As long as you have a fan on the plants you should be ok. If memory serves me right with HPS you need the light at least three feet above the plants, I'm sure I'll be corrected if wrong.

peace
HvyFuel Reviewed by HvyFuel on . HPS Heat Dynamics For all those experienced with HPS lighting, I would like to know, is there a significant difference in heat output between a 250/270W and a 400/430W HPS light? The room is 6.5 ft. long x 7 ft. tall x 3 ft. wide (approx 137 cubic ft.) Would it be sufficient to install a 4" 148 cfm exhaust fan to control heat or would the light need to be air-cooled? Thanks for all help. Rating: 5