# Domestic Energy: Myths and Misconceptions



## sfag (18 Dec 2008)

Folks I thought I like to start a thread of modern misconceptions in the building industry. There are a lot of myths out there that most people believe.

I'll get the ball rolling.
*
1. The silver foil on insulation has thermal benefit.* 
The truth is it does not - well at least none worth talking about. The insulation comes from the insulation - not a piece of foil. If it was that easy Kingspan would not be in business. 
*
2. Double insulation is worth doing*. Eg 60 mil on the cavity and 25 mil on the plasterboard. 
The truth is it does not = 85 mil worth of insulation. The thinnest insulation will let most of the heat through only to heat the inner cavity. The heat will stay trapped to some extent. The thermal benefit has been proven to be negilible - not worth the expense. 
Bit like a small sea wall letting some of the water past only to be stopped by a larger sea wall - pointless bothering with the small wall at all. 

*3. Heating the hot water cylinder by an alternative heating source is worth doing.*
Its not. Its dirt cheap to heat a hot water cylinder - €1 a day via gas. No overly expensive high tech solution required. its a problem that does not need solving. 

*4. Domestic wind turbines work.*
Fraid they dont. 

*5. Solar heating works.* 
personal view here - no it doesn't - not in this country at least. This one has been discussed to well on these boards. I know people who have it says it does work but I don't believe them - and they never crunch the numbers anyway. The sales pitch that says it works even on cloudy days is just snake oil talk. I just cant conceive how it can work. Its always cloudy - plain and simple.


----------



## callybags (18 Dec 2008)

*Re: Modern myths and misconceptions*

I took this post semi-seriously until I came to the last line
"Its always cloudy - plain and simple."
this is patently untrue so I now have no faith in any of the other proclomations


----------



## sydthebeat (18 Dec 2008)

*Re: Modern myths and misconceptions*

sfag, youre on a wind up obviously....

perhaps if you back up all your claims with hard evidence we will take you seriously....


----------



## sfag (18 Dec 2008)

*Re: Modern myths and misconceptions*

I was being serious.
The first three are fact. The last two are more subjective but I argue they are true.
As for cloud cover. Ireland's sky is roughy 90 percent cloudy 90% of the time yet people are still buying solar panels. Duh?

I seriously challange all of you folks to apply logical thinking before running with sales presented 'scientific theory'. If it doesent make sense in your brain in all probability it wont work.  Solar is a good example of this.


----------



## ludermor (18 Dec 2008)

*Re: Modern myths and misconceptions*

Unless you can back up your statements then they are your opinions. By saying they are facts does not make them facts. If you are so sure about them please add a few links so we can all judge for ourselves.


----------



## sfag (18 Dec 2008)

*Re: Modern myths and misconceptions*


dublin for 7 days. Almost all cloud. Dosent improve much in the summer either.

You could supply evidence that points 1 to 3 do work.


----------



## ludermor (18 Dec 2008)

*Re: Modern myths and misconceptions*

Could you please?


----------



## z103 (18 Dec 2008)

*Re: Modern myths and misconceptions*



> 1. The silver foil on insulation has thermal benefit. The truth is it does not - well at least none worth talking about. The insulation comes from the insulation - not a piece of foil. If it was that easy Kingspan would not be in business.


It probably does nothing for convective heat transfer but helps for heat transfer via radiation.
The foil reflects IR radiation. A similar principle as to buildings being painted white to keep them cool inside, or why wearing white clothing is cooler than dark colours.


----------



## wexford dude (18 Dec 2008)

*Re: Modern myths and misconceptions*

sfag,

I agree with your point 4.I subscribe to Sustainability Magazine which took a neutral view of wind turbines and concluded that they are not worth installing.

I am fairly levelled headed guy like yourself and don't subscribe to ''green energy'' at any price.At the moment oil is cheap and quite possibly will remain so for the next 3 - 5 years.But just because you didn't dryline your external walls doesn't mean that its not a good idea.In fairness it has been proven to be a good idea that reduces heat loss and the insulation on the plasterboard can be up to 80mm.

Solar panels do work ''when installed properly''.A friend of mine has them and genuinely does not need to heat water by any other source from April - September.He didn't involve the SEI - he imported them directly from Germany himself.I have seen solar panels on new houses in the South East and they are about one third of the size of his but generally the houses are bigger.Probably installed by ''an approved installer''.His cost to supply and fit was the same as going thru SEI and claiming the grant but his panels are alot larger.

The only problem I can see is that people doing new builds don't allow for the cost of the greener technologies when they are designing their houses.If you are going to install these make the house smaller and include them in your cost.At the end of the day if you build an A-rated house for €40,000 more than a C-rated house your savings in energy use will be eaten up by higher mortgage repayments which leaves you with no saving at all.


----------



## Smashbox (18 Dec 2008)

*Re: Modern myths and misconceptions*

Light shines through even on cloudy days. Solar Panel do work, however it takes time to make the money back on them.


----------



## bamboozle (18 Dec 2008)

*Re: Modern myths and misconceptions*

isnt there some guy on here from Cork that has a website which tracks the temperature in his solar tank, 
there should be sufficient data on that to answer some of the issues raised!


----------



## clonboy (18 Dec 2008)

*Re: Modern myths and misconceptions*

i think it was irish eco plumbing is the website / guy you mean


----------



## bamboozle (18 Dec 2008)

*Re: Modern myths and misconceptions*



bamboozle said:


> isnt there some guy on here from Cork that has a website which tracks the temperature in his solar tank,
> there should be sufficient data on that to answer some of the issues raised!


 

follow the link to see the temerpatures on the tank

[broken link removed]

interesting reading


----------



## sse (18 Dec 2008)

*Re: Modern myths and misconceptions*



sfag said:


> dublin for 7 days. Almost all cloud. Dosent improve much in the summer either.
> 
> You could supply evidence that points 1 to 3 do work.


 
We're not the ones stating their unproven opinions as fact. Generally the person making an assertion has to try to prove it.

However, I'd agree with you on renewable energy, very often it's not worth it. Solar panels for DHW are a marginal decision.

Oil is now $40 a barrel, in the summer it was $150. No-one can know what it will be in 3-5 years.

SSE


----------



## Simeon (18 Dec 2008)

*Re: Modern myths and misconceptions*

I'm on sfag's side ......... the green/eco mafia are hell bent on pushing their (not too well thought out) agenda. Get your insulation done 100%, throw away your radiators and get fanned convectors (a few minutes will heat up the room) and keep the energy in. Install point-of-use water heaters. I did all this recently in an old farmhouse conversion and the savings are huge. A warm house with hot water on demand. Not a tank of water unless you require it ........ more often than not, you need to wash a few plates/utensils etc. Or for having a shave in the morning. Install an electric shower. I didn't get a BER - don't need to as it is for our own use. But I know when I'm warm. For the record I mushroomed  50mm Xtratherm onto the 21" thick stone walls, dropped the ceilings to 7'6". 300mm of rolled-out insulation above these. Dug out the old damp concrete floors, DP membrane, concrete, 4" insulation, chicken wire and 3" semi-dry floor screed.


----------



## sse (19 Dec 2008)

*Re: Modern myths and misconceptions*

I don't think it's a case of being on anyone's side. The OP posted his/her opinions as Gospel on this and another thread without a shred of evidence for any of the assertions made. Still not sure if he/she was being serious or is just a wind-up merchant, a forum character if you will.

Just because your solutions worked for you doesn't mean they are universally applicable in all situations. The only part of that which is unquestionably correct is "...keep the energy in....". You could support your pattern of use with a combi boiler, for example, to give one alternative.

SSE


----------



## MrMan (19 Dec 2008)

*Re: Modern myths and misconceptions*

I don't think sfag is winding anyone up, but it shouldn't be left alone to the one making the assertions to prove their point, if you disagree with his opinions you should provide evidence to show that he is wrong, if for nothing else only to educate the rest of us.


----------



## sydthebeat (19 Dec 2008)

*Re: Modern myths and misconceptions*



sfag said:


> Folks I thought I like to start a thread of modern misconceptions in the building industry. There are a lot of myths out there that most people believe.
> 
> I'll get the ball rolling.
> 
> ...



1. heat is transfered by three methods... conduction, convection and radiation. The closed cell nature of any foam insulation ie polystyrene, polyurethane etc counter acts both conduction and convection but not radiation. Radiation heat transfer is counter acted by reflective surfaces thus the reason for the foil layer on kingspan / xtratherm insulation. So in this point, you are completely incorrect.

2. There is some merit behind this point, as it is ALWAYS better to have your insulation as one continuous element, which may contain layers. But in some instances a second layer of insulation inside a block leaf is an appropriate way to insulate. Personally i do not like this construction and when ever it HAS to be specified, i would insist that the drylining insulation does not exceed 0.5 times that of the cavity insulation.

3. This is simply a case of 'the straw that breaks the camels back'. At the moment renewables such as solar MAY be uneconomicalm, but there is one constant that we all can count on. That is, fossil fuel prices WILL rise.... fact. Sun energy costs will not rise,and will, in fact, fall. Also under 2007 Part L regs renewables HAVE to be included in your dwelling. This does not include the personal choice many people make to provide a renewable energy source from an ecological point of view. It would be a very sad world if all everyone saw was the bottom line figure.

4. This is a silly statement. obviously they DO work, but to what degree is the question. All the points listed above in 3 are also applicable here.

5. Im glad youve included the caveat that this is your own personal view, because again you are incorrect. I know of a dwelling in Cork completely heated by solar power also, both space and water heated. I have witnessed many control panels showing heating in the region of 25-35 deg on cold cloudy winter days. I have seen temperatures in the region of 80-90 on hot summer days!!  To explain it simply there is heat in all light. the only way no heat can be transfered is if there is no light ... ie night time. Clouds do not block out sunlight altogether, they simply diffuse it.....

One thing i would agree with is simeons point about green/eco buisness. There has been a large swell in a supposed 'green' industry over the last few years. Many people find it a minefield when making decisions on buildings. For every person advocating a product theres another to lambast it.... all anyone can do is to try to get clear independant advice and trust their gut.


----------



## galwayreader (19 Dec 2008)

*Re: Modern myths and misconceptions*

Yes solar heating is overrated in Ireland. It only works 100% in July and August and 50% for May June and September. Outside this it is pretty useless.


----------



## Caveat (19 Dec 2008)

*Re: Modern myths and misconceptions*

Hmm...beginning to sound like:

_Modern myth and misconception No. 6 -_ 

sfag knows what he's talking about.


----------



## ubiquitous (19 Dec 2008)

*Re: Modern myths and misconceptions*



sydthebeat said:


> One thing i would agree with is simeons point about green/eco buisness. There has been a large swell in a supposed 'green' industry over the last few years. Many people find it a minefield when making decisions on buildings. For every person advocating a product theres another to lambast it.... all anyone can do is to try to get clear independant advice and trust their gut.



I think that was sfag's point all along. 



sfag said:


> I seriously challange all of you folks to apply logical thinking before running with sales presented 'scientific theory'. If it doesent make sense in your brain in all probability it wont work. Solar is a good example of this.


----------



## sydthebeat (19 Dec 2008)

*Re: Modern myths and misconceptions*



ubiquitous said:


> I think that was sfag's point all along.



fair enough, but you cant discount the scientific basis because of the marketing stragety..... 

sfags statement "If it doesent make sense in your brain in all probability it wont work" is really ridiculous. Im sitting in front of a computer that i have no understanding about how it actually works and how information is stored on a physical material... but i KNOW it works.
To take sfags view point we'd still be living in caves!!


----------



## ubiquitous (19 Dec 2008)

*Re: Modern myths and misconceptions*



sydthebeat said:


> fair enough, but you cant discount the scientific basis because of the marketing stragety.....
> 
> sfags statement "If it doesent make sense in your brain in all probability it wont work" is really ridiculous. Im sitting in front of a computer that i have no understanding about how it actually works and how information is stored on a physical material... but i KNOW it works.
> To take sfags view point we'd still be living in caves!!



I think you are misinterpreting his point. Its quite possible to watch TV without knowing or being aware of the technology that enables the TV to work. This is not the same as gut feelings. If someone arrives at my door offering me a magic TV that will work without electricity or an aerial, my gut feeling will tell me that he is bluffing. I don't need to be a TV technology expert to decide this. In most (but not all) cases my gut feeling will be correct. Remember that even the most eminent experts rely on their gut feelings as well. Sometimes they get it wrong. Most times they get it right.


----------



## sydthebeat (19 Dec 2008)

*Re: Modern myths and misconceptions*



ubiquitous said:


> I think you are misinterpreting his point. Its quite possible to watch TV without knowing or being aware of the technology that enables the TV to work. This is not the same as gut feelings. If someone arrives at my door offering me a magic TV that will work without electricity or an aerial, my gut feeling will tell me that he is bluffing. I don't need to be a TV technology expert to decide this. In most (but not all) cases my gut feeling will be correct. Remember that even the most eminent experts rely on their gut feelings as well. Sometimes they get it wrong. Most times they get it right.



absolutely, thats why in my post i advise to get 'independant' advice...

theres a difference between choosing to use a product or not, and choosing to believe that the product does not work... theres a huge difference actually.

sfag started this thread with some fairly outlandish statements, and whilst he/she may have been trying to make a different point, he/she still needs to back up their claims in order for them to be relevant... and posting a weather forecast isnt exactly prooving a point...

Im in the building trade, i see these products in use every day and no two situations are ever the same. Ive seem people pay fortunes to install geothermal systems into a badly insulated badly constructed houses, install solar panels onto planes of roofs that were not ideal etc.... 

so my point is, dont discount the science, the science holds up.... just do not believe the sales speak!


----------



## sse (19 Dec 2008)

*Re: Modern myths and misconceptions*

Experts do not rely on gut feeling! They rely on experience, experimentation, fact, peer review, proof and conclusions.

Experts design the aircraft you fly on. You wouldn't want them to rely on their "gut feeling" that the wings will stay on.

Five years ago your "gut feeling" would tell you that it was impossible to store music on a device the size of a matchbox. Got an iPod?

SSE


----------



## sfag (19 Dec 2008)

*Re: Modern myths and misconceptions*

Folks. I know I reduce my points to very simple one or two 'black or white one liners but I feel that one has to boil things down at the end of the day to a yes or no answer when facing decisions on what to install when building. 

I self built by direct labour a few years a go. I considered all aternatives. 

With regard to points one and two I had a kingspan 'expert' standing on my site who - despite selling the insulation -  did not recommend I double layer or pay any regards to the foil. They said it disintegrates - yes I was suprised on both accounts.
Take from that what you will. 

Yes foil may contribute a little thermal benefit but when the other technology within improves so much 9and it has) I'm guessing it's contribution is reduced to make it not worth considering. 

Regarding the wind turbines. I know a green counciller who tried one out and deemed it a failure when considering the cost of installation versus the return.

Regarding heating water - for me its a plain and simple number comparision. My gas bill for the warmest 4 months of the year is a mere €1 a day and that includes towel radiators and cooking hob. I simply cant see how spending the guts of €6000 will improve on that.


I'm undecided on the geothermal route. I know three people with it. Two of them are cold creatures and hardly ever use it so I cant compare their bills.

The third is a new installation and is a house similiar in size and energy consumption to mine. They will also run their heating 24/7 like mine.  Mine is gas heated. We both set our room theormostats to 21c. I feel direct comparisions are feasible. 

So far their last late autumn bill for electricity equaled my electric and gas combined so its not a success so far. It could be that his unit is generating heat even when the rooms arnt calling for it so I'll wait and see how thing go.

I want it to be a success because I want to switch.  I ahve plumbed and wired my house to make the addition of an alternative at some future date doable. 




Regarding green alternatives. As long as there is a 10 to 20 year wait on your return they will never succeed in acheiving mass appeal and governments will not promote them.


----------



## ubiquitous (19 Dec 2008)

*Re: Modern myths and misconceptions*



sse said:


> Five years ago your "gut feeling" would tell you that it was impossible to store music on a device the size of a matchbox. Got an iPod?



 Five years ago, or even ten years ago, my gut feeling was that this was eminently possible. Sure, isn't technology always advancing, and aren't devices always getting smaller and more portable? I'm sure the experts at Apple, Creative et al felt similarly. Otherwise they wouldn't have invested good money in developing the technology.



sse said:


> Experts design the aircraft you fly on. You wouldn't want them to rely on their "gut feeling" that the wings will stay on.



Indeed, but in any given situation, if their gut feelings are telling them that something is wrong, I would expect them to err on the side of caution, and if necessary ground the plane pending proper investigation.


----------



## sydthebeat (19 Dec 2008)

*Re: Modern myths and misconceptions*



sfag said:


> Folks. I know I reduce my points to very simple one or two 'black or white one liners but I feel that one has to boil things down at the end of the day to a yes or no answer when facing decisions on what to install when building.
> 
> I self built by direct labour a few years a go. I considered all aternatives.
> 
> ...



Renewable technologies are now an integral part of new builds. Under 2007 regs 10kwh/m2 of every new build needs to be provided by renewable sources... or 4 kwh/m2 of electricity.


----------



## Ruam (19 Dec 2008)

*Re: Modern myths and misconceptions*



galwayreader said:


> Yes solar heating is overrated in Ireland. It only works 100% in July and August and 50% for May June and September. Outside this it is pretty useless.



But surely this is when you most want hot water from solar as most people have heating on the other months which heats the water.

ruam


----------



## CharlieR (19 Dec 2008)

*Re: Modern myths and misconceptions*

Is the foil on the kingspan not for moisture protection?


----------



## chimpster (19 Dec 2008)

*Re: Modern myths and misconceptions*

Lads,

Its posts like this that drive people to get INDEPENDENT advice.

Principals of science can be applied to everything. Regarding solar, its not difficult to find the annual insolation figures for your area. Find your orientation, find your pitch, find independent test results for your tubes/panels, find your occupancy, estimate your hot water use, find the heat loss factor of your tank and finally find your net cost of purchasing the system. You can calculate your payback pretty accuratly based on this. 

The same can be applied to wind. 

The original post is by and large pure and utter pub talk. 

Anyone ever question the payback of a plasma tv, a leather sofa, an SUV?

Solar has a payback, its will be shorter for some and longer for others!


----------



## z109 (19 Dec 2008)

*Re: Modern myths and misconceptions*



sfag said:


> I'm undecided on the geothermal route. I know three people with it. Two of them are cold creatures and hardly ever use it so I cant compare their bills.
> 
> The third is a new installation and is a house similiar in size and energy consumption to mine. They will also run their heating 24/7 like mine.  Mine is gas heated. We both set our room theormostats to 21c. I feel direct comparisions are feasible.
> 
> So far their last late autumn bill for electricity equaled my electric and gas combined so its not a success so far. It could be that his unit is generating heat even when the rooms arnt calling for it so I'll wait and see how thing go.


You might want to wait until the second year, I found my geothermal costs were 25% lower then than the first year (despite prices rising), but then I have a horizontal collector bed and it may be that the soil disturbance took a while to settle back down.

On a conservative calculation (i.e. averaging in favour of more usage during the day than night), it has cost about 900 a year for heat and hot water (220 sq metre house).


----------



## Nermal (19 Dec 2008)

*Re: Modern myths and misconceptions*



chimpster said:


> Find your orientation, find your pitch, find independent test results for your tubes/panels, find your occupancy, estimate your hot water use, find the heat loss factor of your tank and finally find your net cost of purchasing the system. You can calculate your payback pretty accuratly based on this.
> 
> The same can be applied to wind.
> 
> ...



It's not pub talk. With current technology, it doesn't make pure financial sense to install solar heating, wind turbines or solar electricity systems - they will need to be replaced before they give a positive return over gas or mains electricity.

Of course not everyone thinks in solely financial terms and they may wish to 'do something for the environment'. They just shouldn't kid themselves that they're doing something for their pocket also.


----------

