Hello kzoorugger and welcome to the boards.

The easiest method of calulating heat from your lights is to treat them like electric heaters. 1000 watts equals 3,413 BTUs, so 4 of those suckers will add 13,652 BTUs of heat.

I'm assuming you are talking about using sealed glass reflectors, with outside air passing thru them, and then out. Good way to knock down some of the heat. But keep in mind with a sealed room you will have heat gain from the lights anyway from that radiant output, so be prepared for some form of additional cooling. BTW you will probably need to run that light cooling whenever the lights are on.

Don't worry about hurting the lights with cold air. The only thing that might happen is condensation forming on the outside of your reflectors or ducting if it is not insulated.

Very ambitious starting with this size grow but if you have experience growing other things, well you might pull it off.

Good luck
OM