![Arctic Bear HD heater Arctic Bear HD heater](https://media.baumpub.com/files/slides/locale_image/full/0032/7791_en_59d0b_22171_ground-9.jpg)
The Arctic Bear HD indirect-fired heater is designed to run 24/7, andfeatures a 100 percent stainless-steel firebox and heat exchanger. The unit’s heat output of 430,000 to 770,000 btu per hour varies with outdoor ambient air temperature, with a maximum temperature rise of 240 degrees Fahrenheit. Airflow rates vary with ambient air temperature and duct type diameter and length. The three hp backward-inclined, electric-powered centrifugal blower typically operates in the 3,300 to 4,000 cfm range, and diesel, natural gas or propane engine options are available.