Love how well this enclosure is working out for me. I opted to make my own heating/cooling system for the box. It has a pro mini (for now, rpi later...) that controls 2x 40mm mixing fans, 1x 92mm cooling fan, case leds, spotlight led, and a 250W heater. The cooling air comes in through a louvered 120mm damper in the bottom left corner, and exits through a 120mm flapper damper. The inside is insulated with reflectix. The mixing fans are arranged for circular flow, and they are pwm controlled depending on the heating/cooling needs. The cooling fan is pid controlled, which performs great keeping temps within +/-0.1C. The hysterisis controlled (via 50A ssr) Honeywell personal heater has been modified to remove tipover protection as well as bypass the bimetal thermostat (which limited case temps to about 45C). I added a big and bright vfd display with 3 button menus to monitor and control everything.
With these mods, printing abs with the bed at 110c at 22C ambient... with heating the enclosure stabilizes at 50C about the same time when the bed finishes preheating. The heater then typically remains off the rest of the print as the hotbed heat is enough to maintain 50C... in fact at 22C ambient longer abs prints the coming fan averages about 20% to hold 50C. In the winter time (<10C ambient), the heater starts to toggle throughout the print to maintain the set temp.
I am completely satisfied with the results. My abs and nylon prints have no more major warping and very good layer adhesion despite the unpredictable environment where it resides (a non-climate controlled garage).