I can only tell you what works for me.

I have an outdoors shed that I use as a grow room, and temperature control was one of my major problems. Cold in winter and hot in the summer.
I found that you can get inexpensive temerature controllers to control the exhaust fans. I use one ( 4 in. ) fan that runs continous and sucks the air from the rafters and exhausts outside. I also have 2 more 4 in. fans that are on temperature controllers set at aproximately 80 deg. so they only come on when the ambiant temperature hits 80.
The temperature controllers are fairly inexpensive units that I picked up at the local hardware store for around $20.00 ( US ). They are made to control attic fans and are ideal for what I use them for. They are also adjustable from around 60 deg to over 100 deg.
I try to use the heat generated by my lamps as suplimental heat in the grow room, ( I use a 1500 watt, thermostatically controlled ceramic heater to maintain temps ) The 2 fans that are temp controlled are hooked up to my lamps so as to only come on when it gets too warm. Note my 400 watt lamps are not enclosed, just fitted with reflectors, but the flexible ducting is hooked up too them so as too draw off the heat and exhasted outdoors.


As far as your idea of re-circulating your air, BAD IDEA!!!! Here is why.
If you are taking the air from inside your grow room, moving it too your living quarters, and putting it back into your grow room you will have problems. Your humidity will be exteme or next too imposible too control. You could inadvertantly introduce fungas spores and other nasties in this manner ( do you have dogs or cats?). And your whole house will smell like a marijuana garden.

Good luck in your grow

( Just my two cents worth, take it or leave it )
Randm999 Reviewed by Randm999 on . Inside Exhaust? What am I not getting.. Hey guys, I'm very hesitant to take the final step and purchasing all my equipment until I'm sure of the design for my growroom. I'm from Europe so I won't have the specific words for construction stuff or what have you (Also itâ??s pretty cold over here). So here goes nothing... http://img402.imageshack.us/img402/3194/room2.png http://img94.imageshack.us/img94/5781/roomd.png As you can see it's going to be pretty cramped in there, and the proportions aren't right because I don't have Rating: 5