Basics of mechanical cooling systems for multifamily property owners. A thread

There are 3 components to every air conditioning system. The compressor, the condenser and the evaporator.

The Compressor takes refrigerant in a gaseous state and compresses it. The heated gas leaves the compressor and heads toward the condenser.

There are several types of compressors, however most residential systems will have scroll compressors.

The Condenser receives hot gaseous refrigerant from the compressor and cools it into a liquid state. Note, there are three types of condensers, air-cooled, water cooled and evaporative. Most residential systems are air-cooled.

The evaporator receives low temp, low pressure liquid refrigerant from the condenser, restricts its flow via an expansion valve and changes the phase of refrgnt from liquid to gas as refrigerant boils while absorbing heat. This delicate balance becomes the cause of most issues

A note on phase change. The system converts from refrigerant from liquid to gas and back again, why? Converting phase takes large amount of energy. Heating 1 pound of water 1 degree is 1 BTU. Taking 1 pound of water from 212F water to steam? That takes 970 BTU!

Later this week I’ll cover different types of multifamily systems, systems design and maintenance/trouble shooting.

Happy to answer any questions. I will update the thread as appropriate. There’s a lot that goes into these systems and knowing where to start and how much detail is appropriate is tricky. What do you want to know?