe the phenolic panels whilst they maybe more damaging to the environment in their initial manufacture, because they are in solid sheet form, will be around for a very long time, in that they are much easier to recycle at the end of the buildings life. I would like to believe that my insulating panels will be providing energy reduction for generations to come.

Payback on insulation, because of its multi purpose role,  is not so critical, that said , the payback is impressive, possibly best of all products out there. My pool enclosure for an example, the cost of the insulation panels  and additional building materials to support the product was £4000, this cost is recovered in two ways, firstly the capital cost of heating and ventilating  plant was greatly reduced as a direct consequence of the predicted lower building losses, in fact my problem was finding a boiler small enough, I ended up with a 3 KW domestic hot water boiler which serves all the heating requirements to the swimming pool water, space heating and hot water for showers etc. Secondly, the continuous reduced energy needs of the building over the life of the building suggests that this insulation will repay its debit to the environment many times over and will continue to do so for generations to come so long as when the building finally meets its end, the insulation is recycled, and  unlike some insulation products, these panels easily recycle as for the most part they are still in their original 2.4 Metre x 1.2 Metre x 70mm thick sheet form.

A point well worth noting about insulation, lower levels of insulation have a fairly quick payback period because of the somewhat low initial capital cost, together with the dramatic difference in heat loss against a non insulated building, as the thickness of the insulation is  increased, the capital cost also increases but the difference in heat lost from the building reduces and so the payback time unfortunatly increases. There is however an extremely good argument for going that extra mile when selecting  insulation thickness because the level of thickness of insulation can be easily reached where a conventional central heating system is no longer required and obviously at this level there would be a major reduction in overall capital expenditure. plus major savings in energy and running costs leading to a very much quicker payback period

One major consideration when designing  insulation into a building is that of condensation forming on the EXTERNAL surfaces of the external walls and roof which can damage the structure, I believe there are two ways to deal with this, breathable membrane or traditional non breathable, because I am not familiar with the former, I chose the traditional method which is simply a PVC membrane added to the internal structure prior to the insulation cladding, it is extremely important however, that this membrane is totally air tight, the smallest gap will allow internal air to escape and in so  doing, condensation on the outside structure will ensue, I know because there is one small point at the rear of my building where this occurs, fortunately all of my structural timbers are tanalised and so the damage over the years should be minimal.

glass fiber loft insulation

The recommended thickness for loft insulation now stands at 270mm which, according to the experts should give a U value in the order of 0.15 and  I have just upgraded my house loft with an extra 200mm  to bring it up to 300mm, will report later. Of course no grant available for us DIYers and so it is a case of shopping around for the best buy, finally found some on a "buy one get one free offer" total cost for me to upgrade was £150 at this level of expendature the payback period should be extremely quick. It took just a day to complete the work, a job well worth doing.

cavity fill insulation ( blind faith ? )

Two years ago, I purchased cavity wall insulation for my house because I was told that it could save me £190 per year in energy reduction and so at £200 capital cost this sounds too good to be true, well so far it has proved that it was far too good to be true, I intend to look into this in a little more detail and will report. It may be that the installation is at fault, ie that there simply is not enough insulant packed into the cavities, trouble is, you cannot see the product or just how much they have used, talk about 'blind faith', of course very often it is also down to exaggerated claims based on the most ideal theoretical situation that simply does not exist in practice. You may have noticed already that these sort of exaggerated claims are very much a source of annoyance to me.note the empty void, where's the fill?

Original sales pitch................"my 3 bed detached house with cavity fill will save £190 per year in energy reduction"

Theoretical "best possible"savings based upon the square area of our walls, degree days and the improved "U" value £120 per year  (I calculated this following my disappointment with the actual results)

Actual savings which were based upon a two year period immediately following the cavity fill £32 per year, at best !

Based on the actual savings this still results in a 7 year payback period which under normal circumstances would be acceptable, my concern however is two fold, one being the exaggerated claims by sales literature encouraging us folk to part with our money and secondly, and very much more importantly, the failure of the product for whatever reason to perform. This leaves our house and possibly many 1000's more underachieving and therefore continuing to place great strain on the worlds resources.

Still, I've got the paperwork in place which tells everyone that my house is of a certain energy rating, It is sad to say that paperwork very much over rules factual in many instances in today's society

Cavity fill update  :- I have today 19th September 2007 received a reply from the original sales organization, a very large well respected company. I now have an apology for the failure of the product installation but much  more important, the estimate of possible savings has now been reduced to a staggering 58% of original which endorses my argument about exaggerated claims.They haven't put figures specific to my property to this but I presume that the original estimate of savings of £190 would now read £110 for future potential customers and strangely enough, if you notice my original calculation for the "best possible"savings on cavity fill to my house above ie £120, this new figure of £110 is a far more reasonable estimate of savings, in fact it is very possible that with a complete and proper cavity fill to unrestricted cavities there is a chance that this estimate could even be met. My pitiful energy savings equating to just £32 per year unfortunately still stands and it is now for me to decide on the next stage, it has been offered to me but do I give the installers a third chance to fill the cavities or do I draw a line under the whole sorry saga. One thing I do know is that with the present methods and supervision of cavity filling, I would not allow another property of mine be subjected to this and I still wonder how many 1,000's of other properties are affected in this way.

Cavity fill update :- I have had my original money paid back to me, and will now use this money for the purchase of expanding foam in an attempt to rectify some of the failures of these so called professionals

I much prefer to do these jobs myself, I know then that it has been done to the best of my ability, DIY lives on!

under floor insulation

Because my swimming pool enclosure was new build, 120mm under floor insulation was provided to the pool floor, pool walls and general floor areas to obvious advantage, my house on the other hand, being existing, I have not fitted any under floor insulation. Only about 10% of heat is lost downwards and so the possible reduction in lost heat this way does not in my opinion warrant the disruption of adding insulation to the existing concrete floors and the disruption of adding insulation to the underside of the wooden floors. If I were to build a new home or add an extension to my existing home, then with out question, I would opt for high levels of insulation to walls, roof and floors.

back to top

draught exclusion

My next favorite method of energy reduction, needs little DIY skills and it need not cost much, but can have a major impact on the energy savings.

My swimming pool enclosure has a PVC membrane which envelopes the whole building structure and so draught is not so much of a problem, it is generally confined to the crackage around the double glazed units and so the mechanical ventilation provides constant controlled air change needs.

My 1960s house on the other hand was like a barn, I was losing at the very least 25 % of my heat because of air flowing fairly freely through the rooms, over a period of time, some years in fact each time I decorate, I seal the floor boards and skirtings. The cable holes to light fittings and switches also present an easy path for uncontrolled ventilation. I have adopted various methods of sealing all these undesirable air passages, ranging from duck tape, silicon sealants, flexible cement based mixes.

I find each time that a room is decorated the sealing process improves,  and so eventually I hope to have reduced these losses to more like 5 %. windows and doors will continue to provide some uncontrolled ventilation but the main ventilation will be controlled mechanically. I know that carpets are not so popular these days, but they do provide a good barrier to draughts and they do offer some thermal advantage.

Double glazing

Double glazing obviously helps with the reduction in energy consumption, other advantages are the reduction in noise transmittance, elimination of condensation on the cold glass surface and reducing those annoying cold down drafts that are experienced with single glazing. Mind you, again, if I had the strength, this is another job best done by D.I.Y.. The professional installation that I received failed to address properly, the question of sealing around the frame so as to keep droughts to a minimum, in fact the only barrier between the internal and external is a pathetic bit of their favorite material, the dreaded silicon sealant. 

back to top

controlled ventilation

There are various systems available, I shall describe the three systems which I have incorporated.

Toilet vent

Some years ago I tried unsuccessfully to patent a system of toilet pan vent, using the actual flushing pathway of the pan itself, I even had a name for it, the Ventilav, and was ready to market the product, unfortunately some years earlier, someone had already patented a similar system. I have yet to see the fruits of this patent in the shops. However mine has been operating just in my home for a number of years quite successfully and saves considerable heat loss when compared to the conventional high level fan. Major advantages of pan air extraction are :- because the point of extraction is immediately above the point of creation, if you you get my drift, very little air extraction rate is needed and so this extract rate is provided with ease, by a tiny 12 volt 5 watt fan. The fan run time requirement is greatly reduced again because of localized extraction point and any air path contaminates are flushed away each time that the toilet is flushed.  Maybe this product will eventually reach the shops, I wait with interest. My present day system comprises a 32mm pipe inserted into the flushing pipe and this new pipe extends to a higher point than the cistern, outside of the house. At this point, I mounted a 5 watt 12 volt fan, it is very simple in operation in that when we need to, we switch on the fan and this continues to run for a period of time after use, the pan is flushed in the usual way and whilst the water is passing down the pipe, the air flow is intermittently interrupted, this has no effect on the fan but at the same time, the water flushes out the air paths and keeps the whole system contaminate free. 

pool cabin vent

The ventilation system to the pool cabin comprises air filters, a tiny input fan 5 watt 12 volt, exhaust fan 10 watt 12 volt, an air to air heat recovery unit referred to as a plate heat exchanger, this continually operating system which purposely has no control devices, provides all the basic ventilation needs of the building and typically the humidity remains at approx 50% throughout the year, the plate heat exchanger returns over 70% of heat that would otherwise be wasted, back into the building

ventilation specific to the pool- to create slight negative air pressure to reduce the likelihood of hot air penetrating the external fabric and thereby causing external condensation. If the pool was within the home structure, a negative pressure would also reduce the escape of pool smells into the living space

Whilst much of the air heating to the cabin is provided by solar, there is a small fan heater which provides a constant base heat to ensure that the air temperature always remains at or a degree above that of the pool temperature. A lot of people make a fundamental mistake with indoor swimming pools believing that to heat the pool water is top priority, but if the air temperature is below that of the pool temperature, excessive evaporation and condensation occurs. To heat the air above the pool water is of much greater importance than to heat the pool water, and because this is true :-

my heating controls give priority to air heating rather than to the pool heating

house vent

The ventilation system to the house is similar to that of the cabin, the differences being, it is not of continuous operation, it operates on demand,  the input and exhaust fans are mains voltage, 24 watt. Note, the plate heat exchanger returns approx 60% of heat, the reason for this lower efficiency is because the air from the house is somewhat drier than that from the swimming pool, and without going into too much technical (sensible/latent heat properties) this reduces the amount of heat that can be extracted from the house exhaust air.Also a note of interest no matter how high the summer time temperature gets, the external night time temperature, with few exceptions, is no higher than 17 deg C and so I provided, two 24 watt summer cooling fans which take advantage of this cool night time air temperature so as to cool the house ready for the following day. All incoming air passes through an air filter.

The existing brick chimneys make an excellent path for the ventilation ductwork, I have used the top end of the chimneys as main exhaust and fresh air intake and the lower parts of the chimneys for extraction from the kitchen, and supply air to the lounge. The chimneys therefore can no longer be used for conventional fires, but I have no problem with this and have no intention of ever wanting to return to conventional open fires and certainly not to open gas fires as these in my opinion were both extremely inefficient and potentially dangerous. 

ventilation specific to the house- to create a slight positive pressure, to reduce the ingress of external draughts and so to reduce the ingress of dirt

When designing ventilation equipment I tend to oversize ductwork and 'in line' equipment so that the overall system air  resistance and pressure is low, the lower the system pressure the smaller the fans need to be and and so the electrical consumption is also low, it is worth also ensuring that the air rate is also kept as low as practical, if you double the required air flow rate, the fan has to be much more powerfull and so the electrical consumption and therefore the cost of running the fan quadruples

back to top

storage of heat energy for later use

Any solid material mass stores heat energy, some better than others, masonry is one of the common storage elements because most of our homes are built with this. It helps to even out the varying temperatures of the day. electric storage radiators use this material so that cheap rate electrical power is used over night to store up the heat and then through the following day this heat energy is released into the home.

There is another material recently introduced, its called phase change material (PCM)and gets its name from the fact that as it heats up it changes from solid form to liquid form. and it is this change in state that gives it an advantage over other storage materials, because that change of state absorbes additional energy in the form of latent heat  it can also be mixed such that it will change state at specific temperature levels. in other words size for size it holds larger quantities of heat energy than other materials 

At present, my largest single heat store material is my swimming pool water, 28,000 litres of it in fact and surplus heat from the solar roof is discharged into this water in two ways, 1:- by way of a coiled heat exchanger in the hot air path and a small 12 volt water pump.  2:- a water coil in the solar roof together with a small 12 volt pump.

storage of electrical energy

If you really do feel the need to produce your own electrical power, the best form of storage is to use the national grid, ie to use directly that which is made available from whatever renewable source you have and to top up as necessary from the grid or return into the grid any surplus power from your renewable source, that said, I have found that the red tape surrounding actual selling of locally produced electricity back to the major energy suppliers to be very off putting to say the least and at the time of writing this, they still insist on charging for the installation of an export meter which somewhat errodes any payback period.

If your renewables production is to be self contained, then a battery set of appropriate size is still the only reasonable answer, storing surplus energy and feeding it back to you as required. Battery packs however are very damaging to the environment both in manufacture and disposal. My old lead acid battery set however is over twenty years old and still going strong 

back to top

rain water collection

mains cold water travels an enormous amount of miles and goes through many processes before entering your property in a fit state for drinking purposes, it seems such a shame then to abuse this quality of product by flushing it down the loo or watering the garden. a lot of this water begins its very expensive journey having landed on your roof in the first place, so why not interupt its journey at this point and use it 

There are a number of commercially available rain water collection and treatment schemes, none of which have I had any close experience,  I have however, designed and installed three separate systems, the earliest back in 1994 when there was very little equipment specifically for the purpose.strangely though, my first system was somewhat close to the present day commercial systems, in that it utilized conventional rain water down pipes, stored none filtered water and as the water was required, was filtered and pressurized through a standard pressurization unit before being delivered to the outlets. Unlike a number of present day systems though, I did not include a mains water connection to the rain water storage tank for "top up" purposes, I believe that it is wrong to use potable water in this way, not to mention double handling, all of my systems will continue to be totally independent of the mains cold water supply. There were a number of sophistications added to this early system over the years such as :-

Reverse osmosis unit, which in essence is a very fine filter unit capable of removing virtually everything from the water leaving it comparable to that of distilled water, this unit was installed so that the rain water could be used for drinking purposes, however it was quickly realised that in this state, drinking it on a regular basis maybe over a number of years, because of the hungry nature of this type of water, it could possibly leach the enamel from your teeth, and so the addition of minerials was needed in the form of a mineralisation unit.

Rain water self clean filters of various types were retro fitted, all were based upon the coanda effect, which in essence is a perforated stainless steel sheet which when water passes over it the clean water is encouraged through the specially shaped fine holes whilst the dirt and debris flow away to the drain, it is typically about 90% efficient in terms of water collection, ie 10% of the collected water is lost along with the dirt and debris. My experience of these so called self cleaning filters, is that they do silt up and do require cleaning periodically and if this is not done the efficiency of collection drops dramatically.

My house and swimming pool roofs collection system

visually, not too much difference between normal rain water pipe and the 2" pipefrom main roof of house off the garage roof3000 litre tank under this sitting areashows the sand filter and bag filtersI must clean this up at some time

Just prior to the excavation works for our swimming pool, I laid various pipes on the ground at existing garden level, knowing that these pipes following excavation would be buried to a depth of at least 200mm. these pipes were laid to various collection points both for the house and cabin roofs. as part of the excavation work a hole was dug for the collection tank. This hole was lined with concrete and was complete with a fill system which combined all the collection pipes, a sediment tank, filter housings and overflow. This being my third rain water system, there were a number of ideas which I wanted to put into practice, one of the main ideas was as follows.

Unlike some systems I wanted the collection tank to hold filtered water and to effect this, the incoming rain water needed to be under pressure to negotiate the filter medium, this I acheived by using 2" PVC welded pipe extending from roof level this gave a working pressure of up to 3 metres head and together with the large face area of the bag filters has worked quite successfully, although some time ago, I  introduced a sand filter in place of the bag filters to see how this compares, sand being locally obtained, I thought if this is successful, it'll be cheaper, the bag filters cost £9 plus delivery and needed replacement once per year, I am hoping that with periodical backwashing the sand filter will give long service

I am impressed with the results so far, the system provides one third of our requirements all year long, our total water consumption being 110,000 litres per year of which 36,500 litres are provided by the rain water system, it could possibly do more but for these early days we have restricted use to just flushing toilets and showering. the 700 watt  pressurization unit is capable of delivering over* 700 litres* of rain water per hour and so 1000 litres delivered to the loos and shower as required for less than 1 KWhr of electrical power or 10 pence, even adding on the cost of the filters, we are paying less than 35 pence per cubic metre of water (1,000 litres). As mentioned earlier, this system operates independently of the mains cold water and so in the event of running out of rain water, I simply manually switch over to the mains water. This is good for me, it keeps me in touch with just how well the system is doing.

My contents gauge consists of a "U" tube arrangement, filled with a small amount of water, positioned in the house and one side connected through to the in ground storage tank by an 8mm plastic tube which extends to the bottom of the tank, The other side of the "U" tube has a short rubber hose connected and when I blow through this, the water in the tube within the tank is displaced, then pinching the end of the rubber tube, I am able to read off, the level in the tank. The tube is marked off in number of days supply remaining rather than litres remaining, it's easier to visualize.

*Note, I have just recently checked the delivery rate of the pressurization unit, which is some four years old and have found that it is now only delivering 480 litres water per hour, and so the cost of handling the water has risen, maybe to about 15 pence, still a very good return, that said, it just shows that continually measuring the energy taken is a worth while excersize


We installed a double  glazed conservatory, purposely without heating I might add, a couple of years ago and, whilst it was a life style choice, it has reduced heat  energy lost  from our home, we have noticed that whatever the outside air temperature, the temperature in the conservatory is always some 3 deg C higher, this conservatory extends over 10 square metres of our home's external wall/window surface and so we can calculate that without any solar gain (a highly unlikely scenario) there is a saving of approx 225 KWhr of heat per year, this is not much but when you consider the amount of sun shine we get over the heating season, this has an enormous effect on the energy saving, just today for instance, the outside air temperature is just 2 deg C but with a little sun shine we notice that the temperature in the conservatory rose very quickly to 17 deg C. a whole 15 deg C higher virtually eliminating heat loss from that area of  house wall and window. I haven't the facilities to calculate the solar gain effect over a whole year but it would be an interesting experiment. Obviously because ours is an existing house, there was little choice on the location of this conservatory but fortunately it faces east and catches the morning sun, heating the space for later in  the day, neighboring trees also block out some of the effect

free heat to domestic hot water service

I have just completed (October 2007) a scheme whereby the heat contained in the waste exhaust gas from an already high efficiency boiler is used to heat the domestic water in a specially designed storage cylinder, the waste gases are drawn down through passages within the cylinder and in doing so, release the contained heat through the walls of these passages into the stored water. Certainly in the early stages of demonstration, the effect is quite dramatic with a substantial temperature rise of the stored water. Do not try this at home, this sort of work is only achievable with full knowledge of the characteristics of combustion / flueing etc, and constant monitoring, but it shows that boiler manufacturers may still have some way to go before optimum use of fuel is achieved. Pictures to follow
The temperature of the flue gas in this instance is in the region of 100 deg C and is therefore perfectly adequate to heat the domestic water to beyond the "safe" limit of 60 deg C. If this were a condensing boiler with flue gas temperatures of just 60 deg C then although the same principle could be applied, the flue gas would only serve to preheat the domestic water prior to being fully heated to the required temperature of 60 deg C by whatever means, but even so, there is still a saving to be made.

Conclusion, saving energy provides us with comfort and is the most rewarding activity

back to top


My home energy.co.uk

   grumbles   swimming pool   figures  home   payback   saving it
solar   wind   water

making it

From my experience, making energy from renewables is the most complicated and least rewarding of all green practices, I would suggest very close appraisal of any product, look further than just the glossy brochure, ask questions of other people who maybe have tried the particular product (especially if your intension is biased towards saving yourself money rather than saving the environment) before venturing down this path.

There maybe free energy out there in the form of solar, wind and water, but the collection of it certainly is not free !


electrical production

600 watt theoretical electrical output, how effective are so called green products ? .There is a portion of my swimming pool solar roof covered by photo voltaic panels (PV s) with a theoretical value  600 watt hour electrical production. This is not however an endorsement of PVs, far from it, having worked closely with PV s over the years I had made a decision not to purchase because the payback period is extreme to say the least, however, having been offered second hand PV units and already owning a set of second hand cells which form quite a large electrical battery, it seemed sensible to include this feature into my overall scheme if only to reaffirm my belief that PVs offer no benefit as a green product to a normal grid connected home. if one considers the normal cost of PV s at around £10 per watt, then the installation of my little lot would have cost about £6,000 plus battery and materials, in practice I am finding that these are producing approx 300 to 400 KWhr per year ie £30 to£40 per year, and therefore the payback period would be well in excess of 130 years at todays prices and this assumes no mechanical or electrical servicing required. I should say at this point that my PVs whilst they are facing due south are not without some shading from a neighboring tree and are at a fairly shallow incline.but this just shows how important positioning of these PV s would be so that they could even begin to recover some of  their environmental debit. I mentioned electrical servicing and on this subject, I have just purchased distilled water for the battery, admittedly large, approx 25 KW of electrical storage capacity, and admittedly I have purchased 25 litres which should keep the battery topped up for a little while, but the cost of this water was £16 which somewhat eats into the yearly payback figure. I am convinced that present day photo voltiacs are not beneficial on a grid connected property. They do have a very important role to play in providing power at remote locations and it is also possible that future development will produce thin film PV's with a better cost/payback ratio. Our PV's do however supply electricity through the summer months for our swimming pool ventilation, house ventilation and evening lighting, but through the winter months, at best keep the battery topped up which in turn does at least provide us with emergency back up power if our mains power was to fail.
Because of the fact that series connected PV cells only output at the level of the worst cell performance and because I do have an intermittant shading problem, my PV panels of which there are twelve times 50 watt are connected in parallel, which means that if one panel is shaded, this panel does not affect the others, this results however in my set producing power at just 12 volt which is OK but requires somewhat larger cabling because of the high current requirements.

From my experience, present day PV's never output thier theroretical power, have an extremely long payback period and should be considered very carefully

25 KW or there abouts,electrical storage capacity

heat to water

My swimming pool roof incorporates a small area of metal foil, approx 2 square metres, with silicon piping on top, all of which are under the metal tiles, pool water is pumped through this and absorbs heat off the underside of the metal tiles, best I have achieved from this DIY project so far is 600 watt per hour, on today's costs this is a return of approx one pence per hour when the sun shines in warmer weather, ie should achieve about £6 per year return, not bad for the small initial costs involved. but I am still experimenting with this little project
There are two distinct types of commercially available solar hot water collector, flat plate which provides useful heat to water in warmer weather, not so hot in the winter months. Main benefit is its lower capital cost. Then there is the evacuated tube type which provides useful heat even on cold sunny days, from my experience these have a higher maintenance involvement and are of higher capital cost. there are many articles on these different types

heat to air

When designing my swimming pool roof, I included extra roof membrane at a small extra cost and this I formed into an envelope which covers approx 70% of the south facing side of the roof, air can pass through this envelope and as it passes it absorbs solar heat from the under side of the metal tiles, on a good sunny day this can easily achieve 3 KW per hour and more for the cost of  running a 10 watt fan.The fan is powered off the sun and is simply controlled by a thermostat positioned in the envelope and which is set at 35 deg C. On today's costs this is a return of about 6 pence per warm sunny hour and so at about £36 per year saving, the payback on this DIY project is well within the first two years. This air enters the space sometimes in excess of 50 deg C, it also passes over a water coil which serves part of the swimming pool heating.


elctrical production

I have worked closely with a Midlands based Customer who has had wind turbines for many years, I understand from his records that there is typically around 1000 hours of usable wind per year and this is with 12 metre high masts on a fairly good site ie just over a 10th of available hours in a year and so 1 KW of installed power, on a fairly good site should provide in the region of 1000 KWhr per year, on todays rate that would return approx £100 per year. If the original investment cost is around £1000, then this could theoretically return the original investment in around 10 years, assuming there is no maintenance required.
I am not convinced that these small wind turbines are beneficial either to the environment or the pocket, and particularly not at low locations, sides of houses, close to trees etc where there can be excessive turbulence which can cause fatigue damage and shorten the life of the turbine.


electrical production

Saved the best electrical production method to last, if you are fortunate enough to have a stream with a significant flow and fall running through your property, then unlike solar or wind, the electrical output from an installed water turbine can be of  a more constant nature, or at least through defined seasons, the calculation for deciding the size of unit is fairly simple, litres per second times working head in metres times (acceleration, the figure 10 is good enough for this purpose) then the whole times approx 70% (conversion efficiency) equals watts. The environment agency has to be informed and agree and in fact they may charge you for abstraction but I last heard the figure to be approx £9 per KW of installed plant per year. If the estimated water flows are used conservatively and the installed turbine is undersized, unlike solar and wind, it is possible to obtain up to 8760 hours operating time per year ie continuous operation and so a 1KW machine could deliver up to 8760 KW hours, an impressive return for a machine which would cost very similar to that of a wind turbine and a lot cheaper than photo voltaics. There are however maintenance considerations mainly to do with filtration and silting up, not to mention the usual problems surrounding mechanical products


My question still remains, how effective are so called green products ?

back to top


My home energy.co.uk

   figures grumbles   home   payback   saving it   making it

 energy saving     energy collection   energy storage   solar roof      small things, big difference    

the cabin incorporating swimming pool energy management  swimming pool cabin

My ideas on swimming pool energy management, well, they work for me!

Some five years ago and coming up for retirement, We decided to build an enclosed swimming pool (the cabin) and because we were going to do the whole job, it seemed appropriate that I should build into it lots of energy saving features, some well tried and tested, others coming with a certain amount of risk.
After all, we were all things on this project, designers, civil engineers, builders, services installer, client and end user, and so if anything went wrong it would be our problem, no one elses.
The first consideration was that of positioning the building, from an energy conservation point of view the obvious choice for me would have been to place this building adjacent to the house, this would ensure that maximum use would be made of the heat contained in the exhaust air from the pool building. This heat typically being of a higher temperature than that required to heat the house would have rendered the exercise of heat transfer to the house fairly simple, domestic hot water services could also have been combined. All that said, my wife was strongly opposed to the idea of having the pool this close for fear of smells escaping into the living areas, and so , in keeping with tradition, the final position was to be some 11 metres away from the house.

A point worth noting, our house heating and hot water energy use is in the order of 17,000 KWhr per year and the cabin heating and hot water energy use is some 20,000 KWhr per year, by combining these two buildings into one building would have a major impact in reducing the overall energy requirement on two main counts, one being that the domestic hot water requirements of both buildings would be combined, but more important, the heat energy contained in the wasted air from the pool building could, through an air to air plate heat exchanger be used to keep the house at comfort levels of around 20 deg C. 

Only having a slightly larger than average town garden and the fact that we didn't want the building to take over the whole garden meant that the buildings foot print needed to be considered very carefully, and whilst it was important to us that  the pool was of a good length, the width was not so important, the main energy saving  consideration at this stage in the design was that of building insulation, all these factors led us to choosing a 10 metre by 2.4 metre pool enclosed by a 12 metre by 5 metre building with 140mm phenolic insulation to all external wall and roof surfaces and  including 120mm phenolic insulation under the pool slab, pool walls, floor slab and even the perimeter of the building, albeit insulation under all the foundations was against builders advise I wanted to maximize the insulative effect by having an absolute insulation wrap to the entire building. To further enhance the performance of this insulation and to virtually eliminate any cold paths, the building, constructed in timber, was of two part construction, inner and outer timber frames with the insulation pinched in between.

Alongside insulation comes a problem, the better the insultive value in this case a typical U value of 0.13, the bigger the problem, that of external condensation, a very significant problem with swimming pools and it is addressed in one of two main ways Traditional solid membrane, which if it is to work effectively, has to be totally sealed, no air paths. or breathable membrane, a fairly modern practice and one which I had no previous experience and so we chose the traditional solid membrane method, after all I am installing this myself and have as long as it takes to ensure a complete seal . I achieved a 99% success as it happens.
Because of the high insulation value, internal condensation was eliminated, this is usually a major problem with swimming pools, you can see in most examples where black mold occurs particularly towards the base of the internal walls, after 4 years of continuous operation and daily use, there is no sign whatsoever of mold growth, even though we have no cover to the pool, this was a life style choice, and there is a continuous evaporation rate of 23 litres off the surface of the pool water, per day. In fact the only evidence of condensation is the bottom of the double glazing, here we see beads forming in the very cold weather.

Having decided the size and position of the building and pool, another feature had to be planned at this stage, a rain water collection system which would take water both from the pool building and house roofs, it seemed sensible to lay these collection pipes on the ground on the basis that by the time I had excavated the pool, the garden ground would have been raised by some 200 mm. Excavation could now start, we had this little digger, it needed to be small to get it through the side entrance, after two solid weeks of excavation and one breakdown, the digger not me, the site was excavated, pool dug, rain water tank dug, services trench exposed , garden ruined. I had help at this stage with shifting the spoil and digging trenches.
Having defined all the levels and dimensions and positioning all the insulation panels to the pool base, floor base and pool walls, I then had help with laying the concrete over the insulation, to the pool base and floors and a brick layer was called in to build the pool walls in front of the wall insulation.The remainder of the project, every plank, nail, screw, wire and pipe, infact every other trade was carried out by yours truly over the following two years, I can honestly say it was fun.

.There is a portion of the solar roof covered by photo voltaic panels (PV s) with a theoretical value  600 watt/hr electrical production. This is not however an endorsement of PVs, far from it, having worked closely with PV s over the years I had made a decision not to purchase these because the payback period is extreme to say the least, however, having been offered second hand PV units and having previously obtained a large set of second hand cells which formed quite a large electrical battery (25 KW storage capacity), it seemed sensible to include this feature into my overall scheme if only to reaffirm my belief that PVs offer no benefit to a normal grid connected home. if one considers the normal cost of PV s at around £10 per watt, then my little lot would have cost £6000 plus battery plus installation and materials, in practice I am finding that these are producing just 300 to 400 KWhr per year ie £30 to£40 per year, and therefore the payback period would be well in excess of 130 years at todays prices and this assumes no mechanical or electrical servicing required. I should say at this point that my PVs whilst they are facing due south are not without some shading from a neighboring tree and are at a fairly shallow incline.but this just shows how important positioning of these PV s would be so that they could even begin to recover some of  their environmental debit. I mentioned electrical servicing and on this subject, I have just purchased a 25 litre drum of distilled water for the battery,  which should keep the battery topped up for a little while, but the cost of this water was £16 which somewhat eats into the yearly payback figure.

This pool building contains a number of energy management features which I intend to describe in some detail later, in brief :-

Energy saving
low energy light bulbs
very low use of pool circ pump
very infrequent back washing of sand filter
air temperature setting above pool temperature setting, reducing evaporation and chemical losses
no windows to shower room and plant room
Insulation to all external wall roof and floor areas, minimum 120 mm thickness
Double glazing, low E south facing only
Plate air to air heat exchanger recovering heat from exhaust air :-
plate air to air heat exchanger
Ventilation provided solely by 12 volt fans typically 5 or 10 watt ( like those used for cooling computers)
exhaust air provides heat energy to pool top up water (a tiny saving, but every liitle helps)
the tiny grey top up pipe emerges from the duct at the top right of the picturethe galvanized dual duct (fresh air and exhaust air) runs horizontally across the plant room, with the pool water top up pipe running through the exhaust air path

Energy collection
600 watt/hr theoretical electrical power from the  sun, photo voltaics ( PVs)
600 watt/hr solar heat to pool water ( on a good sunny day)
3000 watt/hr solar heat to air, and water ( on a good sunny day )
rain water collection from the roofs of the cabin and house
energy storage
The swimming pool water, 28,000 litres, plus the concrete pool and floor structure, all help to stabilise the temperature of the building by absorbing and then releasing into the air, excess heat energy.
Future :- phase change material, a mixture of wax and oil
25 KW electrical battery storage bank, rather an old set, but still going strong.
3000 litre concrete filtered rain water storage tank plus 800 litre unfiltered rain water for irrigation purposes
back to top

small things big difference

conditioning tank
just a bucket with an overflow to pool pipe connectedthe overflow from the bucket to the pool is behind the bucket, just out of view, and the 1 micron filter bag is placed inside the black tube which sits on the bottom of the bucket, simple eh !
I found out purely from experience that the top up water was presenting a problem, it seemed that although the swimming pool water was well chlorinated, the algae which occurs naturally in mains water or rain water, was not be destroyed as it entered the main pool water. I have overcome this problem by the introduction of what I call a conditioning tank,( actually just a large bucket with an overflow outlet to the pool water), the top up water now slowly enters this tank and is directed to the bottom through a tube so as to ensure a good mix, before entering the pool.Inthis bucket I simply add a small amount of chlorine and although only a small amount, this represents a very high chlorine dose to the small amount of water in the bucket, and this seems to have cleared the problem. The top up water is controlled to just a drip, sufficient to replace that which is lost from the pool surface through evaporation. The evaporation rate off my pool is 23 litres per day ie approx 1 litre per square metre of surface area per day. I have also placed a  1 micron bag filter prior to the tank, it is quite surprising how much debris comes through with mains water.
pool pump run time
I have also found, contrary to some swimming pool suppliers advice of 24 hour operation, I am able to run the 600 watt pool water circulating pump only when heating to the pool is necessary, more like 4 hours per day and this has saved over 4,000 KWhr of electrical power per year, approx £400/year. We do however shower before entering the pool and this possibly helps enormously in reducing the normal contaminates entering the pool water.

back washing the sand filter
Again most swimming pool suppliers suggest back washing the sand filter once per week which wastes something in the order of 300 litres of water each time, not to mention the heat and chemical losses, I do this operation approx just twice per year and so far it seems at no detriment to the sand filter, I have not calculated as yet the enormous amount of water saved in this reduced activity or indeed the heat energy and chemicals saved, I do know it saves me a lot of trouble. As I said above, we do shower before our swim and I am sure this is the main reason for this huge saving.
On this subject, I should mention that I have experienced over the last couple of months, cloudy water, something that I have tried to address in various ways, extra filtration, raising alkalinity etc, but speaking with a pool company, it seems that I may have an unacceptable increase in cyanoric acid (the stabilizer ingredient in chlorine) and that this is more than likely due to the lack of dilution cause by infrequent back washing. Mind you, I am also told by the same pool company,  that I need not have used stabilized chlorine to such an extent in an indoor pool (cyanoric acid is mainly there to protect the chlorine from sunlight) and so it seems that I was given bad advice in the first instance.  I'm still learning, but would still recommend indoor swimming to anyone - it's brilliant!
when designing the cabin, my calculations revealed that the amount of heat loss through a small window which was to have served the shower room, would have been far greater than the loss caused by incidental electrical lighting to the same area and so no window is incorporated. we simply turn on the low energy light for the short period of occupancy
There is no window in the plant room for the same reasoning
The building was positioned on the north side of the garden so that all the double glazed windows could face south to maximize solar gain at no additional cost

pool water top up
The rain water top up to the pool, is served by a pipe which passes through the extract air duct, and because the top up is very slow (just a drip) this water is fully heated by the heat contained in the extracted air by the time it enters the conditioning tank. Is of small benefit but benefit none the less, it has to match the evaporation rate of 23 litres per day and so this amounts to a saving of just 9800 watt/hr per year or 10 KWhr just for installing the pipe in a particular manner. ie no additional cost and of course every little helps.

The lighting has been kept to what I refer to as subtle levels and there are of course no spot lights, the whole pool area is more than adequately lit by a total of  8 - 20 watt low energy lamps mounted in standard wall fittings, the shower area has two low energy wall lights and the plant room has one ceiling mounted light fitting housing an old tungsten lamp (when this lamp fails, it will be replaced by further tungsten lamps until my stock of old lamps is cleared)


solar roof

When designing the roof, I included extra roof membrane at a small extra cost and this I formed into an envelope, which extends over approx 70% of the south side of the roof, air can pass through this envelope and as it passes it absorbs solar heat from the under side of the metal tiles, on a good sunny day this can easily achieve 3 KW per hour and more for the cost of  running a 10 watt fan.
The south side roof also incorporates an area of metal foil, with silicon piping on top, all of which are under the metal tiles, pool water is pumped through this and again as above absorbs heat off the underside of the tiles, best I have achieved from this is 600 watt per hour but not bad for the small costs involved.
The remainder area of the south side roof is covered by photo voltaic panels (PV s) with a theoretical value  600 watts electrical production, I use the word theoretical because in practice I have found that PV's do not reach these values, in fact ours have produced a maximum of just 420 watt/hr. Having worked closely with PV s over the years I had made a decision not to purchase because the payback period is extreme to say the least, however, having been offered second hand PV units and already having a set of second hand cells which formed quite a large electrical battery, it seemed sensible to include this feature into my overall scheme if only to reaffirm my belief that PVs offer no benefit to a normal grid connected home if one considers the normal cost of PV s at around £10 per watt, then my little lot would have cost £6000 plus battery plus installation and materials, in practice I am finding that these are producing approx 300 to 400 KWhr per year ie £30 to£40 per year, payback period would be well in excess of 130 years. and this assumes no mechanical or electrical servicing required. I should say at this point that my PVs whilst they are facing due south are not without some shading from a neighboring tree and are at a fairly shallow incline.but this just shows how important positioning of these PV s would be so that they could even begin to recover their environmental debit.

Just as a foot note, my wife suffers from osteoarthritis and has already undergone one operation to replace a hip joint, but since having the swimming pool, the other hip, whilst it was considered at the time by the specialist as being in the same state and ready for replacement, has now lasted, without much pain, for a further four years. No one can tell what would have happened under a different set of circumstances and it maybe that this hip will be in need of replacement shortly (we obviously hope not) but we firmly believe that daily exercising in the pool throughout the years has helped to stave off this operation.
back to top


My home energy.co.uk

   payback   home   saving it   making it   swimming pool   figures

my grumbles

I might as well use this site to get things off my chest so to speak, and so.........

How effective are so called green products ?

The "green" industry is prone to exaggeration and over the years of my involvement in this field, so many times having to pick up the pieces so to speak, I have constantly battled against many outrageous claims because it is inevitable that disappointment ensues, I can understand  why some sales persons feel the need to exaggerate but it is inevitable that this can only lead to short term success and can be extremely damaging to the industry as a whole.   

Anyone responsibly improving their property and in so doing, helping the government to improve its overall carbon emissions target are, by the very same government, being penalized for these improvements by way of local taxation. and VAT on energy saving products. This is not fair and is contrary to the government's verbal diarrhea regarding carbon reduction incentives. If the government were serious on this subject, there are many ways in which they could encourage us folk to do more, it is little wonder that most of us just selfishly look after our own little worlds. 

I am pleased that many people are now talking about the environment and the damage we humans have done to it. Climate change, I am not so sure as to the cause, but I do know that we are not helping the situation. This however is where my pleasure ends because there are many of those speakers who have little or no real knowledge of the subject and therefore splutter out many miss truths, this can lead to wildly overestimated ideas of what can be achieved. Disappointment is inevitable.

some of the silly stuff :-

"Turn your telly off standby and save £27 per year"! I think not, infact I think maybe it's better to chuck away the telly if it burns this much energy just on standby ( mine uses just 0.6 watt per hour) and therefore if left on standby for a whole year would cost less than 60 pence total!.
A few solar collectors on a school roof - "runs their lights" - nonsence, for most of the winter they'll at best keep the battery charged up or run a few computers
cavity fill saves an average of £138 or even £190 per year in heating bills, sounds too good to be true - yes, mine has saved less than 1500 KWhr, £30 per year, still looking into this and so far without too much success, I think, when they are challenged, they close ranks!
Buy a wind turbine strapped to your roof and enjoy a payback period of just 5 years, well my experience tells me it'll be more like 10 to 15 years minimum at best and this is assuming a good site and no mechanical failures or servicing.
And many many more miss truths, we need acurate advice and assessment so that we can make a properly informed decision on what is right for us.

Just heard someone on main stream telly (July 2007), asking a family to turn off the telly and lights and play games by candle light to reduce their 'carbon foot print', it is little wonder that there are many folk think this whole subject is ripe for ridicule.


I wish the authorities would challenge the producers of all this unnecessary rubbish instead of punishing the ordinary householder, no wonder unlawful fly tipping and garden fires are on the increase

Approximately 90% of household waste is of a recyclable nature and it is very clear that the little recycle boxes provided by most councils were never going to be a long term solution. Unfortunately even in their short life there are a number of quite serious problems occurring.

An increase in litter distributed around the streets, particularly on windy days.

On occasions, I have to pick up broken glass, an obvious danger 

An increase in rodent activety

The boxes can be extremely heavy both for the householder and the collectors, particularly in wet weather conditions, this could lead to injury .

This is where it gets really daft, we are being asked to clean out containers prior to placing them into the boxes presumably as a precaution for the collectors and/or to stop animals attempting to feed  off the items. The amount of resources involved in this action, washing up liquid, water heating, mains water usage, waste water disposal, removes any possible value that might have been contained in the recycled item. Renders the whole exercise a waste of time. I also wonder just how many folk have cut themselves on the extremely sharp edges of these cans ?

In light of the excessive fines and land fill taxes (which I might add are simply passed on to us, the tax payers) it is surely time for councils to look seriously at the question of recycle .

What if :- all waste was collected as before, (the infrastructure is already in place for this), and at the depot there is in place a series of separator plant such as vibrators, air blowers etc to initially sort light heavy materials metals etc together with conveyors, manual workers employed as sorters and separators. The manual workers could be very well protected in an enclosed and healthy environment fully kitted out and protected. Even bonuses could be paid for excessive separation over and above the norm.

Householders could be asked to place genuinely non recycle material into easily identifiable bags.

Less compaction would be necessary and therefore more return journeys to the depot would be required but the rewards would be enormous, possibly a 10 fold increase in the amount of recycle material collected and massively reduced land fill taxes.

Grants for DIYers

There is a massive virtually untapped DIY army willing and in many cases, able to tackle some of these so called world saving schemes but most of us need the monetary encouragement which should be provided by grants, if only grants were to be directed to the product rather than the total installed package. It is very silly that a DIYer has to sit and watch a so called "professional" instal loft lagging just so that the grant is made available. It is very possible that a DIYer with the proper instructions will carry out work to a  much higher standard than that of a professional because it is the DIYer's own home and so more care is taken.

I am bombarded with "free" air miles, I didn't ask for these, have no intention of flying and can't even give them away, not that this would be a good idea because it just means that someone else will be tempted to add to the destruction of our environment. I have to admit that I have flown in the past, but only at the insistence of my employer at the time.I am not against people flying if that is their wish, but free air miles encourage needless flight and is just management's way of ramping up air flight popularity

I buy the Sunday news paper and get for my money over double the weight in advertising materials, CD's etc, none of which do I want and so most of  it goes immediately to recycle, surely it is better not to be produced in the first instance.  The CD's of course just go to land fill at present.

back to top