Btw if you are doing 4 1000w lights you better have a few hundred for an AC if not over 1000 dollars for a mini split. Don't just buy 4 lights and start growing with H/O fans, Exhausting fans ain't Gon do shit but keep you at 85° unless your in Alaska and can pull cook air in all year round, but then your dealing with potential bug infestations. You have much to learn grasshopper.
I'm not here to be a dick so let's help you out a bit.
You should not exhaust any air at all and purchase a co2 system in order to keep your air recirculating for highest co2 saturation =. Larger yielding plants by 15%-30%.
If your worried about yield look up some high yielding strains, which most will yield pretty fair if you do things right.
For each light I typically won't use more than 4 plants but many people use a method known as
sea of green where many small plants make a canopy much faster in veg with more plants.
For your setup to yield very well with the right amount of love and care, you will want the following
2 ton a/c (mini split or 20,000btu of cooling power)
Ducting to cool your lights.
but in an infinite circle not pulling air in or out
Or
Pull air from a warm room of the house by cutting a 8" hole in the wall then after cooling the four lights duct leads to the window. (Therefore there is no CO2 wasted) GETS EXPENSIVE!
mount about 8 fans around your room evenly spaced
Get 2 4x8 flood tables for your drainage/runoff
Get a water wand and pump to hand water your plants
Get a reverse osmosis system for clean water
Get ph and ppm pens
Decide on nutrients. I prefer 'SUCCESS NUTRIENTS'
Get some 1x1 cubes for seeds/cuttings
Let me know when you get this far and I'll keep you going
