Model UDZ gas-fired, separated combustion unit heaters are great for space heating applications. These models use outside air for combustion to prevent dirt, lint, dust or other contaminants in the indoor atmosphere from being burned. Model UDZ are available in 14 sizes ranging from 30,000 to 400,000 BTUH gas input and are approved for installation in the United States and Canada by ETL. Model UDZ unit heaters feature a two-tone black and white powder coated, scratch-resistant paint scheme with a single red louver. Each unit has clean rounded corners and edges with no visible screws or fasteners. The bottom of the unit is embossed with the Reznor logo. For air circulation, model UDZ uses an axial propellor fan.