Sealing air conditioner duct

Thurman · 08-21-2016, 10:59 AM

Last week I read a lengthy post with lots of photos where someone had taken the grill of their A/C unit off to inspect how the ceiling ducts were attached. They found that there was literally no sealing material of any kind where this duct work met the A/C unit. Two days ago I took the grill off of mine and discovered the same thing, no sealing material of any kind. This allowed cold air to blow up into what one may call the attic of the TT, a '15 Coachmen Freedom Express 310 BHDS. I also found that at the ends of each duct run there seemed to be no end. I removed the registers at the ends of each run, ran an electricians fish tape up into the duct work and I could extend it a distance almost equal to the end walls of the camper. I also removed the metal plate that the hold-down bolts for the A/C go through and found that the metal baffle which is to prevent cold air from returning right back into the return air had a 1/2" gap in it. I had to adjust this plate to seal off between the incoming and outgoing air and secure the baffle in place. I took photos but only one came out viewable which is as I found the duct work where it meets the A/C unit. More photos today to share later.

Thurman · 08-21-2016, 08:44 PM

I spent the better part of the day insulating the gaps between the top of the ceiling material and the bottom of the A/C duct at each of six (6) registers in the camper. The gaps between these materials was absolutely pathetic. Cooled air was going not going into the registers, just going into the gaps which sent the air into the attic area. I have no wish to cool the attic area.

**Bama Rambler** · 08-22-2016, 10:57 AM

Good job and thanks a ton for the pics. I guess we're all going to have to double check our units for A/C leaks and insulation.

Thurman · 08-24-2016, 08:33 PM

I shared this info with a friend of mine who has a Jayco TT. He pulled the grill of his A/C and found gaps between his cold air outlet and the duct work. So it's not only an FT problem

SeaDog · 08-24-2016, 08:37 PM

In the long run this will make a difference in your overall comfort good job

SilhouettePenny · 08-24-2016, 08:55 PM

If you can access the back side of your gas heating unit you may find flimsy flexible heat ducts stapled to the duct work, big source of heat loss...better buy another roll of silver cold weather tape.

Also remove the kitchen stove vent if yours goes thru an exterior wall. You might be surprised to see how much moist air is being pushed into the wall cavity. Sometimes you can seal it with caulk, but keep the tape handy just in case.

jbhodj · 08-24-2016, 09:08 PM

Following this as I have a 292bhds.

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jbhodj · 08-24-2016, 09:20 PM

Could you reference the post you read about checking all this duct work? Thanks for sharing as well!! This is an easy project to do which for me is good

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Thurman · 08-25-2016, 08:47 AM

SilhouettePenny: Thanks for that info. After the A/C fiasco I will definitely look into the heating ducts even though in my area of S.W. Ga. heat would be seldom used. At this point I do know that they are the clear type very thin flexible ducts. In the past I have used some 4" flex duct that comes with fiberglass insulation made onto it and I know where to get it, will use that.
jbhodj: I found the original post on this forum somewhere, I know I did. I even showed the post and photos to my g'friend and she remembers seeing it. I have looked again but have not found it. The post was rather long with a lot of good photos of that individual's findings and solutions. As I stated in post #4 a friend of mine found this same problem in his '16 Jayco unit. He also states that he could tell a significant increase in air flow by sealing up the duct work where it meets the A/C unit. How much cooled air is being lost in all the units out there with poor attempts at sealing up this area, or worse not sealing it at all?

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