I installed a manual Maxxair model 6200K. I have never used full speed, the thermostat control or reversed flow into van. I have a floor hole, so air flow is always out.
Do not like the Maxxair because:
1. Too much air flow at full speed for a small van. 900 CFM for a 500 cubic foot van.
2. Ugly and not stealth when open.
3. Need to close it every time I drive and open it when parked.
Procedure:
1. Removed Maxxair.
2. Retained the Maxxair roof flange.
3. Removed the metal clips for Maxxair screws to expose existing 5/16" dia. holes.
4. Bolted two 12" long 1" 80/20 series 10 extrusions to the inside of the flange with 1/4-20NC carriage bolts.
5. Made a picture frame "water deflector" from 1/8" x 1" aluminum angles bolted to outside of Maxxair roof flange using extrusion bolts.
6. Caulked top seam of angles to the Maxxair roof flange.
7. Made two fan support bars and bolted to bottom of 80/20.
8. Mounted the fan to the supports.
9. Used carriage bolts and 1/4" rod connectors nuts with spacers to make 4 lid support posts for the cover.
10. Made wood cover. If it works will replace wood cover with SS baking pan.
11. Reinstalled the inside Maxxair Garnish Ring.
Cover is 1" above the top edge of the Maxxair roof flange and extends 2" around the perimeter past the top edge of the roof flange. The angles bolted to the roof flange use 1" of the opening so there is 1" between the angles and the cover for air flow. The vent is always open. To close to limit light or insulate the opening I use a 1" thick closed cell foam plug inserted into the Garnish Ring. Top of the cover is about 3" above the roof. Hope the angles prevent water entry. We will see this winter if it works keeping water out.
Do not like the Maxxair because:
1. Too much air flow at full speed for a small van. 900 CFM for a 500 cubic foot van.
2. Ugly and not stealth when open.
3. Need to close it every time I drive and open it when parked.
Procedure:
1. Removed Maxxair.
2. Retained the Maxxair roof flange.
3. Removed the metal clips for Maxxair screws to expose existing 5/16" dia. holes.
4. Bolted two 12" long 1" 80/20 series 10 extrusions to the inside of the flange with 1/4-20NC carriage bolts.
5. Made a picture frame "water deflector" from 1/8" x 1" aluminum angles bolted to outside of Maxxair roof flange using extrusion bolts.
6. Caulked top seam of angles to the Maxxair roof flange.
7. Made two fan support bars and bolted to bottom of 80/20.
8. Mounted the fan to the supports.
9. Used carriage bolts and 1/4" rod connectors nuts with spacers to make 4 lid support posts for the cover.
10. Made wood cover. If it works will replace wood cover with SS baking pan.
11. Reinstalled the inside Maxxair Garnish Ring.
Cover is 1" above the top edge of the Maxxair roof flange and extends 2" around the perimeter past the top edge of the roof flange. The angles bolted to the roof flange use 1" of the opening so there is 1" between the angles and the cover for air flow. The vent is always open. To close to limit light or insulate the opening I use a 1" thick closed cell foam plug inserted into the Garnish Ring. Top of the cover is about 3" above the roof. Hope the angles prevent water entry. We will see this winter if it works keeping water out.