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Topic Title: Green Deal Paradox
Topic Summary: Climate change predictions are for much warmer UK winters, so why invest in cold weather energy saving?
Created On: 28 January 2013 09:12 PM
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 28 January 2013 09:12 PM
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cookers

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The official climate change paradigm, http://www.ukcip.org.uk/ is that the UK will soon have a much warmer climate and we can say goodbye to cold winters.

Some have described the future UK climate "similar to the South of France" , a pleasing prospect. However before ordering the sun awnings perhaps we should take note of the following paradox.

The paradox is that the government are facilitating long term investments in improving our housing stock's cold weather energy efficiency, measures such as double glazing, insulation and heating system improvements, when according to the " official" predictions we won't get any sort of cold winters any more, so there will be little need for efficient heating.
 29 January 2013 01:02 PM
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ectophile

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Many years ago, people were talking about our climate becoming like the south of France. I haven't heard anyone talking like that recently.

The temperature rises we are looking at are around 0.7C so far, and perhaps around 2C in the longer term.

So we aren't going to get warm and sunny winters any time soon. More like miserable and wet, but not quite as cold.

http://www.ukcip.org.uk/essent...hat-is-climate-change/

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S P Barker BSc PhD MIET
 29 January 2013 02:38 PM
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aroscoe

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I' m sure our house is cools quicker in +4C windy wet weather than -2C calm weather - probably the wind chill, so I wouldn't link the need for insulation down to small increments/decrements in average temperature. And the inside of a house is 12-20C so the temperature differential change (as a percentage) is very small.

I would also summise that the solar gain of houses will be less in the slightly warmer/wetter climate (if thats what is going to happen).

All in all, I'd rather have a -2C sunnier blue-sky day than the +4C wet windy day. But, in both cases, I want my home insulated!

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Dr. Andrew Roscoe

http://personal.strath.ac.uk/andrew.j.roscoe
 29 January 2013 09:22 PM
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cookers

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I have observed that climate change predictions do tend to vary according to every passing shower.

However I have a 2001 personal letter from a doubtless charming woman at the UK Met office who assured me that their careful modeling had revealed I would soon experience a UK climate like the South of France.

I told the lady that in my opinion latitude, geography and the North Atlantic Jet stream would most likely intervene and the UK weather would remain intensely disappointing.

However, more considered observational science (not involving models) from the UK Met office does indicate a significant and sharp downward trend in the number of heating degree days and if this trend continues then the cost and carbon payback time for the "green deal" energy saving measures would likely extend beyond sensible limits.

I suggest you look at Fig 6 of this study. (the rest makes interesting reading as well, I particularly note the discussion and conclusion summary comment that there was no trend in temperature till 1987)

http://www.metoffice.gov.uk/cl.../UK_climate_trends.pdf
 30 January 2013 02:55 AM
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jarathoon

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I've just done some quick and dirty calculations on the green deal to show why it won't work in its present form.

For the sake of argument lets take a house with a current gas bill of £750 annually (south of england where heating bills are low relative to scotland say)

Lets say that spending £10,000 on insulation nets a 30% saving in the gas bill (so £225 saving in first year)

Now the savings in subsequent years depend on the gas price inflation rate.

But the green deal will be charging 7% a year interest on the £10,000 so this must be factored in.

In order a green deal loan of £10000 (at 7% interest, and initial saving of £225) over 25 years the fuel bills must rise by at least 13% a year for 25 years, otherwise the loan will not be paid off.

For my example bills need to rise around 6% more a year than the green deal rate to pay off. (for people with higher bills this excess will be lower, roughly plus 3% if your gas bill is £1000 per year, and initial savings of £300 - so you will need prices to rise by at least 11% a year for 25 years)

(I haven't worked out the sensitivity of the regime to milder winters - this needs a little software app - but the probability of not being able to pay back of couse goes up)

By taking out a green deal under the current terms you are essentially gambling that 11% to13% price rises will continue for 25 years. Why should people take such an absurdly risky gamble?

If the green deal interest is 2% above base rate (i.e. 0.5 + 2 = 2.5%) then bills must rise 5.5% + 2.5% for 25 years to pay off (i.e. at least an 8% rise per year). This is still on the high side.

If the green deal loan was interest free then bills must rise at least 5% a year for 25 years to pay off.

In order to remove risk from consumers (in the south of england with lower bills generally) the green deal must put in place a minimum fossil fuel price escalator of roughly the green deal interest rate plus roughly 5 to 6 percent. This way people don't take on the risk of not being able to pay back their loans.

However what are the political repercussions of adding an fossil fuel price escalator?

James Arathoon

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James Arathoon
 30 January 2013 08:39 AM
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ectophile

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£10000 would buy you an awful lot of insulation. I suspect that if you need that much, it will make more than a 30% improvement.

Without looking at calculated figures for real buildings, it's very difficult to do a "back of an envelope" calculation that comes up with realistic results.

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S P Barker BSc PhD MIET
 30 January 2013 10:30 AM
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jarathoon

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Sorry I was talking about externally/internally insulating solid walls, the main new target for the green deal. Cavity wall insulation is much much cheaper.

Obviously the cost is going to vary from house to house based on wall surface areas etc. Going for 50% saving will cost much more than £10,000. You will probably need to insulate under the ground floor, increase the insulation thinkness all round. Refit windows, remove plaster and insulate reveals. May need to install mechanical ventilation with heat recovery. This will bump the cost up, maybe to the order of £25,000

In terms of the £10,000 order of magnitude project: for external insulation you have to move drainage, soil and waste pipes, and extend roof overhangs and move guttering.

For internal imsulation (leaving out reveals) sills need to be rebuilt or overlayed and skirting boards need to be moved plus and electrial sevices etc.

It is entire feasible to do an order of magnitude calculations to find the most marginal upgrade likely to be covered by the green deal.

To be on the safe side you need to allow for the possibility that people will want to put their thermostat up from 18 or 19 degrees to 20 degrees after a insulation upgrade.

Upgrading insulation benefits people most (comfort wise) if they need to keep the house warm all day; i.e. for the retired or house bound or home workers.

I now accept adding an extra loft room to the house as part of a refit and renting it out may produce better returns.

James Arathoon

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James Arathoon
 30 January 2013 01:29 PM
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ectophile

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I suspect that the Green Deal will only work for "easy win" improvements like loft and cavity wall insulation. Perhaps double glazing as well.

My worry is that the installers will simply "adjust" the figures to add as much as they can get away with to the occupant's utility bills, without bothering too much as to (a) whether the cost savings are accurate, or (b) whether or not the price being charged for the work is fair.

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S P Barker BSc PhD MIET
 02 February 2013 12:05 PM
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Ipayyoursalary

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I sometimes wonder if the focus should be on ventilation rather than insulation. I've spent quite alot of money getting the cavity walls filled and the loft insulation increased but have not noticed any savings. This is probably because we like to have a window open to get some fresh air into the house - even when it's cold outside.

Personally, if I try to sleep in a sealed room, I sleep poorly and wake up in the morning with a headache and a congested nose and throat. Having a window open a crack solves the problem.

I'm not sure whether it's lack of oxygen, CO2 build up, or just drowning in one's own bad breath that does it. Although here's a calculation that suggests a human can only survive for 3 days in a completely air-tight room.

I had a quick look at ventilation systems but most seem to be glorified dehumidifiers. Seems to me you'd need a CO2 scrubber and an oxygen generator to be of actual use.
 02 February 2013 12:25 PM
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westonpa

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Originally posted by: Ipayyoursalary
I've spent quite alot of money getting the cavity walls filled and the loft insulation increased but have not noticed any savings. This is probably because we like to have a window open to get some fresh air into the house - even when it's cold outside.

Another thing we seem to forget is that decades ago because the house was colder we put on more clothes whereas now with the double glazing and insulation we just turn the stat up a degree or 2 and swan about in our T shirts.

The government and people who generate these 'reports' which lead to all these schemes do not really think these things through. Rather they just want to be seen to be doing something at the time or else getting headlines for their reports and without too much concern for the next set of problems they create, because of course then they will offer another solution and another report.

It should be obvious to us that we need a certain amount of 'fresh air', after all life on Earth did not evolve in an air tight box.

I had a quick look at ventilation systems but most seem to be glorified dehumidifiers. Seems to me you'd need a CO2 scrubber and an oxygen generator to be of actual use.


I think part of the solution will be to improve the clothing we wear.

Regards.
 02 February 2013 09:51 PM
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Ipayyoursalary

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Yes - I'm worried that these estimates of 30% or even 50% savings are far too optimistic. If you seal up all the drafts to keep the warm air in you'll only end up with a stuffy house. Open a window for some fresh air and you've bypassed all your insulation at a stroke. You need something that can turn warm 'stale' air into warm 'fresh' air with respect to O2 and CO2 content - but which takes less energy than heating external cold air to a comfortable temperature. As far as I'm aware no such device exists. With insulation alone I reckon the best saving you could expect would be 5-10%, unless you're prepared to live in a stuffy airless house or walk around dressed like Scott of the Antarctic.
 02 February 2013 10:48 PM
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ectophile

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There are systems that can improve stuffy sealed houses, but at a cost.

They consist of extractor fans and ducts, and clean air intake ducts, but with a heat exchangers between them. That way you get a constant supply of clean air, but it's pre-warmed before it enters the house.

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S P Barker BSc PhD MIET
 03 February 2013 11:46 AM
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westonpa

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Those who give the estimates are either trying to sell something or else trying to show they are doing something and so both have a vested interest in projecting the most favourable figures. The issue is that, as with the banks, nobody is actually held to account for the errors, despite all the waffle from politicians and authorities. Hence the favourable figures are allowed to be used but the relevant savings are not actually delivered.

Some years ago I had a house for 12 years and which had electric heating and so I had some direct experience of this type of heating. When I chose to do an engineering degree I decided my project would be to investigate this heating and see if I could make it more efficient. So I installed some sensors into my heaters and house and outside etc., and programmed a microprocessor to record all the date 24/7 and through a summer and winter period etc. Then I took a look around at what the companies who supplied this type of heating were saying with regards to the efficiencies they said their 'new' controls could deliver. I spoke with one of these companies and asked them what evidence they had to back up their claims and at that point the conversation became 'unclear'. I know from my studies and my evidence that it was impossible for them to deliver what they were suggesting. What they were doing was to take the maximum saving which could be delivered on a few occasions and in maybe one or two people's houses and then presenting their savings in such a way as to suggest this would be delivered on all their heaters in all houses and at all times.....they were just choosing wording which would allow them to backtrack if ever trading standards became involved.

These so called savings which are suggested are not checked by the companies or our authorites and no one is thus held to account for the errors.

Regards.
 03 February 2013 12:18 PM
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jarathoon

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Originally posted by: ectophile

There are systems that can improve stuffy sealed houses, but at a cost.


They consist of extractor fans and ducts, and clean air intake ducts, but with a heat exchangers between them. That way you get a constant supply of clean air, but it's pre-warmed before it enters the house.


That is what I meant by mechanical ventilation. I think you have to seal up all your existing vents and draughty cracks, plus not open windows to use them. They are popular in Sweden apparently, but I am not sure we get enough really cold days and nights to justify the investment.

I suspect cavity wall insulation may be of little or no value if you get a botched install that blocks vents, forcing people to open windows instead.

The 30 and 50% estimates of savings were from data on the energy savings trust website, but I can't find them anymore. Now it appears they are giving even bigger figures.

http://www.energysavingtrust.o...Solid-wall-insulation

They are now claiming £445 savings for a £5000 to £8500 investment on internal insulation in a solid walled house. With a 30% saving (which I agree is a really top end estimate for this level of investment) the original gas bill must have been £1483 for a 3 bed solid walled semi. This seems quite high to me.

Originally posted by: Ipayyoursalary

I had a quick look at ventilation systems but most seem to be glorified dehumidifiers. Seems to me you'd need a CO2 scrubber and an oxygen generator to be of actual use.


The CO2 scrubber and oxigen generator was invented by nature 100's of millions of years ago, its called a plant! Sorry!

I think you are both right that getting sufficient fresh air into houses for life and comfort (for the coldest months of the year) without using large amounts of energy or expensive mechanical ventilation systems is a key thing to think about.

James Arathoon

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James Arathoon
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