Help with ventilation for veg room

I have a 3X5X6 room for my clones and veg. I need some heat in the room so I don't want to exhaust since it will clear the heat out of the room So I have a 4in. passive intake, 3 1/2in passive exhaust and a 7 inch. fan circulating the room Lights are T5's. Am I going to get enough circulation with this set-up? I do have a little exhaust fan hooked up but don't want to use it.
How do you time your exhaust? If I did exhaust the room (90cf) how should I time the exhaust and what timer should I use?
I would rather be able to use this passive intake and exhaust if possible. Thanks ahead of time. I just put my germinated seeds in tonight.

MG, 3x5x6? Is this a box or a tent or a closet or something like that? I run my exhaust fan 24/7, it's good not only to move the air in the room, your 7" fan, but to get fresh air into the room as well. A passive intake and exhaust system isn't really going to do very much, the air won't move on it's own. Do you have pix and greater detail?

ow.douglas said:

MG, 3x5x6? Is this a box or a tent or a closet or something like that? I run my exhaust fan 24/7, it's good not only to move the air in the room, your 7" fan, but to get fresh air into the room as well. A passive intake and exhaust system isn't really going to do very much, the air won't move on it's own. Do you have pix and greater detail?

Click to expand...

OWD It is a built room. I decided to run the exhaust 6 min/hr to clear the room. I am worried that if I run it all the time, the heat won't stay in. I did that for one day and the temps ranged from 70 to 78 degrees. The little seedlings seem to be recovering from the transplant. 4 are perky and reaching for the light. One is a little wilty but better than last night. The other is too small to tell but seems perky. I think I will try this for awhile. Plus They don't use much oxygen at this stage, right? Anyway, no pics at the moment. I'm new to all this and trying to get it up and running first.

try and insulate your grow space then try your exhaust fan

Tiny plants only use tiny amounts of air, and amongst other things CO2 is important to replenish - as that is what the plant uses in photosynthesis. I think you can add CO2 to the room, to offset ventilation, to some degree.
At least I do that, for same reasons - conserve heat. Seems to work, I just use sugar yeast in a 5 gallon bucket - in the closet. Kind of messy, but it does produce CO2.
Good luck.

I wish I had to conserve heat, that is a nice problem to have. Pics would help me help you.