Location of condensing units

[lodiroon]

What effect on the system does the location of the condensing unit have, i.e. 2-5 floors above the evaporator, or approximately 40 to 60 feet?

[ar]

The liquid line pressure will increase at the evaporator approx. 5 psig for every 10' condenser elevation above it. Oil return to compressor must be considered, oil trap in suction line at evap. and every 20' up from there. Consider liquid line solenoid for pump down cycle to prevent liquid floodback at start up due to evap. possibly being full of liquid refrigerant.

[seaboard]

Go to Trane or Carrier and get a piping design manual. They are great to have and the good thing about the "laws" of piping are that they are the same today that they were 30 years ago. The piping book I use was printed in the 60's. With the condensers above the evaporators, piping to allow for oil return will be your primary concern.