Building a hat for a Window Air Conditioner

Discussion in 'Growing Marijuana Indoors' started by SordidSole, May 18, 2010.

  1. I'm setting up a new grow room where space is abundant, but there's no inconspicuous place to put my 12,000 BTU window AC unit. I also don't have the $1200 needed for a decent single zone split AC unit, or even $500 for a decent dual hose portable AC unit due to moving costs.

    I noticed there are vents on the top and sides that draw air in for the fan to blow it over the radiator and out the back.

    What do you guys think about building a box to go over this with 2 sealed compartments? Each compartment would lead to a 6" duct. The compartment over the intake vents would draw air in from outside and have an inline booster fan to help out. The other would exhaust air back out with another inline booster fan.

    The unit, along with its new hat, would then just sit on a table inside the room, essentially becoming an ugly, dual hose, non-portable AC unit.

    What do you guys think? Am I nuts? I know it's not ideal, but it should work for a couple rounds until I can get the split AC, yeah? :eek:
  2. I made something exactly like this today. My grow tent was getting too hot with my 400hps so I went and got a portable a/c..vented out through my window and its like 2 feet from the tent. I connected a 4" duct with a ~70cfm fan on each side of the duct..(one intake and one shooting out). All I used for the "hat" was cardboard and packing tape. Basically just got cardboard...cut out a circle in the middle for the duct and made a somewhat box looking thing covering the entire a/c vents..with the duct right in the middle about 1-2inches from the vent. Taped it all it pretty air tight and turned on both fans. Slipped in the other side of the duct on the bottom of my tent and got the temps perfect...

    only con on this is that I don't want it on 24/7 so I'm building something else with just a box fan for the night time..even though I can set my a/c to just fan but I figured the box fan will consume less than that
  3. #3 aktrees, May 18, 2010
    Last edited by a moderator: May 18, 2010
    yes this will work, i have attached a drawing of how it should be done. It is important to run the duct from the side of the box with the coil in it and not the end, it can reduce a/c efficiency if you run it from the end, by reducing the effective coil surface area. If you use good foam weatherstripping to seal your box from air in the room, and in between the two chambers you wont need a booster fan, with a six inch duct, as long as your not running very far. Also for reference the slots on the top and sides is the discharge, the fan sucks air through the coil. Once you get out the window you want to put an elbow outside facing down to the ground on the side with the blue box, and just let the other one blow straight out.

    Attached Files:

  4. It will need to run roughly 20 ft, so I will still need the booster fan for optimal performance.

    The red box is the cool air intake and blue one is hot air exhaust, right?

    Thanks for your input!
  5. Its the other way around. The blue box is the air inlet, and the red box is the hot exaust. The fan doesnt push air through the coil, it sucks through.

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