XTD 1.5 is designed to be inserted inside of a masonry fireplace. This EPA high efficiency technology will dramatically the heat output of your fireplace,while using a fraction of the wood of a conventional fireplace.. Homeowners will enjoy the convenience of “Single Lever” air control and this insert includes ablower fan. This medium size insert will accept a large 20″ Log and will heat up to a 1,600/sq.ft home.(60,000 BTU’s) 1.9 cu ft. fireplace. Minimium fireplace dimensions necassary to install this this wood stove is 29″ wide,21″ High x 14″ Deep