designing a heatpump

[ianandkitty]

Hi
Can anyone help me im making a ground source heat pump to do heating only in my home.
i need cond temps of 40-75 oC for heating and hot water
I have been looking at copeland scroll compressors
Looking around most heatpumps seem to run on r410a
but i dont think this can get the tempratures im looking for.
http://www.ecopeland.com/prodcat.cfm...ref=7&prod=528

but would i be better using r134a as i think this will reach the desired temp http://www.ecopeland.com/prodcat.cfm...f=8&prod=30692

But i must have a good c.o.p. r410a heatpumps seem to have a cop of around 3-5 but i cant find any heatpumps using r134a

i know that my ground loop water through my evap will be at a constant 4-8 oC

so would that suggest that 410a is a lot more efficient than 134a??
any help please before i buy an expensive compressor thats no good...

[Lc_shi]

I think you can use normal condenser for heating and desuperheating for hot water. R134a's cop is a little higher than r410a ,but with lower discharge temp. r410a's compressor and piping system should be more expensive. Detail compare the cost before you decide to use r410a or r134a. there's lot things to consider. If you need help,let me know your requirement and i'll make calculation for you:)

regards
LC

[NoNickName]

I would suggest to use ZH series from Copeland and R407c. ZH are available with vapor injection and show a very good behaviour at high condensing pressures.
I'm designing a heater with 63°C condensing temperature for deliverying warm water at 60°C. Heating capacity 60kW, power absorbed 18kW.

[Andy]

I would suggest to use ZH series from Copeland and R407c. ZH are available with vapor injection and show a very good behaviour at high condensing pressures.
I'm designing a heater with 63°C condensing temperature for deliverying warm water at 60°C. Heating capacity 60kW, power absorbed 18kW.
What about a Bitzer Octagon on propane:)

More effecient compressor and a substainable refrigerant.

R134a, not a high enough effeciency:(

R410a better effeciency, but high pressures in a heat pump that will be condensing at 55 deg c:eek:

R407c just don't like it, very suspect performance, tendancy to fractionate, and only used until something better comes along, also quite a glide, not what I would be using on a water based system.

Kind Regards. Andy.

[NoNickName]

Bitzer octagon on propane is fine, as long as the unit is designed properly under the requirement of PED group 1 refrigerants.