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Old 05-03-2017, 07:51 AM   #28
Tcoat
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Drives: 2020 Hakone
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Quote:
Originally Posted by PandaSPUR View Post
Yep, theres the problem. Compressor runs off the engine and relies on airflow created by movement of your car. No movement = no airflow = hotter compressor = less cooling inside.
Doesn't really matter how hot the compressor runs. That isn't where the cooling happens.
Heat is removed at the condenser which is downstream of the compressor. Hum is correct in saying the fan removes the heat at that point. You are also correct though since a moving car sheds heat better than a stationary one. The more efficiently heat is removed from the condenser the more efficient the system works. As mentioned the engine bay is packed pretty solid so our AC isn't the most efficient out there.

Quote:
Originally Posted by Ultramaroon View Post
It's just how it performs. Your and strat's experience matches mine. In heavy traffic my temperature control is a choice between recirc or fresh. :|

It does great once I get moving. The compressor doesn't really keep up with the evaporator below 2K RPM
Yep. This is where the compressor comes in. At low RPMs it just isn't moving enough gas to the condenser too turn it to liquid. Not enough liquid at the condenser means not enough is turning back to gas at the evaporator to remove the heat from the passenger compartment. Poor cooling at idle is not unusual for small displacement engines since a larger compressor that would move more gas would rob too much power. Combine this with the hot engine bay and you have an AC system that is happiest when moving with higher RPMs.

Now what is "cold" is subjective to individuals so when one guys says his is freezing and another says his is still warm it could very likely be exactly the same temperature in the car.
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