No heat escapes bc the fan runs 24/7, pulling hot air in the tube from the tent, thru the vents, from the outside. At first I just used the passive vents on the tent. But when I switch to 400w in the last 5 weeks of flower, the vents couldn't keep up. I stuck a 4" aluminum inline duct booster fan into one of 4" tent ports and that helped airflow alot. I can promise you one thing about a tent that size, you can definitely turn a few zips of nice flowers, but you're gonna work your ass off dealing with moving that heat out. Radiant heat is the problem. Hell, I was pulling air with a 170cfm fan thru only an 18cf tent and couldn't keep it cool. That's changing the air out 8+ times a minute. The problem is that the area is so small, the energy from the bulb heats everything inside including the walls themselves up. The only solution I've ever found is cooler intake air. If I'm running 60 deg f air into the tent and the light is raising the Temps by 20 degs, that keeps it about a tolerant 80 f.
Sorry, just wanted to share that while we were talking about venting that thing. Using a bigger fan doesn't help when it's already changing it out 8 x a minute, lol. It's gotta be cooler to start with.
