Access A/C ducts?

[Rainsmik]

I see from this fourum that it is not uncommon for a/c ducts to be crushed to the point that air is restricted/blocked. I would like to check mine. How to you get to them? From the vents seems like very little would be accessible and from the roof seems like a major project.

[jcurtis934]

You can't without dropping individual panels of the inside ceiling! What you can do is take covers off the inside ac out vents and take a picture looking both ways to see what the condition of both ducts are. To remove a cover, insert a small flat bladed screwdriver under the cover nearby where you see an indent in the cover. There are three of these plies and you will hear it click when you pry it apart at each spot or maybe not. Even if you find something, it will be a major project to pull down the ceiling to fix something.

[Rainsmik]

Originally Posted by jcurtis934

You can't without dropping individual panels of the inside ceiling! What you can do is take covers off the inside ac out vents and take a picture looking both ways to see what the condition of both ducts are. To remove a cover, insert a small flat bladed screwdriver under the cover nearby where you see an indent in the cover. There are three of these plies and you will hear it click when you pry it apart at each spot or maybe not. Even if you find something, it will be a major project to pull down the ceiling to fix something.

Thank you very much. Past quotes made it sound much easier than I could imagine.

[DQDick]

If you haven't taken those covers off you have another issue also. There are filters behind those covers that need to be washed and replaced in our case at least every two weeks.

[twindman]

I think there are 2 things to do and both are pretty easy as far as I can tell. First, when you take the vent off, see if it has a inch or more plastic circling around the vent. If so saw off a good portion of it. As the air moves along the duct work, these inhibit the flow.
The other thing I have not done but read about is some duct work collapses. So people take pvc and I assume cut into short lengths so they will slide into the ducts. Then connect them with joints and slide them along. This holds the duct work open. Search for details as to the size of the pvc, etc on here.

[Rainsmik]

Originally Posted by DQDick

If you haven't taken those covers off you have another issue also. There are filters behind those covers that need to be washed and replaced in our case at least every two weeks.

More good info. That is more frequent than I thought necessary. Will add that to my to do list and schedule. Thanks.

[Rainsmik]

Originally Posted by twindman

I think there are 2 things to do and both are pretty easy as far as I can tell. First, when you take the vent off, see if it has a inch or more plastic circling around the vent. If so saw off a good portion of it. As the air moves along the duct work, these inhibit the flow.
The other thing I have not done but read about is some duct work collapses. So people take pvc and I assume cut into short lengths so they will slide into the ducts. Then connect them with joints and slide them along. This holds the duct work open. Search for details as to the size of the pvc, etc on here.

I am hoping I don't have a problem but that sounds like a great solution. Thank you.

[richfaa]

My main observation at the factory tour when at the fall rally will be to try to determine how the ducts get crushed.

[Baldicon]

They were supposed to start installing "new and improved" ductwork Fall 2018 to eliminate the crushing problem. We just took delivery of a 2019 3121, and no air flow/cooling problems so far. Keeping fingers crossed.

[richfaa]

Originally Posted by Baldicon

They were supposed to start installing "new and improved" ductwork Fall 2018 to eliminate the crushing problem. We just took delivery of a 2019 3121, and no air flow/cooling problems so far. Keeping fingers crossed.

We will confirm that at the fall rally. Thanks for the update.

[gary s swenson]

I used a 1 1/4 pvc cut to fit parallel to the return opening, then after inserting it into the opening, I rotated it 90 degrees in the duck work. It opened up the duck significantly. I did all the returns on each unit. It did give us a lot more air flow and better cooling. Very easy fix to do. I was very carefull when rotating the pvc so as not to damage the duck. Good luck.

[richfaa]

We did not have a problem with our 2013 3402 Big Sky good airflow and proper cooling. We did cut the necks off the A/C ducts.

[RKassl]

Originally Posted by DQDick

If you haven't taken those covers off you have another issue also. There are filters behind those covers that need to be washed and replaced in our case at least every two weeks.

Are you saying that behind the round A/C that blow out the cooled air their are washable filters? I know that in our 2015 behind the two square inlet ducts there are filters.

[DQDick]

Originally Posted by RKassl

Are you saying that behind the round A/C that blow out the cooled air their are washable filters? I know that in our 2015 behind the two square inlet ducts there are filters.

No, I was talking about the square ones. While were on the subject of the supply ducts however, here are a couple of things to look at. First some folks have found when they took them off (three tabs on the cover) that tape and other stuff could be blocking them. Even if you have none of that you will find the the base extends way into the duct work blocking the air flow. Many of us have taken those out (three screws) and trimed them to fit so they don't restrict the flow. Then to go a step further, some of us have cut every other fin off the cover to let more air out. In my case I did that to most of them except for several that I wanted to restrict and direct the flow more.

[phillyg]

Harbor Freight has a relatively inexpensive inspection camera for $75. I don't know how effective it is. I suspect you might find a tool rental place that rents out a good quality camera you can run up the ducting.

[Shovelhead]

I bought a WiFi endoscope in line for $25

[fuquatj]

I bought my 3921FB new last year and encountered a somewhat different problem with A/C airflow. First camping trip to Florida from Tennessee in March of 2017, the outside temp got to about 85 and we noticed the camper was not really cool inside even with both units running. Had a local RV repair guy check to find the units were working properly (intake air temp vs. air exiting the vents were within proper range). The dealer had told me that the camper was wired for a third A/C when I bought it, so I attributed the heat to the fact that the camper was large enough to need the third air. I bit the $1600 bullet and had the third air installed. More camping throughout 2017 (with higher outside temps)....same result. I took the camper to the dealer after each camping trip to have them try and figure out what the problem was (in addition to many other issues). They checked and rechecked the units, checked the ducts for crushing, etc. We made a 6 week road trip to Canada in July and August during which the temps weren't bad, but humidity at times was high. We were cool enough inside during the trip, but due to the humidity the entire ceiling would have condensation hanging from it. I made pictures and took it to the dealer once again when we got home. This time they finally figured out the problem. They took the two original units off the camper, and evidently there is a "box" (for lack of a better term) directly below the units to which the ducts are attached. The cool air flows from the unit, into the box, then thru the ducts. The ducts had not been sealed to the box at the factory, therefore most of the cold air was just blowing out into the ceiling. They sealed these with tape and problem solved. Just another example of extremely poor QC at Keystone.

[DQDick]

Yes, some folks have reported that as a problem also. I had mine checked and retaped under warranty.

[jeffba]

Interesting. The repair guy who said you had proper air flow was wrong and cost you $1600. I would circle back with him.

[fuquatj]

Well, I will have to take the hit on that one. I can't say that the dealer advised me that the third A/C would solve the problem. They just told me it was wired for 3, and it was my idea to get it. If it gets really hot, running all 3 keeps it nice and cool.