I bit the bullet today and bought another chest freezer to use as a ferm chamber. The bin of water and aquarium heater/ frozen water bottles work great but it's a bit of the pain in the ass and on days like to today I can't get them below about 75 degrees without some help from refrigeration. I'll be using a freezer that can hold two fermenters and am looking at options to add a heater for when the freezer works too good and things get a little chilly. I've seen the ones that wrap around fermenters but with one temp controller I'd prefer something that applies a more general heat so both carboys are held at a similar temp.