ASHP and GSHP are, to a layman like me, basically the same technology with just the source of the heat being different. Is that a reasonable view? If it is, then one key factor affecting the COP is the temperature of the heat source. In real winter the ground is warmer than the air, so I would expect a GSHP to be more efficient, but there are times in the spring and autumn when you want heat and the air is warmer than the ground. At those times I would expect an ASHP to be more efficient. Is there something wrong with that theory? We have a GSHP and I have been wondering whether it would be worth supplementing it with an ASHP to take advantage of the warmer air temperatures in spring and autumn.
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What you must remember is how long is it over 12 dec ? A few hours a day. The rest it will drop back to below ground temps. Thus your ASHP would be good for the hours of 12.00-13.00 for 30 or so days a year hardly a great investment..
The data from the Finnish installation linked to earlier suggests this would not be a wise investment because the COP is never very impressive. I just don't understand why
When I posted that data it kinda took the wind out of his sales. He has been suggesting Sanyo UK can (and will) provide their own counter data. Sadly it's been 2 months of inaction which is worrying as the Finnish data is doing Sanyo ASHP's no good at all.If I was Sanyo I would have sent a team of engineers to investigate why the results were so poor to try to stem this PR disaster .Llet's see what happens...
Not really, i sent your link to 2 people that have a big interest in how these products work in comparrison to other brand ASHP specifically CO2 against HFC.
I haven't received any links?
However there is a big debate on how efficient CO2 actually is. In the refrigeration industry it's being seen as less efficient than HFC's. However I have had long discussions with a UK GSHP manufacturer who has suggested R410a is a poor HP refrigerant . Sadly the Japanese have been forced down this route by the politics of refrigerants so CO2 was seen as a 'friendly' alternative.
Unfortunately Ive not had time to chase or in all honesty the interest to chase,primarily because the data as real time as it is is installed in a climate that isn't even on comparison to ours nor is the product the newer Eco set.
I believe it was the last generation CO2 system. Performance increases in small %. To write off the old kit is a fudge and you know it.
Should the data have been form a site in london,the midlands etc then id certainly be pushing to know whats wrong,the fact that the unit is still above 1.5 seems to indicate that its far better than LPG,oil etc. the fact that the low outside temps dont affect the unit i would like to see the data for a comparable HFC unit in the same location.
You stated this:
the Sanyo unit will produce useable heat through out its working range all the way down ast-26 to a cop above 2 at those low temperatures,
It has been shown by that data that it hasn't got anywhere near -26 yet has failed to average anywhere near 2 !
In the mean time weve installed a sanyo eco and a altherma in identical new builds,both have heat meters and loggers attatched which we will use the results from to see how viable both products are against each other.
My argument isn't between Sanyo and Daikin. I rate all Japanese as of a similar quality. My argument is they are all pretty poor and are oversold to customers who end up paying through the nose for either higher running costs than promised or repairs which will stun domestic customers in 5 years time when Fridgie tells them it's 2k to change the compressor.
i'll ask the question again,but im in no rush to chase answers on old technology installed on foreign soil.
I'll tell you what I'll ask Sanyo and get back here.
Old technology ?? I thought CO2 was NEW technology!
Foreign soil or not the system isn't up to much and a Sanyo CO2 system averaging 1.5 COP is a poor investment in anyone's book..
