.."IMHO" definitely need thermostatically controlled extraction at least, and probably same on the window unit for initiation.
I'd have to go dig up specific numbers, but I believe somewhere in the 90-95 F is 'optimal' with co2 induction.
If your using a window a/c it's not a sealed room. If you are in a neighbor hood with other homes with in 30' or so they will smell you. Other wise it's still a good ideah as long as you can keep your temps under 86 deg. and humidity under 65%. Co2 only gives you benefits if your other values are in optimal conditions. Temp, rh%, and good canopy air circulation. Good luck.
most window units dont exchange the air in the room, a small amount of air may leak threw though, but they pull the air from the room in, cool it, and blow it back into the room.
:yeahthat: There are 2 sections in the unit that are sealed from each other, the evaporator and the condenser, the fan is double shafted with a fan blade on each end.
As long as the vent button is not pushed its sealed good enough.