It looks like the fan on the bottom of the drop in unit will keep air circulating around in side of the area and should help with any condensation issues. Though you might want to add a vent soffit somewhere to allow any heat build up to escape. Though there is not a lot of heat with the stand alone units since they don't need a fan.On the topic of adding insulation- I ended up buying the drop-in unit with the attached compressor (it is attached to the bottom of the box). I'll have lots of dead space around the unit when I install it. Any ideas on how to improve the insulation (without "insulating" the compressor and retaining the heat)? Also, wouldn't adding foam around it create an environment for condensation and risk damaging the unit from corrosion?