Just exactly how does my A/C work?

Air conditioning is really not a very complicated process.  

Simply put, your A/C removes heat and moisture from the air inside the house.  It does so using a fairly complex system of copper tubes fans, valves, wiring, and other things that all play an intricate role in conditioning the indoor air.

1. The outdoor compressor and indoor condenser (in most cases) are two different yet linked components. The outside compressor is a small tank that sits inside that large metal box.  There is a motor with a fan attached just under the top of the compressor and some electrical and copper pipes that run into the house called the line set.
2. At the outside unit, the compressor physically compresses cool refrigerant gas under high pressure to form a hot vapor.
3. This liquid hot vapor is pushed through the smaller "liquid line" to the condenser coils inside the house.
4. The hot refrigerant liquid runs through an expansion valve inside the coil, causing it to evaporate and become cold gas again.
5. The cold freon gas flows through set of small tubes or the evaporator coil located just above (horizontal system) or just down stream from (vertical system) the furnace.
6. The fan at the air handler (bottom part of the furnace) then turns on and blows air across the evaporator coil.  The home's air becomes cold and travels through a the supply pleunum, supply ducts and finally into the rooms through the supply registers.  
7. The air is then sucked back or returned to the return air plenum located near the thermostat.  The air is filtered here before the warm ambient air is recirculated back toward the coil to start air circulation process all over.
8. The freon gas that has passed through the evaporator coil and picked up the heat and moisture from the air is then returned back to the compressor outside through a larger pipe called the "suction line", where the heat is removed from the refrigerant.  Then, refrigerant cycle starts all over again.  
9. The moisture removed from the air at the coil drips off the coil into a pan and drain out to a primary drain line.  This drain line runs water whenever the A/C is operating.  If the primary drain line clogs up with mold, the system should overflow into a secondary drain system (how to keep the primary drain line from clogging).
   

Never operate your compressor when the outside temperature is less than 60 degrees.  Because the system relies on outside temperatures of 70 degrees or better, there is a risk of damage to the compressor.  You always want to have your HVAC system serviced in the late spring to make sure everything is working for the coming summer.  Thinking your system cooled last year does not mean that everything is fine.  A system might feel cool but may not operating efficiently.  It may also be running out of refrigerant through a small leak that will crash your system in August.  


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