A small grow tent has worked just fine for me except the hottest time of the year, even then it's only 64°-66°F inside. Corner of a Basement with two adjoining exterior walls contributes and maintains cool temperatures, concrete floor also contributes to these cool 60°f temps, 60% humidity also contributes to lower temperature. My 3'x3' tent with a automated humidifier set to 60% and an inline fan creating slight negative air has maintained 60°F & 60% humidity +- 2% easily for 8-10 months of the year, even then in the hottest months of the year I use a dehumidifier for the whole basement to maintain 60% and the temp is usually under 65°f. I really don't see any advantage with using a cannitrol in my situation. The cellar is a proven concept that is ancient, just gotta keep slight airflow and humidity in check. I'm sure a cannitrol is nice, but to me it's overrated and unessesary. Just reminds me of ice fishing electronics nowdays, people think that they need a $2,000+ pan view fish finder to locate schools of fish under the ice. Now at least half the people out there have this glorified technology.