Most run the 315w open, no air cooling or glass.
Vertical bulb reflectors are probably superior to most horizontal bulb units.
But, verticals are taller in size, and more expensive.
I like having the ballast separate, not internal. That way I can mount it in or out of the grow space. Easier to troubleshoot/replace.
I have 2 of these over a 4x4. Can always upgrade the reflector down the road.
Reflectors only get warm to the touch, never hot.
Regardless of light technology, heat will be produced. Gear up to manage cooling.
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