Air Source Heat Pumps & SPFs

BarneyMc

I'm looking at quotes for 2 air to water heat pumps (both prices include the hot water tank):

Heat Pump A
SPF: 413
Price: €12,350

Heat Pump B
SPF: 363
Price: €9,000

Is heat pump A worth the extra money if my estimated heating bill, using pump B is €880?

Condenser

BarneyMc wrote: »

I'm looking at quotes for 2 air to water heat pumps (both prices include the hot water tank):

Heat Pump A
SPF: 413
Price: €12,350

Heat Pump B
SPF: 363
Price: €9,000

Is heat pump A worth the extra money if my estimated heating bill, using pump B is €880?

You cannot determine the SPF until the system is up and running. The SPF is the actual COP over a given time.

If you're being quoted COP then what are the figures its being quoted at A7/W35 or A2/W35. The later is the european standard and as such is the figure that should be quoted. Anyone using A7/W35 is just massaging the figures to make them look vaguely comparable to ground source units.

BarneyMc

I was using this site to compare SPFs which I thought would be a good benchmark.

I'll see if I can get the A2/W35 COP then. Is there a central site for these HP COPs or is it just a matter of contacting the supplier?

BarneyMc

OK, just looked up the Heat Pump B details and the COP is 4.3 at A7/W35!

Interesting, I'll ask the supplier what the 'real' (European) COP is.

Condenser

BarneyMc wrote: »

OK, just looked up the Heat Pump B details and the COP is 4.3 at A7/W35!

Interesting, I'll ask the supplier what the 'real' (European) COP is.

if you can't find it on the irish or english brochures google their german sites, they'll nearly certainly have it on there.
Bare in mind that figure ignores defrosts, hot water production and any use of the immersion. It is also installation dependent so can varying on the competence of the installer

BarneyMc

Got the info about COP values so the full picture is (prices include hot water tanks):

Heat Pump A
COP: 4.3
SPF: 413
Price: €12,350

Heat Pump B
COP: 3.5
SPF: 363
Price: €9,000

Does this make it any easier to pick a winner?

Condenser

No because they're talking crap. No one can give you an spf until the system has been running in your house for one season at least. Your installation will determine your spf not some rubbish written on a brochure.

COP, s will tell you so much but its how you distribute the heat, at what temp and how its controlled will determine the outcome and spf on an a2w system.

Therefore if the cheaper unit with the lesser cop were installed better it would give you a better end result than the more expensive unit installed badly.

BarneyMc

Condenser wrote: »

No because they're talking crap. No one can give you an spf until the system has been running in your house for one season at least. Your installation will determine your spf not some rubbish written on a brochure.

COP, s will tell you so much but its how you distribute the heat, at what temp and how its controlled will determine the outcome and spf on an a2w system.

Therefore if the cheaper unit with the lesser cop were installed better it would give you a better end result than the more expensive unit installed badly.

So basically what you're saying is try and get an installer with a proven record rather then comparing HP brochure claims?

Condenser

BarneyMc wrote: »

So basically what you're saying is try and get an installer with a proven record rather then comparing HP brochure claims?

Exactly. COP's only indicate how efficient a unit is at a certain energy extraction and energy delivery temp. Whether your system works above or below those temps depends on your installer.

fclauson

http://www.danfoss.com/NR/rdonlyres/90B037DC-428F-4852-BAD9-E701D34519A0/0/DHPAQ_TEST_RESULTS_SE.pdf

This is only posted as it shows a number of heat pumps compared

also see
http://www.energimyndigheten.se/Hushall/Testerresultat/Testresultat/ and look at "air heat pump"

My chrome browser will automatically translate these pages

Tommyboy08

fclauson wrote: »

http://www.danfoss.com/NR/rdonlyres/90B037DC-428F-4852-BAD9-E701D34519A0/0/DHPAQ_TEST_RESULTS_SE.pdf

This is only posted as it shows a number of heat pumps compared

also see
http://www.energimyndigheten.se/Hushall/Testerresultat/Testresultat/ and look at "air heat pump"

My chrome browser will automatically translate these pages

I think its great that companies can put out brochures claiming to be the best and most efficient but on that test there where was oschner, heliotherm, Alphainnotec, idm? I know that at least three of these have higher cops than the Danfoss,
The results were not spectacular, there was very little between units, I would like to see the tests carried out with the German and Austrian units involved,

Also I would like to see other manufacturers show their test results from the sepimo project

wilmul80

Hi all I'm new to boards so forgive any mistakes.
I'm building a house at the moment and leaning towards air to water heating as house is 3400sq ft and I feel oil will rob us . It is well insulated and I'm aiming for airtightness. Has anyone had this system fitted recently . Any feedback is greatly appreciated .

Curious Geroge

wilmul80 wrote: »

Hi all I'm new to boards so forgive any mistakes.
I'm building a house at the moment and leaning towards air to water heating as house is 3400sq ft and I feel oil will rob us . It is well insulated and I'm aiming for airtightness. Has anyone had this system fitted recently . Any feedback is greatly appreciated .

Did you go with an air to water system in the end ?