Wouldnt a refrigereater be perfect? u cud use a broken one, just need the suction on the doors to work when fridge doors are closed the suction on the doors wud keep the smell in(heard the plants smell really strong) and wud keep it completely dark when needed during flowering. im not a grower, this is just an idea haha idk if itll make any sence lights shut be esy to install into the top of the fridge idk much about ventilation but im sure u guys cud think of sumthin haha
It's been done, but you're also going to be locking the heat in. Need to fix that ventilation. Someone here has a thread on it.
There's some DIY carbon scrubbers in the DIY section, they look pretty easy to make, it just looks like you need a good fan to pull or push the air through it