Air Source Heat Pumps/Air Con - Full Info & G...

[TiredGeek]

They've even fitted the condensate tray! Nice

[jeepjunkie]

Great to see the pics.

https://dl.dropbox.com/u/7521506/PA190118.jpg

[nande2000]

Doh ! The lockshield valve was shut on the rad I had problems with; house now piping hot everywhere. All we need now is some really cold weather to test the system to its limit.

[TiredGeek]

Originally Posted by nande2000

Doh ! The lockshield valve was shut on the rad I had problems with; house now piping hot everywhere. All we need now is some really cold weather to test the system to its limit.

Well that's a relief
Glad it was something so simple...

[nande2000]

Interestingly the guy that installed mine was telling me he installed an Ecodan 8.5kw for his own house, then upgraded his insulation and downsized to the 5kw model. It heated his house fine but the electric consumption went up by 50%, so hes putting his 8.5 back in.

[jeepjunkie]

As you can see from the pics below the ASHP going through a defrost. Not that you'd notice it inside as house very warm. Tis a bit chilly here with snow on the ground.

https://dl.dropbox.com/u/7521506/PC050686.JPG

https://dl.dropbox.com/u/7521506/PC050687.JPG

[John_Pierpoint]

Originally Posted by jeepjunkie

Great to see the pics.

https://dl.dropbox.com/u/7521506/PA190118.jpg

I am a bit confused about the relationship between this photo and these

Originally Posted by jeepjunkie

ASHP going through a defrost.

https://dl.dropbox.com/u/7521506/PC050686.JPG

https://dl.dropbox.com/u/7521506/PC050687.JPG

[albyota]

Originally Posted by John_Pierpoint

I am a bit confused about the relationship between this photo and these

John_Pierpoint, The first phot just shows the 14kW Ecodan looking at the front of the unit, The other two photos show the frosting occurring on the rear of the coil (two angles) and by the look of it, at night.

JJ will confirm

Al

[Diallingtone]

Hi all - I've joined MSE just so I can participate in this thread! I had an Ecodan installed back in August; an 8.5KW unit for my 3 bed house.

I was nervous - not least because of the heated debates elsewhere in these forums about ASHP efficiencies and associated horror stories. Reading all those posts from Cardew about how it was all doomed to failure

Anyway, I think my Ecodan is..... FANTASTIC!

Hot water has never been hotter - we are boosting via immersion much less, maybe 3 times in 6 months versus a few times per week before. Inside temp is absolutely fine, even when we've got down to -5º outside.

I've checked with the neighbours and they don't hear it - which was a concern - but to be honest it's less noisy than my rattly old LPG boiler. If you walk down our street at night, you can hear the heating going in most houses - mostly boilers venting outside. The Ecodan makes a different kind of noise, but in truth it's not any more intrusive.

The defrost cycle is amazing. Last night, I was looking at the unit and it's all frozen up - looks like the inside of a fridge. Then the unit makes a noise a bit like a lorry's air-brakes and, after a few moments, the ice turns clear and starts to run off as water into the soakaway.

I explain to people that it works by combining electricity with some clever gubbins and a pinch of pixie dust - no other rational explanation

ASHPs aren't perfect. Because the rads don't get as hot, it does take longer to get a house up to temperature - so we have the heating on all the time and keep it in a fairly narrow range; 16º overnight, 19º during the day and 21º at night. In my experience, it can take an hour to raise the temp by 1º - not a problem per se, you just have to plan a bit better.

I still can't comment on running costs. Back in August we were nearly £300 in credit with SSE and probably over paying by £20-30 per month. It will take a while to burn through that and assess increased payments. With Solar PV and Solar Thermal and no separate usage meter for the ASHP, I have no way of tracking what it uses with any confidence. No matter. I'm sure it's cheaper than LPG and every time I see that my LPG tank has gone, I still smile!

When the RHI payments kick in next year, I will hopefully get some dosh which will speed up the return on investment and be the proverbial cherry on the cake.

So far so good. Although I don't like the cold weather, I am secretly wanting the temperature to drop even further so I can see how well it works. Rated down to -15º, I think the coldest we've recorded round here is around -11º, so it should be interesting.

[jeepjunkie]

Originally Posted by Diallingtone

Hi all - I've joined MSE just so I can participate in this thread! I had an Ecodan installed back in August; an 8.5KW unit for my 3 bed house.

I was nervous - not least because of the heated debates elsewhere in these forums about ASHP efficiencies and associated horror stories. Reading all those posts from Cardew about how it was all doomed to failure

Anyway, I think my Ecodan is..... FANTASTIC!

Hot water has never been hotter - we are boosting via immersion much less, maybe 3 times in 6 months versus a few times per week before. Inside temp is absolutely fine, even when we've got down to -5º outside.

I've checked with the neighbours and they don't hear it - which was a concern - but to be honest it's less noisy than my rattly old LPG boiler. If you walk down our street at night, you can hear the heating going in most houses - mostly boilers venting outside. The Ecodan makes a different kind of noise, but in truth it's not any more intrusive.

The defrost cycle is amazing. Last night, I was looking at the unit and it's all frozen up - looks like the inside of a fridge. Then the unit makes a noise a bit like a lorry's air-brakes and, after a few moments, the ice turns clear and starts to run off as water into the soakaway.

I explain to people that it works by combining electricity with some clever gubbins and a pinch of pixie dust - no other rational explanation

ASHPs aren't perfect. Because the rads don't get as hot, it does take longer to get a house up to temperature - so we have the heating on all the time and keep it in a fairly narrow range; 16º overnight, 19º during the day and 21º at night. In my experience, it can take an hour to raise the temp by 1º - not a problem per se, you just have to plan a bit better.

I still can't comment on running costs. Back in August we were nearly £300 in credit with SSE and probably over paying by £20-30 per month. It will take a while to burn through that and assess increased payments. With Solar PV and Solar Thermal and no separate usage meter for the ASHP, I have no way of tracking what it uses with any confidence. No matter. I'm sure it's cheaper than LPG and every time I see that my LPG tank has gone, I still smile!

When the RHI payments kick in next year, I will hopefully get some dosh which will speed up the return on investment and be the proverbial cherry on the cake.

So far so good. Although I don't like the cold weather, I am secretly wanting the temperature to drop even further so I can see how well it works. Rated down to -15º, I think the coldest we've recorded round here is around -11º, so it should be interesting.

Great to hear another success story.

I suppose if it were not for blokes like Cardew we not do as much research as we do prior to install.

Cheers

[Cardew]

Originally Posted by Diallingtone

I was nervous - not least because of the heated debates elsewhere in these forums about ASHP efficiencies and associated horror stories. Reading all those posts from Cardew about how it was all doomed to failure

Anyway, I think my Ecodan is..... FANTASTIC!

Welcome to the forum.

I appreciate that your comment is 'tongue in cheek', but there shouldn't have to be any horror stories when people pay??(£10,000+?) for a system.

It is quite obvious that ASHPs can work well, but all too often they don't, as the horror stories on MSE(with ripped out ASHPs) and elsewhere on the web illustrate - not to mention the Energy Saving Trust 12 month trial which was IMO little short of a disaster - and no follow up report to show things have improved.

I believe that the manufacturer should take responsibility their systems and not pass the buck to the installers. If your house was unsuitable for an ASHP because of insulation deficiencies, I wonder how many installation firms would have told you and lost the opportunity to do business.

There is one other very important point, that is an inherent disadvantage of ASHPs, that you mention in your post:

ASHPs aren't perfect. Because the rads don't get as hot, it does take longer to
get a house up to temperature - so we have the heating on all the time and keep
it in a fairly narrow range; 16º overnight, 19º during the day and 21º at night.
In my experience, it can take an hour to raise the temp by 1º - not a problem
per se, you just have to plan a bit better.

For an ASHP to be effective you have to run it like you do - i.e. running 24/7. That is a big disadvantage, particularly for people out at work all day. Someone who is at work, say from 8am to 6pm is having electricity consumed and heat produced for an empty house - wasted enrgy and costs. With conventional CH it is sufficient to have it timed to come on, say, 30 mins before returning to the house.

Many prospective customers are unaware of the above and I have never seen this issue given publicity.

Anyway it looks like you have got a good system! Let us hope the running costs are low.

P.S.
Do you mind saying how much your system cost - and did you have to get new/extra radiators?

[Diallingtone]

So, my installation consisted of:
8.5KW Ecodan
New 200L water tank (at my request) - up from 140L
4 new rads; 2 in lounge, 1 in kitchen, 1 in main bedrooom
Plus, 1 rad moved from lounge to bedroom 2
New thermostatic valves on all rads
decommissioning of old boiler & make good

Total cost: £7,500 (net of grants - £850 from DECC and £400 from Mitsubishi)

I was paying £125 per month to Calor for LPG - just for heating, hot water was done by immersion heater. My installer estimates annual running costs for heating and hot water to be £550 (based on the heat loss estimate), so if that's true, a big annual saving on the £1500+ I was paying before. Only time will tell. On that basis, payback of around 7 years at current prices, albeit the RHI payments next year should make that much more attractive, hopefully payback in less than 5 years.

My lounge has a vaulted ceiling which takes longer to heat - the 1º per hour may vary by property type, but it is evident the rads don't get as hot - max temp would be 50º versus 70-80º (I would guess) for gas.

If the heating is on all day, the impact is relevant only to total resources consumed, i.e. if it's still cheaper to have ASHP on all day versus timed oil/gas, I guess that's a good outcome. ASHP have lower CO2 output, plus (and I like this spin off) it takes heat from the air, so in its own way it fights global warming

Early days, but I'm pleased to be free from LPG, especially since I offset the electric with solar PV and will do more as and when new opportunities (Ridgeblade?) come along.

[zeupater]

Originally Posted by Diallingtone

....., plus (and I like this spin off) it takes heat from the air, so in its own way it fights global warming .....

.... Apart from the issue that the heat that has been pumped inside leaks back out through the walls, windows, roof etc ....

... funny, but I've heard that particular argument used before, it's a bit like saying that leaving the freezer door open in the summer cools the kitchen ....

Z

[Cardew]

Originally Posted by Diallingtone

My lounge has a vaulted ceiling which takes longer to heat - the 1º per hour may vary by property type, but it is evident the rads don't get as hot - max temp would be 50º versus 70-80º (I would guess) for gas.

If the heating is on all day, the impact is relevant only to total resources consumed, i.e. if it's still cheaper to have ASHP on all day versus timed oil/gas, I guess that's a good outcome. ASHP have lower CO2 output, plus (and I like this spin off) it takes heat from the air, so in its own way it fights global warming

Early days, but I'm pleased to be free from LPG, especially since I offset the electric with solar PV and will do more as and when new opportunities (Ridgeblade?) come along.

Thank you.
The maximum CH water temperature for most gas boilers is 82C I believe.

Whilst the maximum temp of CH water(not HW) from your ASHP is 50C, surely you wouldn't normally run it at that temperature?

[grahamc2003]

Originally Posted by zeupater

.... Apart from the issue that the heat that has been pumped inside leaks back out through the walls, windows, roof etc ....

... funny, but I've heard that particular argument used before, it's a bit like saying that leaving the freezer door open in the summer cools the kitchen ....

Z

Sort of.

But the heatpump gives say 100kwh of heat inside for about 35kWh of electricity, whereas a gas boiler gives 100kWh of heat inside by burning about 110kWh of gas.

Yes, the heat sucked from the outside leaks back outside along with an extra dollop amounting to about 1/3rd, but with alternative heating, an extra whole dollop is leaked to the outside.

Or put yet another way, the atmosphere is heated by 110kwh for each 100kwh of home heating by gas, whereas for a heat pump, the atmosphere is only heated by 35kwh.

(Not that I think that matters).

[grahamc2003]

Originally Posted by Diallingtone

The defrost cycle is amazing. Last night, I was looking at the unit and it's all frozen up - looks like the inside of a fridge. Then the unit makes a noise a bit like a lorry's air-brakes and, after a few moments, the ice turns clear and starts to run off as water into the soakaway.

I:

Good to hear owner's views on these.

Yours seems very cheap compared to my quotes (about £12k/£13k for a 14kW, including new wet system). Wouldn't mind a quote from your installers, if you would care to divulge (either on the board or by pm).

Shame you didn't have any meters fitted. Although the defrost obviously works fine, I'd also like to know the cost of a defrost, and how often it occured at various temperatures. Not sure if Mitsi offer such metering, or whether it's available from third parties (or whether to make do with an inaccurate Owl).

Very useful info regarding noise etc, thanks.

[nande2000]

Must admit Im amazed at how good my Ecodan is at heating HW (i was bracing myself for the wife moaning about washing the dishes cold) - It is miles better than the oil range cooker/boiler it replaced.
The water temp gets up to 60 degc in a 210 litre tank in the same time it took the oil range to heat a 120l tank.

Personally I think heat pumps would work for any property (within reason), just the installer has to plan the extra rads and insulation for you. With fossil fuel boilers bad installers could cover their tracks by oversizing.

Got mine (8.5kw Ecodan + 210litre vented thermal store plus one new 1800mm wide rad) installed for £7200 inc vat and I havent had my RHPP yet. Its not that far off what a new external oil boiler would have cost me (inc cost of a new tank)

When you buy a new heating system of any sort you need to assume that most installers have no clue in what they are doing..In my limited experience about 60% are charlatans.

Originally Posted by Cardew

Thank you.
The maximum CH water temperature for most gas boilers is 82C I believe.

Whilst the maximum temp of CH water(not HW) from your ASHP is 50C, surely you wouldn't normally run it at that temperature?

[lovesgshp]

Originally Posted by Cardew

Thank you.
The maximum CH water temperature for most gas boilers is 82C I believe.

Whilst the maximum temp of CH water(not HW) from your ASHP is 50C, surely you wouldn't normally run it at that temperature?

We have systems working on the 50C rad output temperature and the clients say that the temperature in the room is more stable and comfortable, as constant against when they had gas.

[Mister G]

Originally Posted by grahamc2003

Sort of.

But the heatpump gives say 100kwh of heat inside for about 35kWh of electricity, whereas a gas boiler gives 100kWh of heat inside by burning about 110kWh of gas.

Yes, the heat sucked from the outside leaks back outside along with an extra dollop amounting to about 1/3rd, but with alternative heating, an extra whole dollop is leaked to the outside.

Or put yet another way, the atmosphere is heated by 110kwh for each 100kwh of home heating by gas, whereas for a heat pump, the atmosphere is only heated by 35kwh.

(Not that I think that matters).

Ah, but what about the CO2 footprint of the power station that generates that 35kWh?

[Cardew]

Originally Posted by Geotherm

We have systems working on the 50C rad output temperature and the clients say that the temperature in the room is more stable and comfortable, as constant against when they had gas.

I can't see why that would be the case when they could have their gas boiler water temperature set to 50%

My point was that running an ASHP to give a water temperature of 50C gives a lower COP than, say, 35C.This is why heat pumps are so suited to under floor heating.

It is also a fact that some(not all by any means) people who have paid good money for a product, are less inclined to be objective in their appraisal of that product.. Even on MSE tenants(both council/HOA and private) generally are more critical of heat pumps.

I speak as someone who bought 2 Betamax VCRs and a Toshiba HD DVD player - convinced that VHS and Blu-ray wouldn't catch on!