fan size

hi my dimensions cab are 120 x 120 x 200 with 400 hps what fan i should use?
350m³/h its ok?

inches. feet, meters yards, what units are you using?

and what is your summer going to be like too, if its really hot you are going to want to account for that, maybe even need an AC

my room is roughly 90 square feet, and I use a 450cfm fan because its in my room and it gets hot in the summer, I also use a 600hps


350m3/h is 206 CFM

120cm x 120cm x 200cm in summer is hot