Can't vent exhaust fan outside, is this a problem?

I,m in. 2x2x by like 5'4 (60x60x160) and I have carbon filter exhausting at the top, using about 1m ducting venting out of top hole to the left side, and an active intake on the bottom porthole sucking in fresh air on the right, get a bugnet for your intake fan so you dont suck any pests into your tent, the active intake helps if you are venting into your room, make sure active intake isnt as strong or stronger than exhaust. Depends on your light but I use a mars hydro ts600 and my temps are 20oC lights off to 26 lights on, I keep the window open to the room for fresh air exchange but the tent is stashed out of the way and can't be seen through the window and there's no light leaks. Hope that helps

I have my plant growing just fine, with this EXACT setup. See my current diary for example. My recommendation is to still hook up your excess ducting to the exhaust and run it into a closet, it does have a dramatic effect on the temperature because it allows the air time to cool before exiting, you don't want all that heat coming right back into the tent.

no carbon filter will keep the smell down. You will just have to watch your temperature. if you can have an intake vent for fresh air that will help alot.