Heat Pump for heating water

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Angies

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Does anybody with a geothermal heat pump use it for heating their water or do you use another source - emmersion, solar panels etc. Just wondering is it actually an efficient way of doing it if the heat pump is on anyway for underfloor heating. Thanks
 
We installed an air to water heat pump with UFH recently in our new house. In our case, the heat pump (house aprox. 2900sq ft - heat pump is 12kw) heats all hot water.

I asked the plumber at the time if he thought it was worthwhile for us to consider solar pannels, his opinion was that the it costs so little for the heat pump to do it that solar panels wouldn't be cost effective.

Havn't calculated specifically what the cost the hot water only aspect is to date, but something I should do.
 
dj01 said:
We installed an air to water heat pump with UFH recently in our new house. In our case, the heat pump (house aprox. 2900sq ft - heat pump is 12kw) heats all hot water. ...................
Click to expand...

That sounds useful

What temperature does it heat the HW to ?
 
dj01 said:
We installed an air to water heat pump with UFH recently in our new house. In our case, the heat pump (house aprox. 2900sq ft - heat pump is 12kw) heats all hot water.

I asked the plumber at the time if he thought it was worthwhile for us to consider solar pannels, his opinion was that the it costs so little for the heat pump to do it that solar panels wouldn't be cost effective.

Havn't calculated specifically what the cost the hot water only aspect is to date, but something I should do.
Click to expand...


thats strange, it is usually the other way around!
 
I heat the house and all water using a ground-source heat pump. My electicity bill for the year is about 2k (180 sq m house) with, based on fast and loose calculations on the hours active, heating costing 900 euro a year and water about 400. The heating is on from October to April. That's bringing the water to about 55 degrees C. If you want it hotter, you'd spend a bit more...
 
Thanks for that. We were heating our water with the heat pump but then tried out the emmersion and funnily enough our ESB wentsky high! So i think i will be switching back.
 
DJO1 do you mind me asking what sort of heat pump are you using & what are your bills like so far ?
 
It's a Thermia Atria (link below). Since we moved into the house in early August the total electricity cost is 1400, so hoping the full year will come in around 2k. That's heating on since August and all other electricity usage included.

Can take a while for bills to regulate as it takes a fair amount of time to get the temperature setttings and timings set to what suits you. The pump heats the water to aprox. 50 deg.

[broken link removed]
 
Thanks dj01, really appreciate the response. Its so hard to speak to anyone with direct experience of air to water heat pumps. I would be very grateful if you would respond to the following queries:
1. Does the heat pump stop functioning at 0 degrees & if so is heating your home with the element not very costly ?
2.Do you have to leave the heat on all the time ? & just turn the temp down very low on warm days or can you turn it on & off as required ?
3. Can you have heat in indivdual rooms & turned off in other rooms ?
4. If you were building again would you go with a heat pump or a more traditional heating system ?
Would greatly appreciate a response as nearly at decision time.
 
No problem, found the same thing myself when we were researching options.

1) You can set a 'heat stop' temperature that when a specified outdoor temperature is reached heat production stops. Done via an external thermostat fixed on the north facing wall of the house
2) To turn off you can just set a low heat stop temperature. There's also two programmable temp settings which are set via a programmable timer. Generally you set a lower constant temp e.g 15 degrees and then a higher temp that you may want to increase to at night for example (e.g. if you are using a day/night meter you may want to build up heat in the house during the night at the lower rate of electricity)
3) You can lower the heat in rooms where thermostats have been installed, but you cannot 'call' a higher temp than the heat pump is outputting
4) looking at the running costs currenlty, i would definately investigate all options. Would put in a stove with a back boiler, and then a secondary heating system of some kind, maybe high efficiency gas condesning boiler. I would also install a Heat recovery ventialtion unit to maximise the use of the heat being generated. There was an artile some time ago on aam about a products called Turbo Stove - don't know alot about it but looked interesting - they have a website [broken link removed] The best advise through is insulate insulate insulate, and make use of passive solar gain (south facing windows - triple glazed) the better a house is built, sealed and insulated the less it costs to heat.
 
Sorry to clairify on p.1 as may not have answered your question - no the heat pump works to a claimed temp of -20. But in colder conditions it does use an internal heating element as a backup. If the outdoor air unti is frosting it send out intermitten cycles of hot water to defrost the unit
 
Thats brilliant dj01 thanks,
we have budgeted every extra penny on insulation so agree with you there. gas not an option for us as we are not on the pipeline. am deciding between heat pump Vs condensing oil burner with stove boiler as back up. whichever system I choose I plan to get the HRV.
Im a bit surprised that you would not choose the heat pump again given that you are estimating an annual bill of 2000 euro for all your heat, hot water & electricity in a house of 2900 sq foot. I would have thought this was very very reasonable ?
Its hard to see how other systems would cost you any less (obviously there is the additional cost at the start).
 
Didn't say I wouldn't choose it again, but would explore all other options fully as you should do. You can get a gas storage tank so don't need to be on the mains supply line. In terms of cost comparing with oil is'nt a true comparison as with the heat pump you have contstant heat (we have had at least during winter), so on a like for like basis against oil it's alot cheaper. UFH works best where the floor is kept at a constant 'base' temp as it's a slow response system.

Best of luch whatever you decide.
 
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