A/C Compressor Turning On and Off
Senior Member
Joined: Jun 2005
Posts: 672
Likes: 0
From: Allentown PA, - Phila, PA
A/C is just a heat engine in reverse...
Instead of getting work, in the form of Horsepower, out of the motor while heat is generated, an A/C system uses a compressor to remove the heat from the air, by doing the work to compress the gas... Look at any physics book...
Some systems cycle on and off, some do not... the pressure from the "hot" side increases cause of the hot air the refreigerant is absorbing inside of the evaporator... The cooler refrigerant absorbs the heat from the car, and while doing so, it gains enough energy to evaporate into a gas...
Once this hot, pressurized gas has absorbed enough heat from the cabin, it travels down the condenser (radiator looking thing) and while traveling down, the heat transfers to the outside air, and the gas condenses back into a liquid, hence the name condenser...
If the pressure becomes too high on the "hot" side, the compressor will shut off... Once the pressure is relieved, from the gas condensing back into a liquid, the compressor turns back on, starting the cycle over again...
If I'm not mistaken, most cars have a cycle type A/C system...
Mainly because of the use of "corporate" A/C compressors in many different vehicles... usually they are oversized for the system in which they are used...
Instead of getting work, in the form of Horsepower, out of the motor while heat is generated, an A/C system uses a compressor to remove the heat from the air, by doing the work to compress the gas... Look at any physics book...
Some systems cycle on and off, some do not... the pressure from the "hot" side increases cause of the hot air the refreigerant is absorbing inside of the evaporator... The cooler refrigerant absorbs the heat from the car, and while doing so, it gains enough energy to evaporate into a gas...
Once this hot, pressurized gas has absorbed enough heat from the cabin, it travels down the condenser (radiator looking thing) and while traveling down, the heat transfers to the outside air, and the gas condenses back into a liquid, hence the name condenser...
If the pressure becomes too high on the "hot" side, the compressor will shut off... Once the pressure is relieved, from the gas condensing back into a liquid, the compressor turns back on, starting the cycle over again...
If I'm not mistaken, most cars have a cycle type A/C system...
Mainly because of the use of "corporate" A/C compressors in many different vehicles... usually they are oversized for the system in which they are used...
