Do the cool tube reflectors require venting or can they be used without? Wondering if they get too hot inside being enclosed with glass.
I just wondered that since it's a somewhat large grow room, I wasn't sure if I needed a cool tube as opposed to a non-tube reflector, but figured I would get the cool tube just in case the room got too hot, and if it was an option not to vent it at times if I decided to utilize the heat for the room and just blow a fan below the lamp rather than venting. Winter's coming and don't want to waste the heat.
Gotcha. Go for the cool tube then. Any cool tube from a reputable source will be made with glass that's able to withstand the heat from HID lighting.
So do cool tubes come with a fan? It wasn't in the product description that I'm looking at so I'm trying to find out...
I think most cool tubes are made of Pyrex... which is pretty tough stuff. I don't know exactly how much heat it can handle but its a lot and likely more than an HID will produce. It seems from a little bit of internet research that Pyrex has been called a "weapon of glass destruction" because they can explode in some circ's... but I think this is primarily when you move quickly from hot to cold or cold to hot OR if water gets sprayed onto really hot pyrex glass. Avoid these things and no worries!
^ you're right VI, exploding/cracking pyrex is caused by drastic temperature changes (just like moving a pyrex pie pan from the freezer directly to a hot oven would cause it to break).