Growing in soil with CFLs, so temps are not a problem. Colder weather here now means my top temps only get to 77F with lights on. The closet is about 3feet by 10feet (with whatever is standard ceiling height) but my grow box is only about 2x4 of that. It is open topped right now, but I have plans to enclose it completely when I add the vent fan and leave a passive air intake at the bottom and vent at the top with DIY carbon filter pad over fan intake area. Closet is almost empty so there is plenty of free air space that may be enough to just re-circulate air without needing the vent hose to outside. Finishing 8week veg in a few days and switching to flower with 2700k CFLs - expect half to be males, so I should have maybe 3 or 4 plants to finish after they sex. Plants are only 10-16 inches now, so they won't be monsters - topped most for 4 colas, so they'll be more of the bushy/stocky style than beanstalks. Have a small pan of ONA GEL in use and smell is not bad yet, and really only need to control it when family is over at Xmas next month. Plants will only be three weeks into flower then, so the smell shouldn't be at its worst. So does the 70cfm vent fan sound like it will be good enough to draw air through the carbon filter pad?