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MikeHolm
29-12-2010, 04:41 PM
Here is the situation: I want to put the Evap coil of the HP on an outside wall, high up and the compressor is in the basement. The height difference is 9-10m. Is it possible to do this with a standard 410 copeland scroll? What are the general (if possible) rules of thumb for coil placement?

NoNickName
29-12-2010, 06:45 PM
Higher refrigerant charge and higher oil charge. Oil traps along the rise, at least every three meters. Inverters are not recommended here, unless double risers are used.

MikeHolm
30-12-2010, 01:27 AM
Thanks for the answer. I know how to do pump sizing for hydronic systems but I do want to find out how to determine the piping limitations (head and flow) for compressors as it is definitely different than straight liquid flow.:) forgive me if it is a complicated question.

NoNickName
30-12-2010, 11:01 AM
There is a dedicated chapter in ASHRAE refrigeration manual. Few well spent dollars.

Kalmar
31-12-2010, 04:38 PM
Here is the situation: I want to put the Evap coil of the HP on an outside wall, high up and the compressor is in the basement. The height difference is 9-10m. Is it possible to do this with a standard 410 copeland scroll? What are the general (if possible) rules of thumb for coil placement?


There will be no issues about oil return (downflow in suction line, isn't it?). Critical point is evaporator (design), placing of EXV and superheat sensing bulbe or sensor (on EEV), venturi, etc. Especially, if system is reversible.
Horizontal coils (with vertical air-flow) are better than vertical coils. Unspoiled air flow through evaporator is of umost importance (no obstacles, no recirculation...)

MikeHolm
03-01-2011, 12:59 AM
The purpose of the placement of the evap coil high up on the wall is to create a "trombe" wall cavity using a solarwall (black perf aluminum or galv steel) to pre heat the coil from waste heat given off the the brick wall and from the sunshine. All in the name of improved COP in colder temps. Evap design will be to maximize the stack effect, minimize the fan power for airflow vertically through the slab coil.