Anyone use outside air intake for grow room?

Have an old unused vent duct that I'm planning to use with an adjustable fan to bring cool air into the room.
Anyone do this?
Any problems with it?

I do it, large 12 inch intakes with 12 inch vortex blowers. I use dust shrooms to filter the intake.

I do too. When it gets over 84 the fan kicks on and pushes cool, outside air in until it drops to 76.
I use a dust shroom too but only in the summer. I don't like how it kills air flow.

I don't notice the dust shroom killing flow but I do have large blowers and all my ducting is galvanized snap seam. I can see it when they are dirty.

All my air comes from the outside, I use 2 older, "McLean Midwest 1000CFM AC/DC 1600RPM Heat/AC/Humidity Controllers" they are squirrel cage, centrifugal blowers that have blue & white merv8 filters on them. As there is nothing like the constant flow of fresh clean air going into my grow areas!

I have a small stealth grow on the go. I have a 4" fan pulling air in from outside into the cupboard and another 4' fan pulling the air out of the cupboard. In front of the inlet fan, I have a small computer cooling radiator with water chilled by an aquarium chiller pumped through it to knock the outside air temp down. Also run a small humidifier and a dehumidifier to control humidity. Both the humidity and temp systems are automated.

I run outside air24/7,passive.My air pump sits in front of it, keeps it cool.

I just installed this it seems to dots job with my intake fans. I can change settings via wifi.

I mostly use the air from my house but I do have electronic dampers connected to a thermostat and if it gets to hot in the room it opens and blends with house air. I also have a canister filter hooked to my return on my HVAC with dampers so at night when it's cold out I use the heat from my 5 1000watt hps to warm my house plus it keeps my energy bill from fluctuating in the colder months since I only grow when it's cold outside

I use this unit;

https://smile.amazon.com/gp/product/B00V4TJR00