matching a compressor, condensor en evaporator capacities.
matching a compressor, condensor en evaporator capacities.
(OP)
what guide should be followed when selecting a certain compressor condensor unit for a certain evaporator?
suppliers gives a table with different evoparor temperaturs ( or suction temp on the compressor). How do you select the evaporator temperature?
what other aspects should be taken into acount when matching the compressor and evaporator?
where can I find guidelins in this regard?
suppliers gives a table with different evoparor temperaturs ( or suction temp on the compressor). How do you select the evaporator temperature?
what other aspects should be taken into acount when matching the compressor and evaporator?
where can I find guidelins in this regard?





RE: matching a compressor, condensor en evaporator capacities.
Consider the liquid refrigerant temperature entering the evaporator coil to be similar to an entering chilled water temperature. It doesn't need to be any colder than what's necessary to achieve the desired leaving air condition. In general, it is up to 5F less than a chilled water application - which explains why refigerant coils usually have several less rows than water-based counterparts. Higher entering refrigerant temperatures result in less energy consumption by the compressor and condenser fans. Select the evaporator coil with 10-15F superheat to avoid sending liquid back to the compressor.
The evaporator and compressor/condenser must be "matched" at your load condition. Manual selection is painful. Graph both evaporator capacity and compressor/condenser capacity versus a common temperature somewhere in the circuit - usually entering or leaving the evaporator. Operation will be at the intersection of this "X" - matched as they say. Of course this intersection must occur at the capacity you need.
Use a Colmac or Heatcraft coil selection program to try different evaporators and get a feel for the variables. Then, with results from the coil program plus allowances for other pressure/temperature changes in the system (read suggested manuals or equivalent), select a compressor/condensing unit and graph as suggested. Let a trusting vendor confirm your results.
Anyone with day-to-day experience, please feel free to elaborate. Years may pass between times I need to do this, and I always have to brush up, but all material is at work and I'm not.
RE: matching a compressor, condensor en evaporator capacities.
Evaporator Temperature Ranges
Application Approved Evaporator Temperatures
Air Conditioning +32ºF to +55ºF
Improved Performance Air Conditioning +32ºF to +57ºF
Heat Pump (Approved Models) -15ºF to +55º
High Evaporator Temperature +20ºF to +55ºF
Medium Evaporator Temperature -10ºF to +30ºF
Low Evaporator Temperature
(Normal Torque Motor) -30ºF to +10ºF
Low Evaporator Temperature
(High Torque Motor) -40ºF to +10ºF
Commercial Refrigeration 0ºF to +50ºF