Please answer a question about Volvo AC

[ffhdriver]

A few years ago I owned 1987 and 1990 Volvo 760 models. On both these cars, when using the AC, the outside of the plastic under dash AC housing was covered with condensate which dripped on the carpet or passenger's feet. AFAIR the condensate hose was not plugged. I put up with it and never had the dealer check it. This happen both when the air mode was fresh or recirculate. Just wondering, after all these years, what caused that? High level of condensate in housing?? TIA

 

[mechtech2]

If that area was cold enough, water could condense on it [outside].
This is not usual. It would have to be pretty cold.

There is a possibility that some condensation/liquid that should be draining out the bottom may be leaking to that area.

 

[robshelton]

IMHO there is enough humidity in lower Alabama for condensation to form on the outside of the evaporator case and AC ducts like a glass of cold water/tea/soda/pop/beer. I think I rode in an S 40 that did the same thing a while back.

 

[Craig in Canada]

Yes, but after the system ran for just a couple of minutes the air inside the vehicle should not have had enough humidity left in it to do this, unless you drive around with all the windows down and the AC on (I presume not).

Particularly in recirc mode, it will only remove the humidity load from the cabin air once and thereafter it only has to dehumidify whatever the occupants are giving off in breath or sweat.

I`ve had pretty cold AC, and have had condensation form on the outside of the glass when I wanted, but I`ve never had a `sweaty glass` condensation problem inside the vehicle.

I wonder if there was a partial blockage of the evaporator drainage system (not the tube, but a solid object in the path of flow) or if the casing was not assembled properly after some kind of nearby repair.

 

[robshelton]

I'm thinking the ducting is too small for the vehicle's interior size, i.e. the system doesn't have a high volume (CFM) and is the owner keeps the AC on a high setting to keep the cool air blowing.

I don't know if you have been down near the Gulf of Mexico, but sometimes the heat and humidity is amazing. Many call it oppressive but it's almost paralyzing for me! It's not as bad here, but I've had condensation on the inside of the glass a couple of times when I was down by the coast.

I do agree with you in that there seems to be more here than we can know and there was probably an issue with the AC somewhere.

 

[CBR.worm]

I am down in Florida, most of my cars have dripped water on my feet from condensation on the outside of the plastic ducts at times.

Get moisture around the vent outlets as well.

The worst was a '91 ford escort GT. Great AC, actually a good little car all around. 196k on the OE clutch. No real issues other than the AC clutch eventually wore out right before I sold it.

 

[mechtech2]

Actually, in recirculating mode, moisture is NOT removed like normal. Colder, but definitely wetter.
This can also be a contributing cause.

 

[ffhdriver]

Thanks for all the replies. As Craig in Canada says I've thought that something kept an abnormal high level of condensate in the housing. I've never had another car do this.

 

[mechtech2]

At least you can be happy it is working cold enough to do this!