I would use a carbon filter and maybe an ozone generator. I have kind of the same setup. My room is isolated from everything, no incoming or outgoing ducts, windows, anything. In the winter i use the heat from the lights to warm the room, and space heater at night to keep the temp steady. I use a combo carbon/ozone filter and just filter the air right back into the room for recirculation. If it gets to hot in the summer, i have a small standalone air conditioner, which is also a dehumidifier. I found everything i needed at home depot.

The air conditioner was kinda pricey. That DID have to have an exit vent because of the hot air created to make cold. Not much I could do about that.