Car Air Conditioning: Energy Usage & Benefits

In summary, the conversation discusses the energy usage of running a car's air conditioner continuously versus turning it on and off intermittently while keeping the fan and vents running. It is noted that running the AC continuously uses more energy due to the compressor being belt-driven and causing drag on the engine. However, it is also mentioned that car air conditioners are not capable of varying their capacity, so running it intermittently may be more efficient in the long run. The set points selected by the car's manufacturer may also affect efficiency. It is also mentioned that leaving the vent open while cycling the AC can be counterproductive and that it is more efficient to use the recirculation vent setting. The conversation also touches on the use of thermostats in cars
  • #36
Ranger Mike said:
not true
you have to run the A/C once a month , every month to keep the seals " lubed up "
,,,,90 percent of A/C problems are leaks in the system...
so hit the A/C button once a month for a few minutes to prevent big $$$$ costs
I've never heard that and it doesn't make any sense to me (I'll check my manual though), but in any case, Danger was apparently running it all the time.
 
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  • #37
redargon said:
I've heard this too, but i always forget to turn it on in winter 'cos it's so freaking cold outside. The best way is to use it to demist the inside of the windscreen.
If you turn the AC on, but turn the thermostat all the way up, it will run the compressor and then reheat the air with engine heat. It is actually a good way to warm up a car on a cold day.
 
  • #38
AC has three basic assemblies..compressor, condenser and evaporator.
the compressor is a belt driven " pump" with Electro magnetic clutch assembly..it also has numerous " rubber" O-ring seals...you have many "' rubber " ( ok.. synthetic material now a days) seals...these need to be lubricated to prevent drying out and leaking...the same scenario as storing an automobile over the winter...the biggest problem in storage besides cylinder surface rust is seals drying up...axle seals, transmission drive shaft seals, crankshaft oil seals, master cylinder seals. wheel brake cylinder seals and clutch master cylinder seals is so equipped..and the air conditioner seals...
you got to keep um lubed. Refrigerant like R12 has mineral oil in it and the new EPA crap R134A has PAG oil. both of these oils are to lube the seals and the compressor vanes...
this is why you should run the A/C for 10 minutes EVERY MONTH to keep the seals from hardening..thus leaking..the most common A/C prob is low refrigerant...savvy?
 
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  • #39
I understand the explanation and it seems like it should make sense, I've just never heard it before and don't see why it would be true that the seals would dry out or cylinders would rust.

It just sounds to me like the Seinfeld episode where Jerry has George "exercising the gaskets" on his toilet.
 
  • #40
Good One...That is why you all are so lucky to have a guy like me posting on occasion...

Reminds me of that guy named Chris...who ran into a lot of people saying they understood his explanation but never heard it before and didn't see why it would be true. All he got was a city named after him in Ohio.
 
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