Dimensions: 16-7/8" W x 7-3/8" H x 18" L. Air Discharge: Rear, Side, Bottom or Top. 12 VDC, 5.6 amp, 30 lbs. The compact size, especially its low profile requiring only 7-1/2" vertical space, will provide greater flexibility in determining furnace location. The standardization of one compact framing dimension will allow you the option of installing either a 16, 20, 25, 31 or 35,000 BTU furnace. Designed to be installed and serviced from the exterior of the RV. Electronic ignition. Uses propane gas. Vent kit included. Door and Thermostat not included.