A/C dripping from condensation?

[69hugger]

This is my first "hotrod" with A/C and I just got back from my first road trip, (about 4 hours each way). It was mid to high 80's and pretty humid.
The A/C worked great, except after an hour or so on the road it started to drip condensate from the outside of the floor vent and A/C housing onto the passenger floor and later dripped from under the dash onto my feet. The dripping was substantial. My wife had to cover her feet with a towel to keep them & the carpet dry. I was also worried about my stereo unit getting ruined, and this maybe even causing an electrical short.
The dripping doesn't occur when driving the 10 to 40 miles I normally drive the car. But I will almost always see vapor condense on the center dash vent.

On a scale of 1-10, this is a "3" of concern to me.

I called V-A & they said it is simply a function of the air temp differential, and is "normal". I have never experienced this in any other A/C'd car, although they weren't black cars with aftermarket air.

The normal condensation drain is not leaking inside the car and is working fine as best I can tell.

Have you experienced this? Ever heard of it?
Do you worry enough about it to fix it? Maybe insulate the ducts?

Any experience shared is appreciated.

Bill

[Revved]

I've got something similar happening with a vehicle in the shop right now with a Vintage Air System. Driving on surface streets with stop and go traffic there is no issue, but extended highway driving (45min+) it starts getting condensation dripping out of the evap case inside the vehicle. I've already verified the evaporator case drain is clear and I get normal condensation drip with normal driving. My guess at this point is that the evaporator is icing up and blocking the evaporator case drain. The car is apart right now for other work so I haven't been able to test my theory yet by playing with the blend and adding some heat into the case to see if it keep sit defrosted.

Try adding a little heat on your blend to see if it helps. These systems run a heater bypass valve to keep hot coolant out of the evaporator case when on full cold so the A/C blows colder...but it could be getting too cold.

If I remember my A/C theory propoperly an overcharged system could also cause an evaporator to ice up. Most of my experience before the pro-touring work was with fixed orifice tube systems rather than expansion valves as all of these aftermarket systems seem to be.

[69hugger]

I've got something similar happening with a vehicle in the shop right now with a Vintage Air System. Driving on surface streets with stop and go traffic there is no issue, but extended highway driving (45min+) it starts getting condensation dripping out of the evap case inside the vehicle. I've already verified the evaporator case drain is clear and I get normal condensation drip with normal driving. My guess at this point is that the evaporator is icing up and blocking the evaporator case drain. The car is apart right now for other work so I haven't been able to test my theory yet by playing with the blend and adding some heat into the case to see if it keep sit defrosted.

Try adding a little heat on your blend to see if it helps. These systems run a heater bypass valve to keep hot coolant out of the evaporator case when on full cold so the A/C blows colder...but it could be getting too cold.

If I remember my A/C theory propoperly an overcharged system could also cause an evaporator to ice up. Most of my experience before the pro-touring work was with fixed orifice tube systems rather than expansion valves as all of these aftermarket systems seem to be.

Sean,
Mine was definitely freezing up last summer, as it would slowly drip from the drain for hours after I shut it off after driving with the A/C. But I opened the system last winter, and had it charged with the correct amount of 134 (1.4# if I remember) by a shop this spring. It shouldn't be freezing up, but who knows? I was thinking about it freezing, but didn't know how that would lead to the dripping. If anything, it should start blowing warmer as you lose airflow over the evaporator from the ice formation.
Funny you mention adding heat. I wondered about that too, so I questioned V/A about it. They said not to do so. It would not help, and would simply hinder the performance of the system.
It makes me a little less concerned than thinking mine is the only one doing this, but I am still not comfortable with water dripping on electrical stuff & stereo equipment.

Anyone else ever fixed this?

Bill

[ProTouring442]

The evaporator is likely not icing up, as that would restrict the airflow through the evaporator and cause warm air to blow out of the vents.

A couple things come to mind:

Ensure the drain is clear, and that it is at the lowest portion of the evaporator case.

If water is condensing on the outside of the ducts, try wrapping them with insulation.

Metal outlets will usually have condensation and dripping (this was common on cars "back in the day"). There isn't much that can be done about this.

One thing that can help is, once the temperature in the car is where you want it, leave the fan on a medium setting and increase the temperature setting.

Insulating the under dash area (including hush panels under the dash) can help reduce condensation.

[Vince@Meanstreets]

VTA gives you a little strip of tar like paper. I had to cover all the metal sections of the interior tubing. Mainly the high side. I've used Dynamat and home depot stick on foam insulation too.

Never had it come from the vents though.

[dhutton]

Did you seal all the vents and holes in the firewall? It sounds to me like you have a lot of outside air leaking into the car.

Don

[69hugger]

Thanks for the suggestions. I will look for air leaking (maybe the kick panel vents are open) and try some duct insulation if there is room. But it is very tight under the dash.

I don't have any more long trips scheduled for this summer, so it shouldn't be a big issue for a while.

Bill

[dhutton]

Thanks for the suggestions. I will look for air leaking (maybe the kick panel vents are open) and try some duct insulation if there is room. But it is very tight under the dash.

I don't have any more long trips scheduled for this summer, so it shouldn't be a big issue for a while.

Bill

Aren't the kick panel and dash vents supposed to be sealed off? At least that is my recollection.

Don

[Tim john---]

Speaking of air/cabin leaks: What about A/C in a convertible, air on with the top down. Is that going to create a condensate problem ?

Tim john---

[MarkM66]

Speaking of air/cabin leaks: What about A/C in a convertible, air on with the top down. Is that going to create a condensate problem ?

Tim john---

It shouldn't matter. Condensation is suppose to drain out like it should.

For OP, call Vintage Air, and get their answer.

[dhutton]

It shouldn't matter. Condensation is suppose to drain out like it should.

For OP, call Vintage Air, and get their answer.

From the OP's original post:

I called V-A & they said it is simply a function of the air temp differential, and is "normal". I have never experienced this in any other A/C'd car, although they weren't black cars with aftermarket air.

Don

[Revved]

On the vehicle I'm dealing with the water is not coming out of the vents but dripping from the evap case like the drain isn't big enough. I have already verified the drain is clear and as mentioned am getting normal water draining with normal driving. Our humidity has been really high this year so I suppose it is possible that I'm getting so much condensation it is over flowing the drain.

Or another random Idea I just thought of.... Where is your A/C drain located? Mine just has a 1/2" aluminum tubing stub a few inches out of the firewall going down... In theory it could be possible that at highway speeds there is a high pressure area at the back of the engine bay not allowing the condensation to drain properly. I may try extending my drain down under the car where again in theory it would create suction by the air passing under the car.

True that icing of the evap would cause a degredation of the cooling from the vents which I'm not getting but the car I'm dealing with is a convertible so you are never really cooling off like a full cabin car so for me it's hard to tell if I'm loosing cooling... need to get a battery in my dash temp gauge I haven't used in 10 yrs.

[Chevy Kid]

I had the same problem with my VA a couple years ago on a trip from California to Goodguys Colombus. Talked to them at the show and they nodded. They said this sometimes happens in conditions where the a/c is at max for extended lengths. We ran it hard for 5 straight days.

I don't normally see it otherwise. Where we live is not humid though like back east.

Tim

[Vince@Meanstreets]

On the vehicle I'm dealing with the water is not coming out of the vents but dripping from the evap case like the drain isn't big enough. I have already verified the drain is clear and as mentioned am getting normal water draining with normal driving. Our humidity has been really high this year so I suppose it is possible that I'm getting so much condensation it is over flowing the drain.

Or another random Idea I just thought of.... Where is your A/C drain located? Mine just has a 1/2" aluminum tubing stub a few inches out of the firewall going down... In theory it could be possible that at highway speeds there is a high pressure area at the back of the engine bay not allowing the condensation to drain properly. I may try extending my drain down under the car where again in theory it would create suction by the air passing under the car.

True that icing of the evap would cause a degredation of the cooling from the vents which I'm not getting but the car I'm dealing with is a convertible so you are never really cooling off like a full cabin car so for me it's hard to tell if I'm loosing cooling... need to get a battery in my dash temp gauge I haven't used in 10 yrs.

Good point.

Maybe I have never had an issue because I drain out to the side cowl vent (high suction area) and always have a down hill run on the line.

[Rob Ruthless]

This is my first "hotrod" with A/C and I just got back from my first road trip, (about 4 hours each way). It was mid to high 80's and pretty humid.
The A/C worked great, except after an hour or so on the road it started to drip condensate from the outside of the floor vent and A/C housing onto the passenger floor and later dripped from under the dash onto my feet. The dripping was substantial. My wife had to cover her feet with a towel to keep them & the carpet dry. I was also worried about my stereo unit getting ruined, and this maybe even causing an electrical short.
The dripping doesn't occur when driving the 10 to 40 miles I normally drive the car. But I will almost always see vapor condense on the center dash vent.

On a scale of 1-10, this is a "3" of concern to me.

I called V-A & they said it is simply a function of the air temp differential, and is "normal". I have never experienced this in any other A/C'd car, although they weren't black cars with aftermarket air.

The normal condensation drain is not leaking inside the car and is working fine as best I can tell.

Have you experienced this? Ever heard of it?
Do you worry enough about it to fix it? Maybe insulate the ducts?

Any experience shared is appreciated.

Bill

69hugger,
Sorry you are having issues with your a/c system. You should be concerned; condensation dripping inside your interior is NOT normal. There are 3 reasons why this may have happen to you.

1. There is a crack or a hole in your evaporator. Water always follows the path of least resistance.
2. The hose connection to your evaporator is loose or not connected properly.

If neither of these are the case then you can message me and I will tell you the only thing left it could be.

[kwhizz]

I would think that the dripping would come from the condensation of humid air (these cars aren't sealed as tight as new cars) on the flexible plastic A/C hoses that have the cold air blowing thru them......the water condenses on the hose and drips off at the lowest point of the hose as routed behind the Dash.........Just my $.02

Ken

[ProTouring442]

Speaking of air/cabin leaks: What about A/C in a convertible, air on with the top down. Is that going to create a condensate problem ?

Tim john---

You'll get condensation at the outlets, especially if they are made of metal (assuming you have the A/C on and the top down on a humid day).

[69hugger]

To clarify, this is not condensation leaking from the inside of the case, but forming on the outside of the case and cooling ducts.
I double checked my drain. It is not leaking inside the car.
The drain fitting on the case had been cracked & repaired before I bought the car, and I bumped & cracked the outlet repair again during my rebuild last winter, but repaired it very securely with epoxy putty. The drain hose is 3/8 ID fuel line, and I can blow easily through it when I disconnect it at the case filling. The line runs slightly downhill to the front of the kick panel, then down through the rocker, exiting behind the front tire.
I also connected another piece of hose to the fitting & blew through it to verify it is not plugged.
The unit is a V/A Gen II Compact system.
As it was still dripping yesterday (36 hours after last use), it is obviously freezing up during extended use.
I think it only makes sense to try to eliminate or minimize the freezeup. I know improper R-134 level can cause that. Does anything else cause freezeup?
It was properly filled to V-A spec. (1.8#) a couple months ago.

They also publish the following specs...
I will get these checked next.

High-side Pressures:
160 to 270 PSI.
NOTE: General rule of thumb is two times the ambient (daytime) temperature, plus 15 to 20%.
Low-side Pressures:
10 to 20 PSI in a steady state.
Center Duct Temperature:
36 ̊F to 46 ̊F.

I will report if these are still in spec...

Thanks to all for weighing in!

Bill

[dhutton]

To clarify, this is not condensation leaking from the inside of the case, but forming on the outside of the case and cooling ducts.
I double checked my drain. It is not leaking inside the car.
The drain fitting on the case had been cracked & repaired before I bought the car, and I bumped & cracked the outlet repair again during my rebuild last winter, but repaired it very securely with epoxy putty. The drain hose is 3/8 ID fuel line, and I can blow easily through it when I disconnect it at the case filling. The line runs slightly downhill to the front of the kick panel, then down through the rocker, exiting behind the front tire.
I also connected another piece of hose to the fitting & blew through it to verify it is not plugged.
The unit is a V/A Gen II Compact system.
As it was still dripping yesterday (36 hours after last use), it is obviously freezing up during extended use.
I think it only makes sense to try to eliminate or minimize the freezeup. I know improper R-134 level can cause that. Does anything else cause freezeup?
It was properly filled to V-A spec. (1.8#) a couple months ago.

They also publish the following specs...
I will get these checked next.

High-side Pressures:
160 to 270 PSI.
NOTE: General rule of thumb is two times the ambient (daytime) temperature, plus 15 to 20%.
Low-side Pressures:
10 to 20 PSI in a steady state.
Center Duct Temperature:
36 ̊F to 46 ̊F.

I will report if these are still in spec...

Thanks to all for weighing in!

Bill

I think the VA controller uses a thermistor to monitor the evaporator temperature and turns on the heat when it gets close to freezing. Is your heater control valve working properly?

Don

[GrabberGT]

I would think that the dripping would come from the condensation of humid air (these cars aren't sealed as tight as new cars) on the flexible plastic A/C hoses that have the cold air blowing thru them......the water condenses on the hose and drips off at the lowest point of the hose as routed behind the Dash.........Just my $.02

Ken

I just had my system charged for the first time ever and this was my experience as well. Getting a few drips from the vent tubes while cruising down the hwy. My wife was more alarmed than I was.

[69hugger]

I think the VA controller uses a thermistor to monitor the evaporator temperature and turns on the heat when it gets close to freezing. Is your heater control valve working properly?

Don

Mine is a Gen 2. Maybe it isn't as advanced as the gen 4 systems?
I asked the tech at V/A about using heat as a method to control it & he said it wouldn't help, and would just counteract the A/C, making it less effective.
But, yes, my heat works fine.

Bill

[dontlifttoshift]

With the gen II units, freeze up is much more common. A compac is on the small side for that car.

There is a capillary tube in the top of the case and that is what controls the cold temp. If you are running the AC setting at max cold it will freeze up. If your cowl/firewall is not insulated the unit will sweat just like a cold can of soda would sitting in the cupholder.

Someone mentioned it before, don't dial back the fan speed, dial back the thermostat a touch. Stuff a thermometer in the dash vent and run the AC. Set the AC thermostat so that it runs about 38-40 degrees and it should not freeze up.

[hifi875]

^^^^ is correct. turn thermostat back just a tad. it wont freeze up but it will still sweat.

[FlameBroiled]

I just took my first real test drive in my customers 67 LS7 with VA, 45 min with the AC on low but maxed on the temp setting. And the same thing happened to its box, sweating like a fat guy standing still.....

So far I have had nothing but problems with the VA and this will be the last one I plan to install. Anyone else have problems with the fan speed switch going to high speed when turning it off?? I have VA on speed dial and have replaced most of the components. I am getting tired of tearing out the interior just to try the next suggested fix..... fan switch, Ecu, and heater valve... whats next?

[69hugger]

I just took my first real test drive in my customers 67 LS7 with VA, 45 min with the AC on low but maxed on the temp setting. And the same thing happened to its box, sweating like a fat guy standing still.....

So far I have had nothing but problems with the VA and this will be the last one I plan to install. Anyone else have problems with the fan speed switch going to high speed when turning it off?? I have VA on speed dial and have replaced most of the components. I am getting tired of tearing out the interior just to try the next suggested fix..... fan switch, Ecu, and heater valve... whats next?


HEY!! Lay off us fat guys!

:hitaxeonthehead:


Bill

[69hugger]

With the gen II units, freeze up is much more common. A compac is on the small side for that car.

There is a capillary tube in the top of the case and that is what controls the cold temp. If you are running the AC setting at max cold it will freeze up. If your cowl/firewall is not insulated the unit will sweat just like a cold can of soda would sitting in the cupholder.

Someone mentioned it before, don't dial back the fan speed, dial back the thermostat a touch. Stuff a thermometer in the dash vent and run the AC. Set the AC thermostat so that it runs about 38-40 degrees and it should not freeze up.

Thanks Donny. I will try your suggestions.


Bill

[rkleypas]

I have a 70 Chevelle convertible with a Gen 4 VA system. We did the Hot Rod Power tour and experienced the same thing. Water dripping all over the carpet from the ducts and the evap case sweating like crazy. VA told me the same thing about the soda can. I'm going to try wrapping the ducts with black foam tape from Home depot and place worm screw clamps on the evap case ducts. Doing this tomorrow, so I'll let you know. I dont want to have a moldy smelling car.

[GregWeld]

Gwen's Brizio built '33 Ford has a VA unit and was doing this exact same thing. On our first trip from San Francisco to LA - it was pouring water out from under the dash. Brizio found the unit to be holding water due to the case and faulty drip tube (the factory - not Brizio's installation) issue. They fixed this and the problem was solved.

Her car is a convertible - and we just drove the car from SF to Austin Texas.... with the A/C blowing the whole time... When it got really humid we had one or two drip from under the dash - but not the water that WAS coming from the unit as described above. I would say it was normal and only happened once. I then turned the temp knob down just a bit - and it didn't happen again - and the cabin stayed cool.

I've had other cars with Vintage Air systems for years - and have taken them on long trips and NEVER had this happen. I think there's something that has changed or gone wrong with their units "recently"...It was implied to me that this was the second or third unit recently with this same "defect" that had to be remedied.










69hugger,
Sorry you are having issues with your a/c system. You should be concerned; condensation dripping inside your interior is NOT normal. There are 3 reasons why this may have happen to you.

1. There is a crack or a hole in your evaporator. Water always follows the path of least resistance.
2. The hose connection to your evaporator is loose or not connected properly.

If neither of these are the case then you can message me and I will tell you the only thing left it could be.

[dhutton]

I sent the engineering manager of VA a PM with a link to this thread over on the other forum. Let's see if he replies.

Don

[rkleypas]

Greg,

What did they do to remedy the problem? I didn't get around to my proposed repair today and may want to hold off on my "engineering" until I find out how they fixed the problem. Thanks

[GregWeld]

Greg,

What did they do to remedy the problem? I didn't get around to my proposed repair today and may want to hold off on my "engineering" until I find out how they fixed the problem. Thanks



I wish I knew - because I could share with you, but I have no clue what they did.

[69hugger]

Greg,
Any chance you can find out from Brizio?
Did they perhaps...
Re-engineer the drain port (maybe drill & tap a new one in a different location in the case)? Or maybe add another drain on the other side of the case & T them together?
Or make an adjustment in the controls so it doesn't operate as cold when turned to the coldest setting?
Or, add or remove R-134 so the evap level is different?
Or, have to remove & open the unit to ???

I hope not the latter.


Thanks to all for their feedback.


Bill

[GregWeld]

I've sent an email asking if he cares to share.....







Greg,
Any chance you can find out from Brizio?
Did they perhaps...
Re-engineer the drain port (maybe drill & tap a new one in a different location in the case)? Or maybe add another drain on the other side of the case & T them together?
Or make an adjustment in the controls so it doesn't operate as cold when turned to the coldest setting?
Or, add or remove R-134 so the evap level is different?
Or, have to remove & open the unit to ???

I hope not the latter.


Thanks to all for their feedback.


Bill

[GregWeld]

Greg,
Any chance you can find out from Brizio?
Did they perhaps...
Re-engineer the drain port (maybe drill & tap a new one in a different location in the case)? Or maybe add another drain on the other side of the case & T them together?
Or make an adjustment in the controls so it doesn't operate as cold when turned to the coldest setting?
Or, add or remove R-134 so the evap level is different?
Or, have to remove & open the unit to ???

I hope not the latter.


Thanks to all for their feedback.


Bill



There are three outlets on top of you’re a/c unit. For one we did not have a hose in the center one and it was blowing cold air straight out so we added the hose. Second we had to add more insulation to the brass fittings on the side of the unit, they get so cold they frost up a lot. Hope this helps him.

[69hugger]

Thanks for checking, Greg. I will add the fittings to my check list.


Bill

[rkleypas]

Thanks Greg. I have one of my ports duct taped closed. I'm adding one of the lap vents on the passenger side of the car so maybe that will help get rid of some of the condensation. I'll let you all know if any of my "engineering" works.

[KUL FIR CHICK N]

I sent the engineering manager of VA a PM with a link to this thread over on the other forum. Let's see if he replies.

Don

Hi Guys,

Sorry for my delay in seeing this post. Don sent the PM to me over on PT.com and I didn't have it set to email me when I received a new PM, so I didn't see it until I went on there this morning. It's fixed now so I should be able to respond to PMs in a timely manner.

There are several different issues being discussed on this thread, so I'll work to address them all one at a time.

First, Bill’s issue, as I understand it, is excessive condensation dripping from the EXTERIOR surfaces of the case, duct hoses, and possibly the refrigerant hoses. If, in fact, the condensate is dripping from the exterior of the system, this is not a system-related or defective-system issue. I wouldn't say it's necessarily "normal" either. It's just physics, and it's correctable. If I were troubleshooting your car in person, I'd start by looking for body leakage. The sweating issue you describe is the result of a constant supply of humid, outside air entering the vehicle while you drive. If the cabin is well sealed, with no outside air leakage, the A/C system will quickly dehumidify the air within the cabin, lowering the dew point to a level where there will be little to no condensation observed. I took some quick measurements this morning on one of our test cars so that I could describe this in detail. The ambient temperature this morning in San Antonio was about 85 degrees, and the dew point outside was about 70 degrees. With a dew point of 70 degrees, any surface that has a temperature of less than 70 degrees has the potential to condense water from the air. The further away from 70 the surface is (to the cold side), the faster condensate will form on the surface, just like it does on a soda can, as was described earlier in the thread.

Now, if I step into my vehicle, which has been sitting for several hours with the doors open, the dew point and temperature inside the car will be similar to the outside conditions. I close the doors, start the engine, and run the A/C on full power with the windows up. The dew point inside the car will immediately start to drop, and within about five minutes, the dew point inside the car will be around 45-50 degrees. The temperature of the air exiting the vents will be in the neighborhood of 40 degrees, and the exterior surfaces of the case and ducts will be in the neighborhood of 45-50 degrees. In this case, I would not expect to see any condensate form on the case and duct surfaces, no matter how long I wait. If I open the windows, the dew point inside the car will immediately start to rise, and condensation will begin to form on the cold duct and case surfaces. The air leaving the A/C vents is 40 degrees and has a dew point of 35 degrees, but the constant supply of humid outside air is mixing with the conditioned cabin air, raising both the temperature and the humidity in the cabin.

The fix for Bill, 69hugger’s condensation problem is probably going to be sealing up the kick panel vents, door and window seals, any holes in the firewall, sealing the shifter boot, and even the trunk seals. If the trunk seals are leaking, the low pressure at the rear of the car will draw air out through the trunk, which will cause negative pressure in the cabin, and draw outside air in through every crack and crevice in the body. The aforementioned insulation of the ducts and case would help, but it is more of a Band-Aid, masking the root problem. One thing that MUST be insulated is the suction line inside the cabin. All exposed metal surfaces of the suction line should be wrapped with "press tape" as supplied with all of our kits. The suction line can often run at or below freezing, and exposed portions of it will sweat profusely.

Please feel free to PM me, and I’ll do my best to help you correct this issue.

Respectfully,

Ryan Zwicker
Director of Engineering
Vintage Air, Inc.

[GregWeld]

NEW cars never have these condensation issues... or dripping.

[KUL FIR CHICK N]

NEW cars never have these condensation issues... or dripping.

Nope, they're sealed. Drive for an hour or two in your new car with the windows cracked on a humid day and it'll be dripping too. But who wants to be driving their new car? That's why we're all here, right?

[KUL FIR CHICK N]

Mine is a Gen 2. Maybe it isn't as advanced as the gen 4 systems?
I asked the tech at V/A about using heat as a method to control it & he said it wouldn't help, and would just counteract the A/C, making it less effective.
But, yes, my heat works fine.

Bill

The Gen II ComPac uses an adjustable mechanical thermostat. On its max cold setting, it will cycle the compressor when the probe, positioned in the coldest part of the evaporator coil, reads 28 degrees. If you run the system for an extended period of time at max cold, it will eventually freeze up the evaporator. VA recommends moving the thermostat about 1/8 of its travel off of the coldest position. If you're in Phoenix, you can probably get away with running it max cold, but if you are in Houston, back off a bit.

The Gen IV systems that most of VA's SureFit systems are based on have a thermistor probe and the controller is programmed to cycle the compressor when the probe senses 34 degrees.

Ryan

[GregWeld]

Nope, they're sealed. Drive for an hour or two in your new car with the windows cracked on a humid day and it'll be dripping too. But who wants to be driving their new car? That's why we're all here, right?



Totally agree! And this is a good education for all of us!

[KUL FIR CHICK N]

On the vehicle I'm dealing with the water is not coming out of the vents but dripping from the evap case like the drain isn't big enough. I have already verified the drain is clear and as mentioned am getting normal water draining with normal driving. Our humidity has been really high this year so I suppose it is possible that I'm getting so much condensation it is over flowing the drain.

Or another random Idea I just thought of.... Where is your A/C drain located? Mine just has a 1/2" aluminum tubing stub a few inches out of the firewall going down... In theory it could be possible that at highway speeds there is a high pressure area at the back of the engine bay not allowing the condensation to drain properly. I may try extending my drain down under the car where again in theory it would create suction by the air passing under the car.

True that icing of the evap would cause a degredation of the cooling from the vents which I'm not getting but the car I'm dealing with is a convertible so you are never really cooling off like a full cabin car so for me it's hard to tell if I'm loosing cooling... need to get a battery in my dash temp gauge I haven't used in 10 yrs.

Ram-air and/or drain placed in a high pressure area can definitely lead to drainage problems. Running the hose down out of the pressurized under-hood area will help.

The fact that you're working on a convertible could be part of the problem. They never seal well and you'll be producing more condensate both inside and outside the case than you would in a hard top. For this vehicle, insulating the duct hoses may be worth the effort.

Ryan

[69hugger]

Ryan,
Thanks for the replies.

I think you're right on track...my car is not that well sealed. The windows need some adjustment, and I noticed today some warm air coming through the shifter boot. I'm not sure about the kick panel vents, as they have speakers in them.... but I'll take it apart this winter to check that all out. I think my trunk may have even been a contributor, but think that is corrected now.
I have noticed (as you and others have suggested) that having the temp slider at halfway or so seems to keep it from freezing up. When I operated it at max cold, it was obviously freezing up as it would drip for hours. Now, it stops dripping within minutes after stopping.

I'll chip away at all this 'til it's right.

Thanks again to all for weighing in.


Bill