All parts of the Condar Fireplace system have been tested and approved by Underwriters Laboratories, Inc (http://www.ul.com/). The UL testing subjected the Replenum Heat Recovery Ventilator to much more severe fire loads in the Underwriters Laboratory than would ever occur under normal use. Replenum is UL Listed for your peace of mind.
Canadian Patents Pending.
United States Patents 6,742,516 B2 and 6,755,138 B2