That's a great explanation, Larry. Let me add one practical thought for someone who is going to install a unit for the first time, or replace an existing unit. From the point of view of airflow paths, there are two different designs. Either one will work, but you have to know which one you have.
1. In some units, ambient air (meaning outdoor air) enters the unit from the side, passes over the radiator for the compressor where it picks up its heat load, and is exhausted out the back of the unit. Meanwhile, indoor air enters the unit from an area of the front, passes over radiator for the evaporator where it is cooled, and is expelled back into the room through a different area of the front.
2. Outdoor air enters the unit from a part of the rear face, passes over the radiator for the compressor where it picks up its heat load, and is expelled back outdoors through a different area of the rear face. Meanwhile, indoor air enters the unit from the sides, passes over the radiator for the evaporator where it is cooled, and is expelled back into the room through the front.
You can tell which one you have by simply setting it on a table, starting it up, and passing a strip of paper or Kleenex around the unit to see where air enters and where it leaves. Either way works, but you have to know which one you have in order to setup the baffles (shrouds) that keep the air streams separate.
Bill
|