UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

Ecomarster

Everybody who is looking to get an air source heat pump I would advise to look at *********website, they provide a free survey for your house and service is great. We had a heat pump installed in our house last year,best decision ever!

Taken out name of my heat pump. Being accused of spam!

zeupater

Ecomarster wrote: »

Everybody who is looking to get an air source heat pump I would advise to look at husky heat pumps website, they provide a free survey for your house and service is great. We had a heat pump installed in our house last year,best decision ever!

Hi Ecomarster

Considering the content of a first post, hopefully it's not spam, so welcome to the forum

Can you provide readers with further details of your installation and how it performed over last winter, including the extreme cold spells.

Z

Ecomarster

Installed last summer, according to *********, our heat loss was 8.1kw.They installed a 13kw unit.During the winter we had no problems because as a part of the after service we were actually told how to get the best out of our heat pump.One piece of advice was to use the heat pump when it's warmer,ie during day time.So even when we had low temperatures(-15 where I live)heat pump was able to provide enough heat during day time and sort of hold the temperature during night.We never had a problem, we have an aux heater built in but never needed to switch it on.We also have our condensing gas boiler fitted in line should we need it, which we havnt. Costs to run- 20% less then previous year.That is not much but against a high efficiency condensing gas boiler, it's not bad.

And no, this isn't spam. Sorry I can't be a little more technical on how it's installed.

Cardew

Ecomarster wrote: »

During the winter we had no problems because as a part of the after service we were actually told how to get the best out of our heat pump.One piece of advice was to use the heat pump when it's warmer,ie during day time.So even when we had low temperatures(-15 where I live)heat pump was able to provide enough heat during day time and sort of hold the temperature during night.We never had a problem, we have an aux heater built in but never needed to switch it on.We also have our condensing gas boiler fitted in line should we need it, which we havnt. Costs to run- 20% less then previous year.That is not much but against a high efficiency condensing gas boiler, it's not bad.

And no, this isn't spam. Sorry I can't be a little more technical on how it's installed.

Firstly you are(no doubt inadvertently) describing a feature that is one of the major drawbacks of heat pumps.

People who are out at work, or away from the house, don't want to have the expense of having to heat the house during the day when they are not present. This is required with an ASHP because of the low output is not sufficient to quickly heat up a house; especially if you want to heat hot water as well.

Gas CH can heat water to 80+C and warm up houses quickly - an ASHP with water at 35C-40C(for maximum efficiency) simply can't.

I am also interested in your view that the cost to run was 20% less than last year when using a high efficiency gas bolier. I would be interested to know how you calculated that figure?

As far as I am aware, no independant organisation, -WHICH Energy Saving Trust(EST) etc - states that an ASHP is cheaper than Gas CH, or recommends fiiting an ASHP if gas is available as gas is always cheaper.

The EST did a field trial over a year of lots of heat pump systems, with manufacurers involved, and not one was as cheap as gas - and that is without considering the drawback mentioned above. Many results were frankly little short of a disaster.

I am interested that you keep a gas boiler 'in line' with your ASHP. Do you have radiators or underfloor heating? If the former you surely must have increased the size of the radiators?

Why would you ever contemplate using an aux heater when you have gas back-up?

Ecomarster

Firstly, I'm actually at home most days so the reality is I need my heating on. Secondly if I did go out for the day, I would only need to put the heating on 2 hrs before coming home for the house to be up to temperature, hardly a disaster.

I was not aware of the EST report but ive now had a good read. It seems you omit to mention a key point. Out of all of the poorly performing heat pumps, it was down to poor installation that caused the poor results. This is hardly the heat pumps fault is it? The actual problem !seems to involve multiple contractors. Also mentioned was air source heat pumps are proven technology in Europe and that a single supply and install chain like they have in Europe was best. So the reality is that our installers have not quite got to grips with installation yet and fault should not be apportioned to heat pumps.

In regard to my bill, well that one is fairly easy, If I add my combined expenditure for gas and electric for the last 12 months and compare that to the previous 12 months, I paid 20% less. Of course it may have been a warmer winter this year, I don't know. I could go into fine detail of why a good heat pump coupled with a good install should in fact would out perform a gas boiler during an average uk winter.

It seems that unlike in Europe, the uk we are slow to embrace heat pump technology. In fact I would almost suggest there is a vendetta against them, probably from the gas community for obvious reasons. I'm very happy with mine and I know others are happy with theirs. !

Cardew

Ecomarster wrote: »

Firstly, I'm actually at home most days so the reality is I need my heating on. Secondly if I did go out for the day, I would only need to put the heating on 2 hrs before coming home for the house to be up to temperature, hardly a disaster.

I was not aware of the EST report but ive now had a good read. It seems you omit to mention a key point. Out of all of the poorly performing heat pumps, it was down to poor installation that caused the poor results. This is hardly the heat pumps fault is it? The actual problem !seems to involve multiple contractors. Also mentioned was air source heat pumps are proven technology in Europe and that a single supply and install chain like they have in Europe was best. So the reality is that our installers have not quite got to grips with installation yet and fault should not be apportioned to heat pumps.

In regard to my bill, well that one is fairly easy, If I add my combined expenditure for gas and electric for the last 12 months and compare that to the previous 12 months, I paid 20% less. Of course it may have been a warmer winter this year, I don't know. I could go into fine detail of why a good heat pump coupled with a good install should in fact would out perform a gas boiler during an average uk winter.

It seems that unlike in Europe, the uk we are slow to embrace heat pump technology. In fact I would almost suggest there is a vendetta against them, probably from the gas community for obvious reasons. I'm very happy with mine and I know others are happy with theirs. !

Forgive me if I am a little sceptical about your posts on here!

In your earlier post you state:

And no, this isn't spam. Sorry I can't be a little more technical on how it's installed.

Now you state:

I could go into fine detail of why a good heat pump coupled with a good install should in fact would out perform a gas boiler during an average uk winter.

'Can't be a little more technical' at first, but then have the ability to go into fine detail smacks of someone with a vested interest; especially as your first post advises us to look a ***** heat pumps web site.

That is reinforced by your totally incorrect conclusions drawn from the EST report.

http://www.energysavingtrust.org.uk/Media/node_1422/Getting-warmer-a-field-trial-of-heat-pumps-PDF

Why would 'poor insulation' cause poor results when the results are given as the overall COP of the system?

Where does it say 'multiple contractors' are a contributing factor?

The whole point of a year long trial is to establish the overall COP of the ASHP system. If the system draws x kWh and produces 2x kWh it has an overall COP of 2.0.

Could you be getting confused; in that for ASHPs to be effective for space heating, good insulation is essential. Of course we then have to consider heating domestic hot water, which is hardly the strong suite of an ASHP.

Nobody is disputing that ASHPs should deliver better performance, but from the many customer horror stories and results of the EST trial, it is obvious that this isn't being achieved. This despite the involvement of all the major heat pump manufacturers in the trial. I suppose 'your' firm will do better;)

As for your statement that an ASHP can out perform a high efficiency gas CH system, perhaps you can point out any independent authority that agrees with you? (WHICH, EST etc)

Similarly your calculations on how you achieved a 20% saving on bills don't stand up to scrutiny.

Ecomarster

Actually you misread my post. It's not poor insulation, it's poor installation!!

You can actually think what you like regarding my posts being spam. It doesn't bother me inn the slightest. I see you are a figurehead on here with over 15,000 posts. Wow! You must really be the authority. I don't often get involved in forums anyway. I'm having solar panels fitted next week. I suppose if I mention the company's name, I work for them too! The reality is, I'm all for renewable energy and looking after our climate.

Having been quite attacked by yourself, I will step aside with no further posts. But as a final note, I see in many of your other posts you seem to go on the offensive about ashp. Gas engineer by any chance? Anyway I hope you enjoy your next 15,000 posts like you did the first. Good luck!

Ps. Taken out name of my heat pump. People will have to shop around themselves.

Edale

We have just had our first week with our new Mitsubishi Ecodan ASHP so I thought I would give a report.

I looked at lots of information both good and bad on here and elsewhere before deciding that it was an option as long as the system was properly specified, our house was built in the late 60s has cavity wall insulation, double glazing throughout and good levels of loft insulation. Previous heating system was oil fired and the boiler was c25 years old and making strange noised, I had paid 70p per litre for the last fill and from end of October to mid March had used an average of 90 litres per week. The radiators only ran at 60C so I felt the lower temperature of the Ecodan should be sufficient.

We have the 14KW version and including a new unvented 300 litre cylinder and 3 new radiators cost just over £9K after the CERT funding has been deducted. A new oil boiler and cylinder would have cost in the region of £4K. Without RHI I felt the decision would be marginal financially, so I was disappointed when they weren't included last week, however I think they will be included in 2012 and this has appeared on the DECC website suggesting they will include them.

We have had a couple of frosts this week and I think the house is warmer than before, our hot water is definitely warmer. I have checked our electricity usage and in total we have used 263KWH from 8.30am last saturday to 8.30am this saturday which is about £22, this includes all other use (cooking, washing, tumble drier, lights tv etc). I have no doubt if we had fitted a new oil boiler it would have been much more efficient but think it would cost much more than this.

If they had anounced RHI even at half the previously proposed levels (7.5P per KWH) I would have been very happy. As it is I am still happy with the decision to fit the ASHP and any future RHI will make it a very good financial decision.

We still have to see how it performs in the extreme cold and I intend to fit a log burner as a backup just in case and to protect against powercuts.

I have no axe to grind and if I felt I had made a bad decision I would say so, when I decided to have it fitted I did feel there was a risk it wouldn't be effective but felt the oil companies ripped me off in December, this was a big motivator for me.

All in all I am very happy with the performance and running costs so far, if anyone wants to see it working I live near Worksop and would be happy to show you it. I am also happy to give any other feedback on it and will even enter into dialogue with Cardew, before you start I have no connection whatsoever to Mitsubishi or the ASHP industry.

lovesgshp

To Ecormaster.

If your heating requirement was only 8Kwh, why did they install a 12Kw unit? That is 30% oversized, so is not working at peak efficiency, plus using more power to run.

You do not say whether you are using radiators or underfloor heating so the 2 hr reheat time is suspect. With a system off, then normal stabilised temps are circa 24 hrs. What are your internal heating settings?

Cardew

Edale wrote: »

All in all I am very happy with the performance and running costs so far, if anyone wants to see it working I live near Worksop and would be happy to show you it. I am also happy to give any other feedback on it and will even enter into dialogue with Cardew, before you start I have no connection whatsoever to Mitsubishi or the ASHP industry.

Hi Edale,
Nice well considered post – I hope that doesn’t sound condescending!

I am very conscious of being cast in the role of the ‘ASHP opponent’ because of the reservations I have expressed about the systems.

I felt that threads on Heat Pumps on MSE were being dominated by enthusiasts and posters with a commercial vested interest in promoting the technology; and felt that the impression was being given that ASHPs were a no brainer; and IMO they ain’t.

People are being sold systems where COPs of 4 or even 4.5 are quoted and it is implied that these figures are what you can expect “for every electricity unit you get out four units of heat.”

The EST field trial results put that firmly into perspective, and everyone must concede the results were little short of a disaster.

Particularly irritating are posts like that from Ecomarster above who claim that their system is 20% cheaper than a high efficiency gas CH system. He gives no detail and gets his 20% from the following calculation:

If I add my combined expenditure for gas and electric for the last 12 months and compare that to the previous 12 months, I paid 20% less.

That is a 20% reduction on his overall gas and electricity bill. So as his normal electricity consumption would not be affected, it means that his ASHP provides heating and hot water for something like 30% to 40% cheaper than gas! If you take into account that last year was much colder than the previous year, and electricity prices have increased, his claims are even more unbelievable!

When challenged, he gets in a huff and disappears.

Anyway back to your system, some questions if I may(and play the Devil’s advocate!)

How will RHI be able to award a subsidy of xp/kWh. i.e how will it be measured.

You are frugal and have the temperature in the house at, say, 15C. In an identical house I have mine at 26C day and night and use twice as much electricity as you; so do I get twice the subsidy?

You have paid £5k more than for a new oil CH system. Given you could invest that £5k in a long term investment at 5%, that would produce £250 a year(£200 after tax) – how long do you envisage it will take before you have recouped that £5k?