'Efficient' heating system left families with big bills

[Andrew Gabriel]

on BBC Radio 4 "You and Yours" (and presumably on Rip Off Britain) about Exhaust Air Heat Pumps (which I've never heard of before).

Seemingly these are being fitted to Affordable Housing because it means they can meet more stringent energy efficiency requirements, but the systems are ineffective, and generating massive heating bills as they fall back to electric heating.

Some housing associatios are now having to pay for the excessive heating costs of their tenents, and wholescale ripping the systems out.

[Paul D Smith]

Listening to "You and Yours" this lunchtime it sounded like a combination of...

- marketing "over enthusiasm"

- possible cost cutting causing underspecification

- building homes which are still not as well insulated as possible and no match for northern European standards.

There appears to be little in the way of facts and a lot of finger pointing. It will be interesting to see it, in the fullness of time, a proper detailed analysis of what went wrong is performed.

When one watches Grand Designs and sees totally passive houses being successfully built, it's hard not to become cynical at modern home building; the tools are there and the designs of high efficiency houses are proven but presumably it is bad for the builders' bottom line so we're stuck with crap.

Paul DS.

[Man at B&Q]

Until the end of the programme when the final cost (financial and in some cases emotional) is revealed.

MBQ

[Andrew Gabriel]

This one sounded to me like a way of fiddling some energy efficiency figure they had to meet, so they met the figure without generating energy effiency, and the system never stood any chance of being able to perform.

I've just glanced at the data sheet. It seems to have a 550W compressor (much smaller than the air sourced heat pump in my living room), which it claims can pump 1.5kW.

1.5kW is horribly low for the heating capability of a central heating system (which includes hot water generation). But then I got to think I'm not even sure it's that good - it's not an air sourced heat pump pumping 1.5kw in from outside, it's just pumping 1.5kW from the house's exhaust air. I'm still thinking about it, but I think it's heat generating capacity is actually only its 550W power consumption, and not it's heat pumping capacity as it's not pumping any heat in from outside. Add to this just the heat recovered from the typical 2 air changes per hour. Either way, it's not surprising it doesn't work.

[Andy Burns]

Are these different from the fresh air heat exchangers featured in the passive/eco houses on Grand Designs et al?

[Brian Gaff]

As with many technologies, the idea is great and no doubt could be made to work given careful choice of control logic and a really efficient heating system as well. Unfortunately the first into these new ideas often get burned and the technology gets a bad name probably wrongly. Brian

[Dave Plowman (News)]

I sort of heard it in the car, and it seemed to me the idea of waste heat from a house being able to keep it at the required temperature and supply the hot water would only work if it was very well insulated. In which case any form of heating would also have small running costs. If it can't supply all the needed heat, topping that up with electrical heat is stupid given how much more that costs than gas in the UK. That it is a decent system in other countries is neither here nor there - that depends on their energy costs for different fuels.

I felt quite sorry for the equipment supplier spokesman. Since the major things that make for low energy bills - like good insulation - were beyond his control. As presumably was the specification and installation of the systems. That all the estates fitted with it seemed to be social housing is no surprise. They seem to be controlled by amateurs.

[Owain]

"The Energy Performance Certificates which accompanied the new properties, estimated electricity costs for heating and water to range from =A3400 to =A3500 each year. But hundreds of families on housing estates throughout the UK have paid three to four times that amount."

It's nice to know that we can rely on Energy Performance Certificates

Owain

[Harry Bloomfield]

Andrew Gabriel brought next idea :

I only watched it whilst busy with something else, so I didn't digest the full details, but...

It seemed to me that it did work in Sweden, where insulation and environment air sealing is probably high on the specifications list. In the UK, where these standards are much lower, there will be much less heat to be recovered and the installation of the equipment seemed in part to blame.

[tim.....]

I though that the current standards brought us pretty much up towards that.

I live in a property built in 2000 to the previous standards and my heating uses about 2500 kWh per annum. For that usage it doesn't make sense to spend 3K (or more) on heating equipment, when a couple of 30 quid panel heaters cuts it (which is what I have - actually there are 6 but I never need more than 2 turned on).

If it had the 2006 standards I would expect to only have the heater(s) turned on for about 10 days a year!

Or perhaps, because the way that 2006 changed the measuring process a "pass" is allowed for there to be less insulation if the actual heating system is more "efficient". If so that seems to be a very serious error, not the least because further down the line when the system breaks down, so owners are not going to be able to afford the replacement costs and just go out to buy electric heaters.

(and of course, there the perverse incentive for manufactures of expensive kit to push their "solution" instead of the insulation)

tim

[Paul D Smith]

...snip...

Agreed but we're talking about very different things. These heat pumps seems to have been installed poorly, in homes insufficiently insulated and I'll bet someone made a tidy sum producing these "eco-homes".

But the residents have paid dearly for this and it's probably not their fault at all. But that doesn't make it the heat pump manufacturer's fault either necessarily (which Is how I read the original post as saying). These sorts of pumps work fine in much colder climes than ours, but where the homes they're fitted to are much better built.

Paul DS.

[RJH]

Not the first time a design has been inappropriately applied:

[Dave Plowman (News)]

One estate were told their bills would be about 500 quid a year - less than yours? But ended up at three times that. Which isn't a million miles from mine in a large Victorian house with solid walls - and I'm retired, so have the heating on as much as most. Of course where you are in the country can make a difference, but something doesn't add up.

[Harry Bloomfield]

Dave Plowman (News) used his keyboard to write :

They were having to use electric, rather than the much cheaper gas heating, to top up the inefficiencies of the system.

[Steve Firth]

One problem identified by " Saving the Earth" on radio 4 was that current planning regulations take no account of real world insulation performance. Thermal loss calculations have no element of measurement of the as-built performance.

StE found that thermal camera observation of new build Eco-homes revealed that various trades compromised thermal performance by moving insulation or by poor precision builds.

In several cases insulation had been forgotten during the build.

[charles]

[Snip]

half a dozen "eco homes" were built in our village about 5 years ago. Thick walls, triple glazing, the lot. When it snowed heavily two winters ago, the solar heating panels worked backwards, all the snow on their roofs melted as heat exited the building.

[dennis]

Are you sure it melted and didn't fall off due to slippery surfaces?

[Dave Liquorice]

Not quite sure what you mean. Solar thermal panels? The *whole* roof?

Whole roof sounds like they missed out the roof insulation. Just the solar thermal panels; incorrect setup or installation. Most solar thermal controllers have a frost protection setting for use in places where frosts are rare so the cost of antifreeze in the circulating water isn't justified. In the UK that doesn't apply and you put in antifreeze and turn off the frost protection...

[tim.....]

Whilst logically the correct explanation I don't think that gas is the base fuel used here

tim

[Dave Liquorice]

Agreed, space heating isn't mentioned only hot water heated from recovering the waste heat in exhaust air from the building. This implies= that the building occupied normally doesn't need any space heating, ie i= s very well insulated.

Looks more like the housing assoc's have been sold a pup. The figures do= more or less work out. 550W 24/7 for a year is 4818 kWHr. 10p/unit near =

enough their quoted =A3500/year running cost. Of course that doesn't include *any* other electrical use which could easyily be another 5000 kWHr... bring the total bill to around =A31000/year.

Aye, if a place doesn't need any extra space heating recovering the wast= e heat in the exhaust air seems emminently sensible. 1kW 24/7 is enough to= keep a decent sized thermal store well hot. Yes a succession of baths will cool it and bring in the backup (expensive) immersion heater. So there also needs to be a change in habits, stagger bath nights through the week for each family member. Rather than everyone having a bath on Sunday night. Have a shower in preference to a bath.