Roof AC: Ducted or Not
Posted: Sat Mar 09, 2019 5:29 pmI am stirring out of winter lethargy on my trailer conversion and wanted to ask the crowd here a quick question.
I have installed a Roof AC on a 24' trailer. The interior portion can either be ducted or non-ducted. I have not yet done the interior ceiling so I have options -- all I've done thus far is jam 1" of polyiso foam between the rafters. The layout will have a bedroom up front with interior walls separating it from the living space aft (where the AC unit will be).
If non-ducted, its pretty easy: put some furring strips into the ceiling rafters, stuff the empty space with insulation, and put in a non-ducted grille. The concern here is that the front bedroom area may get inadequete cooling from the AC unit. I could mitigate that with a fan or something, or perhaps a small bit of conduit with an in-line fan to bring air forward from the rear area to the bedroom behind a small soffit wall or trim for additional ventilation.
If I go ducted, then I can run ducts to the forward bedroom of the trailer as well as one to the rear bunkbed space, which should improve the camping experience in severe heat quite a bit. The best plan I've developed is a drop ceiling: 3.5" for the rectangular duct register, then 3.5" for 2x4 joists going across the trailer, then another 1" for strapping running fore-and-aft. That is ~8 vertical inches tied up with a drop ceiling. I can put some foam insulation in there but its a lot of space that could be used for cabinets and such up high. Installing the drop ceiling will be a bit of a PITA.
The overall trailer is 88" interior height, so I do have sufficient space for a comfortable living area even with the drop ceiling.
One final factor -- I have a smaller AC unit (powersaver model) that can be run on a 2K generator. So ducting may make the most of a limited AC source, and a few more inches of insulation in the ceiling is never bad.
Based on reading what people in "normal" camper trailers say, ducted is 100% the way to go with a trailer this size. Giving up 9" of interior vertical space that could be used for wall cabinets, shelves, bunk beds, etc seems like a lot though.
Thoughts?
I have installed a Roof AC on a 24' trailer. The interior portion can either be ducted or non-ducted. I have not yet done the interior ceiling so I have options -- all I've done thus far is jam 1" of polyiso foam between the rafters. The layout will have a bedroom up front with interior walls separating it from the living space aft (where the AC unit will be).
If non-ducted, its pretty easy: put some furring strips into the ceiling rafters, stuff the empty space with insulation, and put in a non-ducted grille. The concern here is that the front bedroom area may get inadequete cooling from the AC unit. I could mitigate that with a fan or something, or perhaps a small bit of conduit with an in-line fan to bring air forward from the rear area to the bedroom behind a small soffit wall or trim for additional ventilation.
If I go ducted, then I can run ducts to the forward bedroom of the trailer as well as one to the rear bunkbed space, which should improve the camping experience in severe heat quite a bit. The best plan I've developed is a drop ceiling: 3.5" for the rectangular duct register, then 3.5" for 2x4 joists going across the trailer, then another 1" for strapping running fore-and-aft. That is ~8 vertical inches tied up with a drop ceiling. I can put some foam insulation in there but its a lot of space that could be used for cabinets and such up high. Installing the drop ceiling will be a bit of a PITA.
The overall trailer is 88" interior height, so I do have sufficient space for a comfortable living area even with the drop ceiling.
One final factor -- I have a smaller AC unit (powersaver model) that can be run on a 2K generator. So ducting may make the most of a limited AC source, and a few more inches of insulation in the ceiling is never bad.
Based on reading what people in "normal" camper trailers say, ducted is 100% the way to go with a trailer this size. Giving up 9" of interior vertical space that could be used for wall cabinets, shelves, bunk beds, etc seems like a lot though.
Thoughts?