How much ventilation do I need in the winter time, in an outside building.

Will I still need a lot of ventilation even if I'm growing in an outdoor building while its winter time? Or will an oscillating fan and an exhaust be enough? The main reason for ventilation is to get rid of heat correct, but I want to grow with LED lights which don't generate that much, plus its winter so it could get pretty chilly if I'm bringing in air from outside.

No one has their 2 cents to pitch?

Chances are if your using l.e.d.s your going to need to add heat, not exhaust it. Especially if your winter time temps drop below freezing. My room is in a garage with no insulation making temperatures similar to outside temps. I built my room out of polystyrene insulation and sealed it up as much as possible. Just a few tiny cracks. I run a 400w mh for veg and that room can stay 30+ degrees warmer than outside air. So if its 50 f outside, my room is roughly 80 f. When winter hits hard it'll be around 15-35 f outside so I myself might have to add heat (or more insulation) to make sure temps don't drop too low.

My advice would be to build a room just large enough to accomadate your plants at full maturity. Then insulate the hell out of it. For fresh air exchange I would look into DIY co2 or buy a co2 system if money is no issue. That way your not pulling in freezing air.

Yea if you're using LEDs you shouldn't even be thinking about exhausting heat. 1/2 the reason for buying an LED is the low heat generation, other 1/2 is the efficiency. If your building has good enough insulation, you just need to circulate the air inside and you'll be fine. Not sure how large your building is, but a space heater or something similar might generate enough heat to get you at the right temps. Like I said, don't know how big the building is, so I can't figure out exactly what you need

There are so many variables it's impossible to answer your question. Like how large is the building? are you growing in a tent or room within the building? is it insulated ? Do you live in Fairbanks Alaska or Phoenix ? Can you modify the building if you need to cut vent holes or rewire or something?

There are always a few different ways to accomplish an objective, and yours is to provide and manage fresh air, at a temp & humidity that lets you keep your grow area within the min/max range that you want your plants to live in.

Maybe some pics and more info and you'd get some better suggestions, but personally I don't know enough specifics about what you have to work with to offer suggestions.

Thanks for the responses. the building is 6 feet high from floor to ceiling, 9 feet long and 7 feet wide. I dont have a grow tent or anything i wanna grow right in the building there. Its fairly well insulated, I live in southern manitoba

How is it heated?

There are always a few different ways to accomplish an objective, and yours is to provide and manage fresh air, at a temp & humidity that lets you keep your grow area within the min/max range that you want your plants to live in.