Drafty direct vent gas fireplace - is there a flue or something to close?

Have a direct vent gas fireplace (Heat&Glo SL-750-TR-D) installed in a room we are not often in, on an external wall. We don't run the gas fireplace there due to odor issues that were never resolved.

I noticed tonight while moving some stuff around in there without shoes on that it was super cold and drafty immediately in front of the fireplace. Grabbed my infrared thermometer gun and despite being mid-60ish degrees a few feet away, the carpet and tile immediately in front of the fireplace is in the 40s and it's in the 30s inside the base of the unit - the same temp as it is outside. That seems pretty crazy to have that bad of a draft.

I poked around with a flashlight and dug through the dusty manual, but can't find anything about a flue or anything like that. Is there some way to close the vents on this thing? If so, is that a bad idea?

I could look into getting some of those big black magnet strips that you can put over the vents, but if there was something obvious I'm missing, I'd prefer to do that first.

If it's a direct vent, there is nothing to close off in the flue. It draws it's combustion air in internally from outside. If it has the option of a standing pilot it helps, in winter, to keep it on to keep the flue warm for draw and quicker ignition without mini explosions at start up. This may help. Otherwise blocking the vents, if you're not using, is your only option.

I did a little more exploring, and it looks like there's a lot of open "holes" under the firebox where the knockouts are for the incoming gas line, etc. I asked Heat & Glo and they said those were supposed to be insulated and sealed, so I'll try that and see if there's some way to set the pilot to always-on vs the way the switch currently starts it as needed. Hopefully that'll help a bit.

We'd use these fireplaces if they weren't so darn stinky. Despite cleaning and burning them quite a bit, we still get a very strong chemical smell whenever they are used, and so hardly ever have them turned on.

You probably either have a too rich mixture, gas is not fully burning leading to the smell when on, or you have the wrong “logs” in the fire place. Decritive only type and not high temp rated type.

I always turned off the gas line and stuffed rubber-foam in the flue in the winter time.
Never used it since it was an inefficient source of heat, and it just filled with bugs and was drafty when turned off.

Sealing up the firebox should help, but there is still very little real insulating material between you and the outside world with a direct vent fireplace.