400w Cool Tube Without Fan

Is there anything wrong with using the cool tube without inline fans for a few days? Will the glass break from the heat buildup?

i would think you will be ok as long as it does not cool down to fast. ie cold air hitting it after it has turned off.

Actually that would just make the light put out less lumens for a while. The hotter they run, the less efficient they are. Damage can be permanent but a couple days is not a big deal.