Air con queery.

[impvan]

Originally Posted by Brunty

How much engine power is lost to use of aircon?

A couple of horsepower or so.


The inside volume of the car is comparable to a small walk-in fridge. Such a fridge can be easily cooled to just 2'C with a 2hp compressor.
Allow for the lack of insulation compared to a fridge, air replacement, and set against a target temp of, say, 16'C - and you can see that the air con doesn't need much.


However, the effect of the 2hp depends on what the car is doing at the time...


At 70+ on the motorway, the aircon demand is negligible compared to the ~40hp being used.
At snail's pace in city traffic, the aircon demand is a big part of the ~5hp being used.