heat pumps - real life experiences?

sunnysoutheast

Hello all;

We've been following a few threads on here regarding the pros and cons of geothermal heat pumps - does anyone have some real-life experiences they can share - install cost, running cost, comfort, etc.?

The background is that we're in the initial stages of a new build and we're approaching decision time on heating/DHW. We'd like to go down the sustainable route but the prices we're being quoted for heat pumps seem very high - making the payback period vs. a high-efficiency condensing gas boiler very long. We've already upspecced all insulation, ordered uValue=1.1 windows and plan to install heat recovery ventilation.

We're happy to share our experiences going forward, be great to hear any war stories you have.

(post redone as it failed the first time - grrr!)

iplogger1

sunnysoutheast wrote:

Hello all;

We've been following a few threads on here regarding the pros and cons of geothermal heat pumps - does anyone have some real-life experiences they can share - install cost, running cost, comfort, etc.?

The background is that we're in the initial stages of a new build and we're approaching decision time on heating/DHW. We'd like to go down the sustainable route but the prices we're being quoted for heat pumps seem very high - making the payback period vs. a high-efficiency condensing gas boiler very long. We've already upspecced all insulation, ordered uValue=1.1 windows and plan to install heat recovery ventilation.

We're happy to share our experiences going forward, be great to hear any war stories you have.

(post redone as it failed the first time - grrr!)

Hi SunnySouthEast , rainWest here

Check this thread (and see qwerty's contribution.. scroll down)
I am in same boat. I'm strongly considering heat pump for
a 2700 sq ft (250 sq mtr) 2 storey house in the West.

Qwerty's figures are encouraging given the size of his family
living area and he is keeping a very good account of the
monthly costs to date, etc.

~ipl

iplogger1

iplogger1 wrote:

Hi SunnySouthEast , rainWest here

Check this thread (and see qwerty's contribution.. scroll down)
I am in same boat. I'm strongly considering heat pump for
a 2700 sq ft (250 sq mtr) 2 storey house in the West.

Qwerty's figures are encouraging given the size of his family
living area and he is keeping a very good account of the
monthly costs to date, etc.

~ipl

oops .. the link to the thread I felt you ought to check in the boards.ie
archives is

http://www.boards.ie/vbulletin/showthread.php?t=2054905421&referrerid=59211&highlight=heat+pump+night%22

Viking House

Remember if you are drylining or putting insulation in the cavity
"these systems never give what it says on the tin"
In tests these houses loose twice as much heat as the literature suggests.

The Viking Timber Frame 2500ft2 house costs €23/month to heat in Finland.

Do-more

Have you considered an air-source heatpump? Much lower capital cost than ground source and with a €4000 grant available for air source your net outlay will be very small, meaning a much quicker payback than for ground source. No digging either! Also idea for someone with a small plot. Perennial problem for heatpumps in this country is the heat distribution system. Underfloor heating is fine in Scandinavia where they have nice stable weather, but in this country where we can have "four seasons in one day" the 3 hour time delay in heating your floor slab makes room stats a nonsense, rads are no good at the 50C water temps that heat pumps produce. From my research for my next build I will go with an Airsource heatpump and Solo fan convectors from this crowd, www.lowenergy.ie anybody I have spoken to that has Solo's, rave about them. The old design was a bit poxy looking but they now have really sleak looking new ones.

Enquired about wood pellet boilers the other day and apart from the rip-off prices (detailed in some other threads) it's maintenance issues and fire risk hazards that worry me. e.g. you get called away in the middle of topping up the hopper and don't close the lid, the next time the boiler fires up you could get fire back up into the hopper! Not a good prospect. Burners need to be cleaned regularly to maintain efficency. Augers need to be changed every 5 years or so. All seems like too much risk and trouble for me.

Yes electricity prices are liable to rise with oil prices, but if we every get our act together in this country with more wind and wave power the relationship will be less direct.

My 2 cents worth for today!

anon1

Real life experiences posted on the Solo fan convectors would be great.

yop

I will sort out figures for you over the weekend, we have it in now since Feb in a 2100 sq ft Timber frame with loads and loads of insulation and UFH.

Do-More - Would not recommend an ASHP. Do a search on boards for a number of threads stating why these are regarded as the least efficent of the heatpumps. I have a mate who has one in and is now contemplating getting rid of it. Yes they are fine if you are stuck for space but if you are not I would look at aternatives.
The secret to UFH working better is a smaller loop and a thinner screed. They are still slow to react but if you have a outdoor heat sensor on your HP this will aid.
UFH is recommended to be used with heatpumps due to its lower running temp but I do hear that them rads are a good alternative, but they need electricical source so therefore cost you more.
But hey everyone has their preferences.

tribesman

Do-more wrote:

Underfloor heating is fine in Scandinavia where they have nice stable weather, but in this country where we can have "four seasons in one day" the 3 hour time delay in heating your floor slab makes room stats a nonsense,

If your insulation is adequate then your house won't heat up or cool down rapidly depending on whether the sun goes in our out.

I have a GSHP with UFH. I run it almost exclusively at night on night rate electricity. I find that I can heat the rooms to a comfortable temperature at night and that this temperature will be maintained during the day without any top-up.

The only instance where the response time is an issue is when there is a very sunny day after a very cold night. The heatpump puts a lot of heat into the floor and then the sun heats the room further during the day. This can result in a slight overheating of the south facing rooms and sometimes necessitates opening windows.

I should add that I have about 50% more insulation than required by the current building regs. I'm sure that this helps maintain the temperature during the day.

Do-more

Thanks for the comments folks, my parents have UFH in well insulated new house but their living room has a large picture window to take advantage of the views and often overheats on a sunny day even in the middle of winter.

Surprised to find that so many are negative on Air source. My in-laws have air-to-air system in Sweden and it is very effective for them and I would have thought that efficency should be better here with higher ambient temps and RH?

Do-more

Yop - I just spent the last hour and a bit reading the boards and it has been enlightening! Whilst I accept that Nordic has his own commercial interests at heart his arguments for well water source heat pumps are pretty convincing (Unless anyone knowns different?)

Still not convinced on UFH though, my parents example together with too many stories about bad installations make me very wary.

At the end of the day I guess the priority is to spend the money on insulation, a completely airtight home with heat recovery ventilation and the result should be low heating costs regardless.

yop

Aye, the Borehole is definately your most efficent type of alternative energy with a heatpump. The issues seems to be costs, I was looking @4k more for the borehole than the ground loop.

I totally agree about insulation, over insulate as much as you can, wrap it like a sleeping bag and it will cost u little to heat.

Best of luck with it anyway and please ask if u need more info

sunnysoutheast

Thanks everyone - not surprised to see that a lot of people are in a similar quandary to us

the main concerns we have around heat pumps are a) the very high capital cost, particularly on borrowed money b) the ongoing support issues - who knows which vendors/distributors will be around in, say, three years if you have a component failure. AFAIK all of the pumps themselves are imported from Sweden, France, Germany, etc.

I think the key to this is to over-insulate and keep whatever heat you've generated inside - that investment should pay for itself relatively soon whatever route you take. We've tried to do this already.

Luckily we don't need to confirm everything until towards the end of this year - we're looking at solar for hot water too - but that brings its own challenges in terms of integrating control systems etc.