thermo-electric win coolers. NOT the ones that use condensors to control temperature. thermoelectric ones will not cause spikes in humidity.
so, you may need to ensure the case is sealed. you'll need some sort of 2-wy humidity control, like boveda packs or similar. Youll save thousand dollars or more for the same sized unit as cannatrol and it'll do the same exact things.
Don't overpay for cannatrol. they are pirates, yarrrgh! don't give'em your hard earned money when they have a profit margin of 10,000%.