Hey Green Knight
the unit draws air from outside the room and then blows it back out to cool the condenser,and draws air from in the room cools it and blows it back into the room so they're should'nt be any co2 lose from it.there is a good chance that the room is leaking air as well,its going to have to do until I build they're new home out back in the spring.Im really looking forward to building a "workshop" from the ground up designed around my current system, its gonna be sweet!
ps:glad you like the set-up bro its been a work in progress for a year now.Its staying like it is until the new rooms are built.thats when I ll get into burners,res chillers and all that cool shit