Mobile Home Tech: WTF is that?: Off-topic discussion forum: Grassroots Motorsports Magazine

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July 9, 2008 11:05 p.m. atlantamx3 Dork

Hey Everyone, I just recently bought my first home. Yes, its a mobile home, but its on a foundation and has good bones. We are doing the basic remodel-- recarpet, repaint, new vanities in the bathrooms, new fixtures, etc. The lady who owned it efore me really did not take care of it. Good thing though, it has a big yard, nice shade trees, and an air-conditioned workshop!

Anyway, Its a 1988 Horton model, 3 bedroom, 3-Full bathrooms.

It has HVAC vents in the floor-- but also some sort of vents in the ceiling. Thus, the WTF factor. They are not connected to anything and just vent into the ceiling. I can post some pictures if I need to, but if anyone has any idea what they are... I'd love to know.
July 9, 2008 11:48 p.m. PHeller New Reader

Is there a fan in your attic? If so, they vent hot air into the attic which is vented with an attic fan. Helps circulation.
July 10, 2008 7:02 a.m. John Brown SuperDork

Some manufacturers did that for convective heating and cooling allowing the temperatures to equalize throughout the trailer. Not everyone has the abilit to have central air, so it helps cool the entire trailer when you are using window AC units.
July 10, 2008 7:15 a.m. Jensenman SuperDork

If they are connected together, that's a return system. Some older MH's had the bottom of the doors cut about 2" short for the same reason.

Piece of advice: CoolSeal the roof, if it's metal. The more reflective it is the less heat gain inside, plus the stuff helps seal the seams.
July 10, 2008 6:20 p.m. atlantamx3 Dork

So... what would happen if I seal them off?

I ask because it feels like hot air is coming from them.

Also, isnt it just letting my AC out?

seems weird.
July 10, 2008 6:29 p.m. stuart in mn Dork

I'm not familiar with mobile homes, but there has to be a return duct or ducts for the HVAC somewhere. Make sure that's not what the ceiling vents are for before you block them off.
July 10, 2008 8:13 p.m. Jensenman SuperDork

They should be connected together if they are a return system. I wouldn't block them off, that would mean the rooms farthest from the main intake for the HVAC (usually the filter is installed there) will be too hot/cold.

If you feel hot (as opposed to warm) air from them, there may be a leak somewhere. If you are running the A/C and the air is only warm, it's doing its job.