Car air con

Jamie_Carter

gardner1 wrote: »

having air con on lowest setting will make little difference in fuel consumpsion

I'm no expert on air conditioning. But from what I have been told, it's the fact that the air conditioning is running that uses more fuel, and has nothing to do with the speed of the fan.

Weird_Nev

Jamie_Carter wrote: »

I'm no expert on air conditioning. But from what I have been told, it's the fact that the air conditioning is running that uses more fuel, and has nothing to do with the speed of the fan.

No, but the air compressor can exert variable drag on the engine depending on how hard it's working. If you ask a climate control system to cool the car to 15 deg on a 40 deg day, it will be working flat out and could be consuming something like 10 horse power. On a 21 deg day where you want the interior at 18 deg, it won't be working nearly as hard, and so it will use much less energy.

It's exactly the same principle as an alternator producing variable load on the engine depending on how much current is being drawn from it.