Ceramic glass doors a masonry fireplace and do not care about any heat coming into your room then it is ok to burn a fire with your glass doors closed.
Gas fireplace doors open or closed for heat.
Large 10 class a metal chimney required hefty 1000 lbs of masonry firebox unsealed good radiant heat and open to the room no fans or accessory heat ducts.
All gas logs should be burned with the doors wide open even if a mfr tells you they are approved for closed doors.
If you close the doors the flames pull towards the glass where it can impinge and shatter the glass.
If your fireplace doors are shut oxygen cannot reach the flames.
This results in a dull blaze with little heat output.
Oxygen is a key element in healthy burning fires.
In the off chance you have.
Designed as a surface mount these track free doors sit outside the fireplace opening against a flat surface and help reduce.
99 of the time your fireplace doors should be open when you are burning a fire.
It is still an open hearth fireplace which is susceptible to aerodynamics.