2x3x4 Grow room heat question

I have a grow box 2ft x 3Ft and 4Ft tall My ventilation is 1 Box Fan and a window fan that's actually to medium size fans in one set up.

In the bottem have three 1 Inch holes drilled threw my building to the outside to pull in fresh air using the box fan and a 3ft long 2inch wide slit in the top to vent out Hot air using the window fans.

I can also add another box fan that i happen to have available.

I would like to use 2x 150Watt HPS Lights but am worried about over heating my plants or worse BURNING MY HOUSE DOWN?

Was just wondering if any body with experience had any ideal's?? Could tell me if this is feasible etc?
Thank you
DDC

chamberlaindavidd said:

I have a grow box 2ft x 3Ft and 4Ft tall

Click to expand...

Slightly larger, I use CFLs exclusively as I worry about the risk of fire. maybe paranoid.
I use a 6000 BTU AC unit ( the small kind, for about $100 ) , but I'm in a garage. Thats 460W CFLs, puts out a bit of heat. I was able to keep the box at a reasonable temperature with only a 160 CFM fan, the temperature about +10F diff between inside and outside the box. > 86F was a killer.
Great results in veg, flower, not so much.
I use HPS but only in a larger area with a lot of airflow. With that space you have, you may be better off with 1x400W, but def get a cooltube and a good fan.

3'x4'x'4 :

1) Center bulbs / Vertical
2) Looking w/open door