Trailer venting in different ways

[wopachop]

The idea behind this first one is inspired by an insulated coffee cup. Or dual pane window. What if you could somehow cool the attic space above the trailer on hot days? Just like an attic vent does in your house. Or the way a dual pane window uses a buffer of air to keep heat from transferring as much. 

Trick here is taking advantage of the crappy build quality you find in trailers. My roof vents do not seal out the attic space. There is a pretty big gap where the roof vent sandwiches together during installation. 

This trailer has 3 roof vents. The center vent has a powerful MaxxAir fan blowing outward. If you plug up that center vent intake, it ends up drawing air from the attic space. Since the roof vents are not sealed very good, this also pulls air from the trailer living space. 

Ive tested this a couple times. It works OK. I can tell the trailer is definitely cooler. Hoped for better. This trailer is not insulated very good from the factory. The MaxxAir fan has a built in thermostat. Im thinking about leaving it all hooked up like this while the trailer will be stored for a couple weeks. Looking to be a super hot weekend coming up. For people with solar who store their trailer this could be a possible option to keep temps down. 

 

[wopachop]

The rear vent with the square cut out of the foam might be confusing. The square used to fit a 12v fan for a roof vent that didnt have a build in fan like the bathroom. Normally i have a fluffy reflective pillow up there. The square shape was a good size to suck up a paper towel, trying to show the amount of airflow. Takes a good amount to hold up a shop towel.

I got to think the system would flow better if you left the vents clear. But it also lets in outside heat. Found a nice little middle ground there with a pillow hanging off sideways. Or the 1" thick rigid foam with a hole cut in it. Reflective side facing upward of course. (thicker would be better, i have 1" on my windows. Just the right size to allow the blinds to close)

I wish i could blow air from the vent into the attic space using a fan. But im being super careful about the flow of dust. I dont want any insulation fibers from the attic coming inside the trailer. The cutouts in the ceiling for lights and speakers and AC ducts are never sealed good. So blowing air into the attic just wont work. The way its setup now, with the MaxxAir fan on full blast and the roof vents somewhat restrictive, im guessing its a negative pressure up there. Which is perfect. Suck all that nasty stuff out. I have a dead mouse up there from a couple years ago. I smelled it the other day when i first turned on the AC. Drives me nuts smelling it. This sort of evacuates air that might sit stagnant for years.