Exhaust and intake same room.

it's not optimal. I would assume with a small area that it'd recycle enough air to provide for plants A door or window open would be more than enough to maintain a normal level of CO2. Even the door to your hours being open would be enough to keep that space at a decent equillibrium of CO2 i bet. get a 6" holesaw. a cheap plastic molding and create a port somewhere inauspicious. It's worth it... do consider the light leak of an aluminum duct.. spray paint it black inside with at least 2 90-degree bends and for exhaust use only to outside since it's likely toxic fumes, lol.

Hi there! If the garage is well ventilated then I feel like you should be fine! The problem is that if you just only re circulate the exhausted air back to the tent but there will be fresh air coming all the time so no problem

Yes you should vent your exhaust to another "lung" room or outside/in an attic/or to a basement. Or have your intake come from one of these other rooms. You can choose which depending on what time of year your growing in. Do you need the extra heat from venting in your room ect. An easy way to do this is put in a Vent on the side of your garage as you would do for say a dryer unit! You can hook up a baffle to the inside of your garage to help reduce any noise that might be in your ducting so it's not to loud outside. . Hope this helps! Happy Growing!

Hi mate ;-) it is not that great if exhaust fumes get there, but at 540 m3 think it is not a problem :-)