I'll run 350-400 for about a day and a half, right over the cat. Starts to taper off after that. Stuffed full, with bit of an active flame, runs around 600 for a couple of hours, then tapers off to 5-550 for 16-18 hours. It'll run 600+ for a good ten hours, maybe a little more. Cold, windy days I'm loading it full every 12 or so. Lots of radiant heat thru the glass. Don't have an IR, some day maybe.