Originally Posted by Fman

I understand what you want. I hope this pic. helps. The intake air that is coming in from under the house is 76*. There is a 200 mh cfm 25' away pushing air to my room. The exhaust fan is a 350cfm drawing the hot air out the roof of my room. Where are you going to get your fresh air from? If you are going to get your intake from the same place your exhausting into, you might find that to be a problem. As you can see my 250mh is 90* and thats with cooler air blowing over it . I hope this helps. Also I included pics of my air ducts . Both the room and light are cooled from the same plenum, thats behind the wall on the floor. I know a mh is not a hps, but I dont think there is much difference in heat. Watts is watts. And that is where the heat come from (I think).

watts is the capacity to do work...in a light bulb the watts do two things...give off light and heat....in efficient bulbs the ratio of light to heat is high...in less efficient bulbs the ratio of light to heat is low...so watt is watts but large hid watts are less heat per watt and more light per watt than most other commercially available lighting

Attachment 12312

Attachment 12313

Attachment 12314

Attachment 12315

Attachment 12316

Attachment 12317

Attachment 12318

Attachment 12319