Just ran a 30min print and noted the temperature increase of the cabinet. So the starting ambient temperature was 16 degrees, and after 28 mins of printing the internal cabinet temperature was 28 degrees. I think my original cardboard box version was getting to about 40 degrees internal. I'm going to leave the heated bed on for another 30 mins and see what it gets to. Of course cardboard is a better insulator than acrylic!