Quote Originally Posted by senorx12562
I'd be wary of putting a fan downstream of your reflector though, as drawing hot air through the fan motor and bearings won't do them any favors when it comes to longevity.
If properly set up, there is no heat issue at all. I think that bit of popular info has its roots in folks who didn't really understand their airflow requirements. With the passage of time it seems as though it has become accepted as a fact.

The air temp rise from a single 1000HPS with good airflow will be on the order of about 4 degrees F. I've set up banks of lights in series of 6 with a single 8" fan, outlet temps were under 100F with an inlet temp of 70-75F. Any diminished longevity is negligible, unless temps get a good bit higher.

The bulb itself is in the neighborhood of 200F, so with inadequate flow things *will* go south quickly! :detective1:

Not jumping on you, Senorx! Just thought I'd throw this out there. I've seen it posted many times and it's really not a problem. HVAC/R for a couple decades taught me a thing or two.