winter exhausting question...

[jonnieb]

New to forum. switching from CFLs to a 600W HSL system. Built an insulated 4x7x6 grow room inside of an unheated, uninsulated shed. Live in Northern MN (frequently below 0 daytime high, etc.). Concerned that having an intake duct to light as well as an exhausted duct (with fan) may cause too cold of temperatures when light is off (currently in 12/12 mode). I currently have a small heater which has been adequate with the CFLS for keeping room comfortable. Don't wish to babysit and have to mess around every night with unhooking ducts, insulating holes, etc. So far the light keeps the room about 70, but our daytime high has been below zero. I know once it warms a bit, the room will be way too hot and will need to have an intake/exhaust system. I have had some just decent grows the past few years without venting the room, but I seek more than decent size buds, thus the upgrade...hope this makes sense. Any advice is appreciated...

[Potted]

I would use a flapper ( that’s what I call it ) at the end of the exhaust to prevent cold air from backing in.
It opens when fan is on and closes when fan goes off if that’s what u mean.
home Depot

[Flockshot]

I have a high level of confidence that you do not want to draw any of that north Minnesota, 0 degree air into the box.

[UrbZ]

I live in Michigan and I was dealing with the same thing. As soon as it got around 50-55° my windows got closed as I was already battling cold temp issues. I wouldn't dare try now.

[jonnieb]

Thanks for the advice. Made some Home Depot purchases today. Think I'll try just venting out from the light without an inline duct fan going and see what that does. Room was 82 when I got home. With weather climbing to near freezing, need to exhaust the heat.as I'm sure it will climb to 90 or better. Not conducive to the flowering stage my plants are in. I will be using a "flapper" once I get the exhaust fan going. Gonna also hook up a thermostatically controlled outlet for the fan. Always an adventure but we wouldn't have life any other way, would we? My girls love their new light! Onward to big buds!