Long time lurker, first time poster. I am building a 4x5x6 insulated grow closet in a non air conditioned garage. Temperatures in the garage range from 110F to 15F depending on the time of year. I want to mount a smaller, more efficient ~5000 btu window unit into the box itself after seeing that many people complain about the efficiency of a portable A/C inside of a box. The A/C will be mounted on the left outer wall of the box. My question is where is it best to mount the A/C? High, low, in the middle? I am concerned about the shock of the cold air from the A/C on my plants in a low installation, but also worried about the cold air hitting the HPS/MH bulbs if I have it mounted high. Does anyone have any advice on mounting positions, where would you suggest mounting the a/c within the box? Just for more info, 600 watt hps/mh fixture, open winged reflector, ballast outside of box. 6" centrifugal fan mounted outside of the box pulling air from top. Air inlets positioned 4" from bottom of the box. Once I figure this part out, I will post sketchup plans for extra scrutiny before the build.