Seriously. When I installed the Summit in April we had some nights in the 20's, and the Summit kept up with that nicely but until the other day, really hadn't tried it out with below freezing highs and overnight lows in the low 20's and windy. And I wasn't as pleased, interior temps began going under 70 into the 60's. Have gotten so used to the pattern of getting the stove up to temp and then cutting it back to low, it will go for 12-14 hours but you can reload at 6 hours, any sooner and coals start accumulating. I'm not sure what the best way is to get more heat out of it quicker so I can reload sooner, without sending too much heat up the flue.