Thoughs on rooftop air conditioner ducting

[Fugitive861]

My ac is ducted and it seems even though there are more forward vents more air blows to the rear. So I removed the ducting to see how it was set up. I was disturbed to find that although the coach has a ten inch wide duct running the length of the coach, the duct feeding forward is only 6 inches. That explains why less air is blowing forward. I would like to make a new plenum to match the 10 inch wide duct but my concerns are that the return air would then be a much smaller opening. Thoughts on widening the forward plenum reducing return air chase?



I would also like to have a dump vent immediately below the ac. I am not sure what ceiling assembly would work properly. It's a Coleman Mach 13,500. Any assistance there would be appreciated as well.

[Ivylog]

I didn’t know there was a return air duct. Where is the return air filter located?

[Tuscany]

That is not a return air duct. The return air goes directly into the front faceplate through the filter.

[Domo]

OP:

Looks like a good project!

Could you kindly include make/model/year of your MH in your signature. It will help others that wish to follow or comment.

Thanks!

[Alan_Hepburn]

Originally Posted by Fugitive861

I would also like to have a dump vent immediately below the ac.

Doesn't the AC unit have vents on the ceiling plate already? On ours we can open some vents for quick localized cooling, or close them for more airflow into the ductwork.

[asuperheat]

Originally Posted by Tuscany

That is not a return air duct. The return air goes directly into the front faceplate through the filter.

Depends on the RV, Mine has ducted returns and supply.

Not sure what RV you have and if it is a ducted return or not but it is probably not a good idea to restrict the return. Probably better to restrict the supply to the back some to push more air forward but not to much. The other thing you could maybe do is replace the vents with something adjustable in the back.
Dealing with the windshield heat would probably have the biggest effect. I would start there. Magneshade or Reflectix maybe.