Anyone doing a 400w cab grow im nervous to order all this stuff and find out i cant keep the heat down any ideas or experience any general knowledge would be wonderful thanks!

Im planning on putting a 400 watt HPS in a 4' W x 6' T x 22'' D all white melamine Colset Maid Cabinet let me know if you have done this and what kind of intake, exhaust fan or what not that was used!

I'm working on putting a system like that together right now.

Look into mounting a cooltube on the light. I'm going to be using a 4" bake a round tube from ebay ($18 compared to the cooltubes $60+) connected to a 232 cfm inline fan from homedepot. I don't know what the optimal air movement requirements are for the situation, so I just went with the biggest I could reasonably afford. Depending on your climate, that should be enough to negate most of the heat produced.

I have simular demensions for my grow. 4' Width x 2' Depth x 8' Height. On open loop system. I'm using a 400HPS, I HAD to buy a air cooled reflector. I also HAD to buy a 177CFM vortex 4" to exhaust hot air. I have another one on a speed controller to bring in cool air from outside. My room is at about 78F-85F. Now that summer's coming, got to get an A/C, when temp outside was in 80's, my room was about 89F.