Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-13-2014, 10:37 AM   #1
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,403
Images: 5
Miscellaneous A/C drips/leaks

A/C drips to the interior have been discussed before, but I need some clarification as well as offer some insights.

1) A/C drips during high ambient humidity situations, as previously discussed, can occur from interior drain trough and hose leaks, as we all know. I had previously sealed and inspected the drain components and had no issue all summer this year and last. I returned from a trip on Sunday and set the A/C on 73* as a thorough interior cleaning was needed. It was in the 80s and very humid. As expected, the A/C (on auto) was running on high for several hours. I noted a drip from the street side filter intake vent, as I had seen in the past. There was no evidence of any leak in the drain system, but the metal u channel which clamps the A/C unit to the roof had water in it. I noticed that it was VERY cold. I have my cold air plenum well sealed with aluminum duct tape, so I know there are no cold air leaks to the intake side of the system. Is it possible that, through conduction, that the u channel gets so cold that these drips are from condensation of very humid intake air? After interior humidity lowers below the low 50s%, I get no more water in this area.

2) As a part of the cleanup, I had to clean the carpets yesterday. Weather had cooled to the 50s last night, but still very humid. And of course after cleaning the carpets the interior humidity was very high. So I set the heat pump to 75* and ran a fan on the floor. This morning, I had a water drip from between the roof and the outside pan under the A/C. I got on a ladder and noted a lot of water around the perimeter of the pan. Drain holes are fully open, as verified with a coat hanger exploration of the holes.

Check me here....during heat pump operation the outside condenser (now the evaporator during HP use) drains into the pan and out the holes at the bottom, right?

I know this means that I need to replace the seal between the roof and the pan, but that's not in the cards right now, due to a bunch of time constraints.
Is it OK, and effective, to run a clean bead of polyurethane sealer around the perimeter of the pan as an intermediate time fix? Of course, being careful not to plug the drain holes. I understand that if a crack has developed in the pan, that I still may have the leak after sealing the perimeter.

Interestingly, I've had no rain leak here?????
__________________

__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 08-13-2014, 11:40 AM   #2
3 Rivet Member
 
teagues's Avatar
 
2008 20' Safari SE
Charlotte , North Carolina
Join Date: Feb 2007
Posts: 133
Quote:
Originally Posted by dznf0g View Post

1) A/C drips during high ambient humidity situations, as previously discussed, can occur from interior drain trough and hose leaks, as we all know. I had previously sealed and inspected the drain components and had no issue all summer this year and last. I returned from a trip on Sunday and set the A/C on 73* as a thorough interior cleaning was needed. It was in the 80s and very humid. As expected, the A/C (on auto) was running on high for several hours. I noted a drip from the street side filter intake vent, as I had seen in the past. There was no evidence of any leak in the drain system, but the metal u channel which clamps the A/C unit to the roof had water in it. I noticed that it was VERY cold. I have my cold air plenum well sealed with aluminum duct tape, so I know there are no cold air leaks to the intake side of the system. Is it possible that, through conduction, that the u channel gets so cold that these drips are from condensation of very humid intake air? After interior humidity lowers below the low 50s%, I get no more water in this area.
Hopefully this is not a waste of your time, but last month we experienced a similar sounding problem in our 20'. When the AC ran continuously for long periods (due to high temps and/or humidity), water would begin to drip in through the filter area. I investigated and found that water had collected in the U channel, as you described, and also in the inside drain pan under the evaporator.

Checking the outside drain outlet, I could see some dripping there, but less than I would have seen in the past. So I concluded that the drain pan was not draining well enough.

Some condensation on the U channel seems plausible, but in my case I think that the drain pan was overflowing into the u channel and then into the coach from there.

Since we were on the road, I was limited in what I could do to fix any drain blockages. Over a couple of days tried a couple of things and saw some improvement, but still did not 100% fix the problem. But along the way I noticed 2 interesting things:

1. While the AC and its fan were running, the outside drain would drip just a little. Right after the AC fan cut off, a gush of water would drain out. My theory is that the fan creates just enough of a vacuum in the area of the drain that it inhibits draining (along with any remaining crud or pinched section in the drain line).

2. When the trailer is just slightly nose-up, level-wise, the AC was much less likely to drip in the cabin. From the little that I could see of it, it looked like the forward edge of the drain pan is lower than the aft edge.

By making sure that we parked slightly nose-up, and setting the thermostat so that the AC would occasionally shut down, we avoided any additional problems for the rest of the trip. And that would have been over two weeks with some very hot and humid days in there.
__________________

__________________
teagues is offline   Reply With Quote
Old 08-13-2014, 11:57 AM   #3
1 Rivet Member
 
geogeczy3's Avatar
 
2007 28' International CCD
2009 27' FB International
Garland , Texas
Join Date: Dec 2011
Posts: 9
This problem is annoying. My teenage son thought it was because we were not level. I scoffed. We went nose up and down with the jack, guess what more down, water, nose up ,no water. Did not have the energy to check tilt left or right.the stove.
__________________
geogeczy3 is offline   Reply With Quote
Old 08-13-2014, 01:01 PM   #4
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,403
Images: 5
Teagues, I think your thought process is right on all accounts. Previously, I too came to the same conclusions you did about the turbulence within the trough. Last year I sealed the upper edges of the trough and sealed the hose bib area. I am now confident that an overflow due to turbulence is not the cause, as all was dry north of the u channel.
It is normal to get a gush when the fan shuts off, and mine will only drip while running. But when it shuts off, I'll get an estimated cup or more run freely out the drain. Today, while working up inside there, I saw and recalled that the u-channels are a stamped part of the entire cold air plenum. So it makes perfect sense that it would get very cold during the cool down run-time of a heat soaked and humid trailer.

It only does it on the street side channel, but the blower "tunnel" is offset to that side as well. I wonder if keeping a length of absorbent material in the channel would be enough to stop dripping of condensate in the channel??? It would dry promptly after humidity drops, being in the intake stream.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 08-13-2014, 01:43 PM   #5
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,403
Images: 5
Also, do all of you have a liberal amount of Tempro or Vulkem up inside around the perimeter of the roof to pan bottom joint.....or is that a feeble attempt by PO to cure a bad seal?
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 08-13-2014, 10:00 PM   #6
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,403
Images: 5
I take back the condensation theory. Found a crack on the bottom of the drain trough about an inch behind the drain tube fitting. About 1.5" long.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 08-14-2014, 10:47 AM   #7
4 Rivet Member
 
2012 30' Classic
Homosassa , Florida
Join Date: Nov 2010
Posts: 452
Now that's some good diagnostic work. Would be hard to find until the you actually see water. Congratulations on sticking to it.
__________________
Tater is offline   Reply With Quote
Old 08-14-2014, 01:50 PM   #8
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,403
Images: 5
I have to install an aux drip cup kit. Been PMing Lewster. I just don't think it will happen this summer though. Too many other things with work and the stick house. In the meantime, I had to "patch" the Vulkem surrounding the roof opening, and apply Eternabond to the drain trough.

I think I'll need help lifting the A/C out to avoid damaging something. Hopefully my temporary fixes will stop the leaks for now.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is offline   Reply With Quote
Old 08-18-2014, 10:38 PM   #9
"Space A" S/O Registry 11
 
2006 34' Classic S/O
Fort Worth , Texas
Join Date: Feb 2007
Posts: 550
My 34' Classic with two A/Cs had a leak onto the bed from the rear A/C during high humidity periods. Nothing was stopped up. It turns out that Dometic had cracked pan trouble back then and built a new modified pan. $500 later for A/C and pan R&R, no more leaks. It was worth it to make the trip to JC and not get wet sleeping. My wife likes it better too!
__________________
guskmg is offline   Reply With Quote
Old 08-18-2014, 11:45 PM   #10
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,279
Quote:
Originally Posted by guskmg View Post
My 34' Classic with two A/Cs had a leak onto the bed from the rear A/C during high humidity periods. Nothing was stopped up. It turns out that Dometic had cracked pan trouble back then and built a new modified pan. $500 later for A/C and pan R&R, no more leaks. It was worth it to make the trip to JC and not get wet sleeping. My wife likes it better too!
Are you referring to the lower metal catch pan at the base of the upper A/C unit's frame or Airstream's proprietary plastic drain pan. I don't recall Dometic having any issues with the drain catchment on any of their units 8 years ago, but I sure know many folks that have had issues with Airstreams plastic drain pan!
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 08-20-2014, 08:03 PM   #11
"Space A" S/O Registry 11
 
2006 34' Classic S/O
Fort Worth , Texas
Join Date: Feb 2007
Posts: 550
The pan that was changed can be seen from the curbside if you step back far enough. It is white and quite obvious and noticeable on the curbside lower rear just under the cover, but above the roof.. I think it is the bottom catch pan and it was cracked and not repairable.
guskmg
__________________

__________________
guskmg is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Leaks, Leaks and more leaks Jim in Pima Leaks - Weatherstrips, Gaskets, Caulks & Sealants 5 12-12-2007 12:23 PM
Leaks, leaks, leaks jeffnjen30 Leaks - Weatherstrips, Gaskets, Caulks & Sealants 8 08-28-2007 12:03 AM
leaks leaks leaks Globie64 Leaks - Weatherstrips, Gaskets, Caulks & Sealants 10 12-31-2005 06:49 PM
Winterizing - Miscellaneous.... Craig Winterizing, Storage, Carports & Covers 30 12-10-2004 08:31 AM
Miscellaneous Questions Unidentified Models jaco Airstream Trailer Forums 9 04-13-2004 09:04 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:14 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.