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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.
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 :)
you'll need at least a 243cfm to keep that size area at a moderate temp using a 400wt lamp,and a passive filtered vent opening(about 12x12 on lower opposite wall side of the fan)so that there is free air exchange in between the room and lamp....bonbon
bonbon,
Thanks for the info. Would the same apply if the lamp is air-cooled? Also could I exhaust both the lamp and room with one 248 cfm inline fan?
Would a 148 cfm exhaust fan be sufficent if I used a 250/270W HPS?
Do you mean to use a air cooled reflector to exhaust lamp heat and air exchange?you could,but your open reflector will attract dust and airborne particals as well,some of which will be trapped in the foilage and coat the bulb,that will hinder some of the light output and the plants ability to absorb fresh air,I would use seperate fans,one for the hood with the lens on(the lens protects the bulb from dust and contains the heat)the other for air exchange(a 148cfm for each will work fine)