Cooling
Testing A/C System and Heat Pump - The circuit breakers to A/C should be on for a minimum of 24 hours and
the outside temperature at least 60 degrees for the past 24 hours or an A/C system cannot be operated without possible damage to the compressor. Check the instructions in your A/C manual or on the outside compressor before starting up in the summer. Heat pump can only be tested in the mode it’s running in. Outside temperature should be at least 65° for the past 24 hours to run in cooling mode.
Temperature differential, between 14°-22°, is usually acceptable. If out of this range, have an HVAC contractor examine it. It is not always feasible to do a differential test due to high humidity, low outside temperature, etc.
A/C systems should be serviced by a professional each year. Most experts agree you will pay for the service cost
in electricity saved by having the system cleaned & tuned for efficiency yearly.

A/C Compressors
They should not become overgrown with foliage. Clearance requirements vary, but 2’ on all sides should be considered minimal with up to 6’ of air discharge desirable. If a clothes dryer vent is within five to ten feet, either relocate the vent or do not run when the A/C is running. The lint will quickly reduce the efficiency of the A/C unit.