When describing air conditioning/cooling equipment, inspectors often discuss the high side and low side of the system. The high and low sides of a cooling system refer to system pressure, not to physical location. High-side components include the condenser coil, condenser fan and compressor. Low-side components are the evaporator coil and metering device.
Compressor: The compressor is the most expensive and functionally important part of a complete refrigeration system. Its purpose is to circulate refrigerant through the system. The compressor motor requires 208 Volts AC to 230 Volts AC or 220 Volt AC to 240 Volt AC. The inspector will operate the system and check for proper cooling. Inspecting for any defects and improper installation will be reported and recommendations made.

Evaporator Coil: The evaporator coil is also known as an indoor coil and is constructed similarly to the condenser coil. The function of the evaporator is to absorb heat from the air before the air travels to the conditioned space. This is accomplished by running refrigerant, which has a lower temperature than the air blown over the evaporator coil, through the tubing. During an inspection, if the outside temperature is too cold (as in the fall and winter seasons), the air conditioning system can not be checked. The inspector will make recommendations and advise obtaining current homeowner representation of operation of units.