Reznor's B gas-fired, gravity-vented unit heaters are designed for ceiling suspension with a centrifugal blower for air delivery with 80% thermal efficiency. They can be used with natural or propane gas and are specified in sizes from 25,000 to 400,000 BTUH input.

These units are approved for installation in the United States and Canada by the Canadian Standards Association (CSA). Canadian units require the selection of a totally enclosed motor.