Whoa! you need to have at least 160-170 cfm for that much space. You are not pulling in air fast enough! Temp on outside of tent should be very much like temp inside tent.
SAP420 Reviewed by SAP420 on . Help! Heat Prob I have a 3' x3'x4' flower tent started 2 days ago. The temp inside is 90 intake air is 85-88 and exaust air is up to 101.3. I have a 65 CFM exaust dual squirel fan unknown cfm for intake and a 400 MH. Rating: 5