Jøtul Turbulator™ non-catalytic clean burn technology, Standard bottom heatshield, 49,756 Btu/hr. maximum output; heating capacity up to 800 sq. ft.; log length up to 16”; top or rear vent; up to 5 hr. burn time; Max. HHV efficiency of 70.0%; Particulate emissions of 2.11 g/hr; Tested on Cord Wood