GrowCNanswered grow question 4y ago I use the AC Infinity Cloudline fans with digital controls. These allow you to program the temperature and humidity you want inside the tent. The controller turns the fan on and off as needed to maintain the conditions you want. And, they are extremely quiet. In North America they are easy to find. In Europe I believe they are resold by Mars Hydro though they don't use the AC Infinity name.