Air conditioning

[cito quod fortis]

Hi. I’ve just got round to putting my air con system back together (in time for winter!) and have a couple of issues I need to sort. I don’t think it ever worked all that well in the past, the compressor died just over a year ago and I’ve been doing without it until now.

Now all is put together with a new compressor, charged and balanced, it works great when the car is stationery, but when I drive it, as soon as I get over about 2000 revs, it’s no longer icy cold and by about 3000 revs, it’s blowing a little bit warm.

I can’t increase the pressure in the system as the compressor is pretty close to its limit and I can’t change the compressor as I can’t get another one to fit in the space.

One of the problems seems to be the heat in the engine bay. With the condenser being by the drivers side vent, not all that much air comes in when moving and the engine heat keeps the area warm. Maybe the condenser isn’t man enough for the job, but there’s no space for a bigger one. I could try to find space for an additional one, possibly in front of the radiator at the front, although I’d be a bit worried about restricting the cooling to the radiator if I did this.

On the positive side, my engine temperatures are running about 2 degrees lower when I have the air con running and at least I keep cool when in traffic jams.

Is this a fairly normal problem with the air con? Any help or suggestions would be welcome.

Cheers. Andy

[Zoobeef]

many many cars run the ac rad infront of the engine radiator so i cant see it being a problem

[Storer]

Are you sure that the heater is fully isolated, as there is no way running the aircon will lower the car's temperature. If anything it would be more likely to raise it.

Check the temp of your heater pipes in the cabin.

Paul

[F.C.]

Your heater valve is almost certainly by-passing hot water and as the aircon/heater system doesn't consist of a mixing box the aircon shares the same airpath as the heater matrix and so is fighting to cool hot air.

I fitted a secondary valve to completely isolate the heater matrix to give the air conditioning a chance.
Works a treat!