Trying to solve the frustrating A/C condensation problem

Those of us who live in humid places have to deal with the annoying problem of the evaporator box getting condensation on it, which then drips onto the floorboard. With warmer temps on the way, I'd like to figure out ways to solve this problem since it doesn't look like Toyota is going to solve it for us.

I'm wondering if wrapping the evaporator box in some kind of insulation would prevent condensation from forming on it. Then again, I don't want the insulation itself to get cool and have condensation form in it and then get mildew in it.

And yes, I know that if I keep the air on recirculate then the AC will, in theory, dry the air out inside the cab and I shouldn't have this problem. However, in places like where I live (Houston) that are really humid in the summer, even keeping the air on recirculate doesn't prevent this.

Anyway, has anyone out there found a DIY solution for this?

 

I live in SE Georgia, where it's not uncommon to have 100% humidity. I don't get water dripping on my floorboards at all. I do run the remote start every morning to clear out the extra humidity before heading to work, but that's it. So far, have had no mold or mildew issues, including smells.

 

Insulation cant grow mold. Mold can only grow on organic material, think paper etc, not fiberglass.

 

You may have another problem. Because we have as much humidity as you, and it's not an issue here in Florida.

Typically I've seen this when a vehicle already had moisture inside from something else, like a leak. Running the AC gets the now 'wet air' in the cab moving, and it condenses on the cold surface of the case. Like when you've had a warm-ish humid spell and had the windows open in the house, and a big cold snap hits, making the insides of your windows 'sweat'.

I'd be examining the truck for moisture sources. A clogged AC drain line and the problematic 3rd brake light would be starting points.

 

Florida here as well and haven't had an issue at all with humidity. I could see it happening if you are running on fresh air all the time because you are constantly bringing in humid air, but once you run on recirculate and don't have the windows open or frequent door openings, it shouldn't be a problem. Like Bill said, check your drain and you may want to check your evaporator to make sure it doesn't have mold build up. Also check your cabin filter.

 

Agreed that OP has another issue. You shouldn't be getting condensation inside the vehicle from the AC running. We also regularly see high humidity here in Michigan thanks to the Great Lakes. This has never once been an issue for me.

I have gotten the moldy smell from the vents, but that usually only occurs after not using the AC for a while and starting it up again. It goes away with regular use.

 

This is weird. I've done all of the things everyone is suggesting, multiple times, yet I continue to have water dripping on the passenger floorboard while running the AC, even on recirculate. I never get leaks in the cab after a hard rain, so it's not a leak. I've cleared out the drain line (and I get plenty of water coming out of the drain line while running the AC).

Here's a photo I took last summer when I was trying to trace the source of the dripping. You can see water along the left edge of the vent, and just to the left of the edge. It's not coming out of the vent but from something above it. What's up there?

 

Your drain tube is probably clogged

 

I've cleaned it out many times and have never seen anything come out of it, plus when I'm running the AC, I get plenty of water dripping out of it.

 

Water dripping into the cab is not normal, I have never experienced this in either of my 3rd gen Tacomas. Why is Toyota not willing to cover your issue under warranty?

 

I've had the dealership investigate it and was told that it was "functioning as normal." There are some other threads here of other people experiencing the same thing. They've cleared out drain lines, verified no water leaks, changed cabin air filters, run the AC on recirculate, and yet are still getting condensation inside of the cab that drips onto the floor. They have also taken theirs to the dealership and have been told the same thing.

 

Exactly. OP, you do know how air conditioners work in a vehicle right?
Here's a quote:
"The air-conditioning system in a car works by manipulating refrigerant between a liquid and a gaseous state. As the refrigerant changes states, it absorbs heat and humidity from the vehicle and allows the system to give off cool, dry air."
Note that part on the heat and humidity...

In addition, one part of the 2nd Rule of Thermodynamics states:
"In physics, the second law of thermodynamics says that heat flows naturally from an object at a higher temperature to an object at a lower temperature, and heat doesn't flow in the opposite direction of its own accord."

What I basically am saying is... You got a problem and your AC is not it.
Gets hot and humid in South Carolina too and I have zero issues.

 

Do you have a moonroof?

 

Lemon law. I'm about an hour NE of you. Mine doesn't do that. Get your money back and get something that doesn't do that. Life is too short to be encumbered with such worries. Still, if that is all you have to cause you grief, you have a very Blessed life!

 

Alas, no.

 

Worth a shot. My old ride (2006 Escape) had a moonroof, and I was getting water in the cab, leaking down into the footwells from behind the dash. It would just soak the carpet (pulled out a gallon once with the shop vacuum). Discovered it was clogged moonroof drains. Weed-whacker cord worked wonders clearing the blockage...

 

Yes, I know how thermodynamics and condensation work, and I know that the job of an AC is to both cool and dehumidify the air, as well as how it does that. And the dealership who has tried to solve my problem a couple of times knows all of this even better than I do (presumably) and they have been unable to solve the problem, which is why they have told me that it is functioning as expected. However, I have never had another vehicle that does this.

 

Have you opened a case with Toyota? I really doubt that they would deem water intrusion into the can as "normal". Dealership service centers are notorious for putting off warranty repairs that get fixed with corporate intervention.

 

Did you use a pipe cleaner or blow are through it. A good stout pipe cleaner is the only way to go

 

Both, a couple of times.