open doors on a direct-vent gas fireplace?
I seem to see brochures that let you specify working glass doors for direct-vent gas fireplaces. I was surprised because I'd read elsewhere these are closed systems. One brochure even seems to advertise an optional pair of bi-fold doors (total of 4 hinges).
Anybody have experience opening the doors on a direct-vent gas unit? Any comments on flame or ember appearance quality with doors open?
Anybody have knowledge or reasoned opinion, if a direct-vent is burning steadily, would the open doors release more monoxide into the environment or less?