One of the deficiencies of the ceiling ducted system is the restrictions that the ductwork places on airflow. On my A/C units, the air flows straight down, then must make a sharp 90 degree turn to flow into the two small ducts. The 90 degree turn and small ducts severely restrict air flow. One way to mitigate the restrictions is to bypass the ducts and blow the cool air straight down from the blower instead of through the duct.
I performed a similar modification to my Ole Mirada and it significantly improved the A/C performance, so I decided to do a similar modification to my Southwind.
WHAT LOUVER TO USE.
I was originally going to use one of the existing ceiling louvers, remove an existing louver then plug the hole with a blank plate. They look very nice, but because of the way they’re constructed, they restrict the airflow. I visited the local big box hardware store and found a nice looking 4×10 louvered vent. I wanted one that could be open/closed and chose one that pointed the air in a couple different directions. When selecting a louver, get one with the least restrictions to air flow. While I was there, I also picked up 4 of the slide on speed nut plates (#10) and 4 #10 screws that are about 2 inches long. These are used to mount the louvered vent to the sheet metal cover.
Although the louver I used doesn’t look as good as I want, it had the least air flow restrictions.
The modification is fairly easy:
- Remove the ceiling cover and the sheet metal duct cover. This should expose the A/C blower exhaust and if you turn the unit on, you can fell what the unrestricted air flow is like coming straight down.
- Cut a 4×10 opening in the sheet metal duct cover. The opening should be centered, and directly under the A/C blower opening. Match the hole opening in the ceiling cover and cut the 4×10 opening into it
- Drill 4 mount holes in the sheet metal cover. Transfer these holes to the louvered vent.
- Slide the four speed nuts onto the sheet metal cover. Install the sheet metal cover.
- I cut a piece of foam to act as a gasket between the sheet metal cover and the ceiling cover.
- Loosely install the ceiling cover, then install the louver using the #10 screws into the speed nuts.
- Snug every thing up and this should be complete.
The louvers can be open to get the maximum air flow, or they can be closed to route the air through the ducting.
Great hack….cheers
Pictures of what you did?
DUH, I failed to link them.. They’re linked now.. Thanks for letting me know about this..
I have this exact same RV. With the poor airflow I found it almost impossible to cool the front while you could hang meat in the bedroom. First I took thin plexiglass and formed a curved panel to help the air flow through the 90 degree turn into the forward duct of both A/C’s. Second I blocked 75% of the rear duct behind both A/C’s. Third I filled the duct forward of the front vent with foam and a piece of plexi angled at 45 degrees so the air would flow out instead of tumbling in the dead end duct. These mods completely solved the flow problem and the two front ducts will blow your hair when driving.
Thanks for reporting back. Airflow through the ducting is horrible, sharp curves, and a lot of restrictions. Anything that can be done to smooth out the airflow is significant.
Completed on the front A/C, works good. Not sure I’ll bother with it on the rear A/C.
The rear A/C unit does a good job and my concern was blowing straight down on the bed. I still might do it.