ground vs air heat pumps

jdesbt

:cool:hi .., i am wonrdering if anyone can advise me on effeciencys on air to water vs ground to water heat pumps,, pros and cons of each..., i am considering both options for a new build near the coast in donegal and cant decide which one is best.,. does air to ground work in very low temps like this winter.,.

thanks for any help

heinbloed

Expect the worst from both, you might be surprised then how good they can be both. But expect what the salesman says on the door step and you'll be cursing.

See here:

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

Each photo in this report shows a typical sample of a bad installation. Ask your salesmen if they can point it out and come back and we discuss their incompetence ( or straight lies ! ).

Always ask for a guaranteed heating SYSTEM performance, get this signed and guaranteed.
Always ask on which basics they have used which calculation to determine if your installation is right or wasted money, as it says in the report above.

Demand an energy demand/coverage calculation according to EN standard and a cost calculation of the ENTIRE heating system incl. a full service contract. For lets say 10 years, guaranteed.... and you'll see them running.
Get everything signed and guaranteed by the manufacturer AND the installer.
Both can go bust, better have two signatures.

And contact a heating engineer to advise you independant.


You can check this independant field research page as well:

http://www.waermepumpen-verbrauchsdatenbank.de/index.php?lang=de


I scratch my head and wonder why there is hardly any come-back from the UK and Ireland. Well, I'm not wondering actually (smiley)....

refco

hard to say which is best but what i would say is be careful get them sized by as many different companies as possible anyone undersizing or claiming that there unit has a cop of more than four get rid of them
Ask what level of insulation on the house is expected
what cop has the unit
run time from 10 degrees to 70 degrees
are they basing heating on rads/low temp rads/under floor
how low ambient before effiency is effected
defrost type
how much do electric elements get used and what kw are the elements
is this system suitable as a stand alone
are you using a well known brand ie if you where investing money in a car would you buy one you never heard of
and how acessable are parts for their system
Finally could you meet with a coustomer with this brand of unit in there own house of a similar size to yours and make sure you talk to them without interferance from salesman so you can get honest feed back and could you see an esb bill for last four or six months

by the way i have installed a lot of them for a company who now no longer exist but there main downfall was under sizing and the lies they told trying to make the sale
Never believe the line a payback within five or seven years

jdesbt

thanks for advise, is the air pump noisey and does any one know if they work efectifely at temps down to -12 or so

jdesbt

one more dumb question(2) but what does cop mean and what do you mean by run time 10 to 70