Active intake, passive exhaust or opposite

Putting together a grow area in basement from a pre-existing block room, have environmental questions about hvac. I will have fresh air flow to give close to one turnover per minute cfm. Fresh air intake near floor, exhaust near ceiling. Also fan(s) in room. Have some heating capability and a dehumidifier. Since I am bringing in fresh air I will be limited greatly to outside temp and humidity, and hope to be ready to start veg in April. Besides the topic question (which I think will be determined by installation ease), is there any expectation that I can alter temp or humidity given the rate of room air turnover, enough to make a difference or will I be at the mercy of outside conditions?image

I think @Countryboyjvd1971 can help you whit that. :wink::+1:
Personally I will get the intake from inside the house…


I have always done it the opposite, mainly because of use of carbon filter.


Youd be better off doing passive intake
Have have exhaust pulling air out of space
If i can assist you more feel free to tag me
Im a commercial Hvac mechanic :+1:
Happy growing


The only ventilation in my basement is from man and garage doors. Not much turnover at all. I did consider your suggestion because the temp and humidity is more stable.

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Because of my location, odor is not a prob.

I still agree with @Countryboyjvd1971, that you’ll be better of running active exhaust and passive intake. Even without the filter, let it draw what it needs passively while having greater control over what you get rid of.


I’ve got mine that way, have variable fan pulling air through tent to top. Opened small door at bottom, outside air is cooled and dehumidifier, pulled up and across plants. I have a temp and humidity meter at exhaust side as well. My temps and humidity ran high earlier and I was able to get better control this way


How much activated carbon to use for a 160 cu ft space? Thinking about a DIY filter, on the cheap.

Carbon filters are fairly cheap
This would be good for your space @roaddog