For $30 I'll get the active intake regardless of heat. Couldn't hurt to keep things on the cooler side. Where would I install it? Does this fan vent out air or just circulate and cool the area above the canopy?

Also, I was thinking about installing two 8x8 darkroom louvers at the bottom of the veg chamber for the ventilation. Should I add a fan in the veg area as well or allow the blower from the flower cab to create a draft running upward from the vents in the veg cab.