If you blow the air outside your grow room all your doing is sucking air out of your grow space, if your dehumidifier is blowing hot air out maybe there is an issue with it. What are your settings for it how many qts is it. Also I think 60% humidity at 6 weeks into flower is too high could even lower your lights on temp just my opinion I think lowering the humidity by 5% a week starting around week 5 at 60% RH to week 10 35% RH temp 65 lights off 75 lights on, also brings out those beautiful colors.