Hi,
same size tent as my old one, an heat was always a problem unless I left the tent door half unzipped. I can recommend having a fan inside the tent, instead of blowing air from outside in, use your extractor to draw the hot air out otherwise it will just hinder and cause high humidity, especially after watering. Once you have the fan in there and your extractor sucking the hot air out of the tent, whichever room your tent is in, leave that window open.. You'll be surprised how much it helps maintain a steady temperature as the outside of the tent being cool will keep the inside of the tent a good temp. Otherwise the whole room just cooks, had that problem and I really didn't enjoy it! Let me know how it goes and hope it helps you out.