[rich2002z]

my room is 30X13. how big the blower I need to get the hot air out? I am currently running a 14' 1800cfm blower with 10 nanolux 1000W DE.

[Phaeton]

A lot depends on incoming air temperatures and whether or not the sun is shining on one of the walls.
My 12' x 12' budroom (5 KW) has has two intake fans (2500 CFM each), high and low in a corner, creating positive pressure with filtered air.
Temperature is controlled by adjusting the exhaust vent.

On a hot summer day with the fans on full and the vents wide open the room will hold three degrees over ambient. Good until the outside temps hit 85 F. Six weeks every summer is spent on night schedule.

[corky1968]

Normally, you want air movement great enough so as to exchange all the air within 2 or 3 minutes or less.

So if you have a 300 cubic foot grow room. You would want an air exchange fan that has a minimum output of 100CFM.

I would say you need another 1800cfm blower.

[Phaeton]

My room is 12 x 12 x 8 = 1152 cubic feet and the fan ratings total 5000 CFM.
The formula I use is enough CFM to change the air at least twice a minute in theory. It works out to much less in the real world.
Looking around at many different gardens and it seems there are no hard and fast rules.
A hot day in the summer and the air is being theoretically changed four times per minute, and still has a hard time holding three degrees over ambient.
In the winter the air exchange goes down to once every few minutes as the incoming air is under freezing and needs time to blend and avoid damage near the intakes. Dealing with nature means hands on decisions constantly to maintain quality.
I use what I am comfortable with. The weed we grow is quite versatile, it will grow under conditions that many plants would not.

The house itself has an 8,000 CFM exhaust and a 12,000 CFM intake fan for summer use. No AC, but this airflow keeps the inside of the house a couple degrees UNDER the outside ambient. No explanation for this, but it is a measured event.