i have about the same 32 inches x 45 inches x78n inches
3 and 4 inch insulation 11000 w 23 min to 400 from 65 degree start.
a little long to warm up probably due to the 16 gage walls .
for reg size parts it s ok but when doing heavy stuff like steel frames with large plate steel on them i find it a bit slow to get those part to temp