can I?

can i use a Dominator XXXL 6" hood Grow light 1100 hps without the glass door???

Isn't it there to help maintain airflow?

Sure you can, why couldn't you?
You wont be able to air cool it but it wont hurt to run it open, plus the glass eats up lumens.

Sure you can run them without the glass, but if you have ducting it's going to suck out the air. And if you don't have ductwork you can still do it but your temps are going to be higher, could burn the plants so keep a fan on them. Also will lower the lifespan of the bulb in the long run from running hot.