deff wanna keep your air flow up so as sugested above add a fan, and if you already are exhausting air from the top thats a good thing, and alot of people will tell you you humidity is way to high and you will get powdery mildew by doing so, but realisticly high humidity is not a serious problem as long as it doesnt majorly fluctuate up or down, its the huge swings that cause issuse. but again watch closely with %'s runnning so high and if PM shows up its best to start trying to stop and control it early.