I am looking at replacing a 30 year old furnace with a heat pump on southern vancouver island. I am wondering if a desuperheater would work with an air source hp that would be heating 98% of the time that its on. As we get nice ocean breezes in summer, we would use less than 10 hrs/year.
I don't know much about the actual setup of a desuperheater but it seems the best way is to use as a preheater for the regular hw tank. My neighbour is replacing his hot water tank with gas and I may be able to use his old electric for the desuperheater. Has anyone seen any good sites that give a good run down of what the desuperheater looks like and how it gets installed. Since it isn't main stream up here, I'd really like to have a better idea about how they are installed properly. What sort of compatibilty issues would there be in signalling etc. with the hp thermostat?
Might try Climate master or Water Furnace branded Ground source sites, I dont have the link but I will look for it. May just try a search.
Proud supporter of Springfield Millers and Oregon Ducks.
To my knowledge a desuperheater is used to bring refrigerant temperature down to saturartion temperature of the prevailing conditions and then on thru the condensation process.
I have concerns that mis-applied this device could cause you problems on liquid subcooling.
It is possible to cool liquid refrigerant too much which result in equip malfunction.
I would certainly have concerns if it was not designed into the system from the manfactuerer.
I have seen R502 systems in supermarkets run the compressor
discharge into a nearby water tank for potable hot water usage but careful consideration taken in sizing ect to ensure the R502 system worked well in unison with the water tank.
[Edited by curry on 10-25-2005 at 11:10 AM]
Reading my post, I could have been more clear. We might cool the house for a total of 10 hours a year and our heating season might be 7 months of the year with short dips below freezing.
So if I understand your reply, during the heating season feeding the refrigerant through another coil in a water tank after going through the ahu coil might cool the refigerant too much. What happens if the refrigerant is too cold?
What about redirecting warm refigerant to a water tank with some kind of valve once the space heating requirements have been met? Is this done?
I can easily see how a desuperheater would work well in the cooling season by taking the waste heat out of the refrigerant but I can't find any details to tell me if they work at all during heating season when there is no "waste" heat?
A desuperheater is connected to th ehot gas discharge of the compressor, so it would be before the ahu.
Many have an operating limit, to prevent from cooling the gas below 120°.
beenthere is right, the superheat is what you use to heat your space, if you are going to steal it before it has an opportunity to heat the house then all you end up with is a high end waterheater. They already make HP water heaters.