Help

How do I need to vent a 9'6" x 9'6"x 8' growroom has a veg closet wondering what size fan and scrubber?? Thanks will be coolIng 2 1k hids on mover

I would use an 8" inline fan and an 8" x 39" carbon filter. Most 8" inlines are 700cfm or so. However, this is with zero resistance. Count on around 500+ cfm through the filter, which will cycle your entire room in under 2 minutes.

https://www.rollitup.org/indoor-growing/407048-20-000-watt-medical-grow.html

This being said a say 900 sumn cfm fan would be big enough to run a carbon filter and 2 1k lights?? I'm bumping a 12.5btu window unit

Here's a pic what kinda air do I need to be bringing in from outside?

Odor and heat I don't want to suck all my cool air out but undone want to loose my negative pressure how do I go about this being outside where outside temps get hot

Ambient outside temps over 70? Then your looking at another form of cooling...air conditioning. Even pulling fresh air from outside, then through the lights, then exhausted outside will probally keep the lights cool enough if you can get the air moving fast enough. Although, if you can effectively get rid of the heat generated by the lights you are left with the ambient temp. to deal with.

How cold does it get there? You may want to add a speed control for the exhaust fan in the winter time. They run about $25.00. Either that, or a thermostat for the fan. I like the C.A.P. line of controllers.