" My wife and I purchased our Acucraft Z-Max 5 years ago. We built our 3500 sq.ft. House ourselves. We installed R-33 in the roof system and R-19 in the walls with 1/2 log siding. We intended for the fireplace to be a supplemental heat source. After our first few fires using the blowers the Max heated our entire house, even with the 26' ceilings! Not only is the fireplace a great heat source,it's also very efficient. We usually have 20 to 30 fires a month with good seasoned hardwood that burn all night. I clean the interior after each burn. There is less than a 2 gal. Bucket full of ashes! Great engineering! "