The mantel on my fireplace is unusually hot.
While direct vent gas fireplaces are designed principally for their aesthetic value, we try to get as much heat output as possible to provide added value to the homeowner. It should be noted that while we are getting a lot of heat, we are passing the ANSI and UL standards for combustible temperatures. The allowable is 117°F above room temperature for combustibles. Average room temperature is 70-75°F; therefore a 187-192°F surface temperature can be expected. On a solid surface, 150°F is very hot to the touch (to put this in perspective, water boils at 212°F and the average bath water temperature is 110°F).