1000 watt how close?

How close if using an exhausted ac hood could I put a 1000 watt light? 2 feet 1 and a half, in Jorge cervantes's book it says 24 inches but I was wondering if I could get it closer.

anywhere from 12 to 24 inches the closer the better. but that is in my case every room is diff so good luck with everything

Position your hand at canopy level with the light at full power, lower the light until you can feel the heat on your hand if it is uncomfortable for your hand than it will also be for your plants. In other words if it hurts you it will hurt your plants.