High-Efficient Direct-Vent Wall Furnace Size: 40,000 Btu, Fuel: Liquid Propane Go to amazon.com Related posts Top recommendation for furnaces 40,000 btus FeatureModel #: DV40ELPBTU Input: 40,000BTU output: 40,000Hot surface ignitionDimensions: 15.75" (D) x 37" (W) x 26" (H) DescriptionDV-40E Size: 40,000 Btu, Fuel: Liquid Propane Features: -High efficient DV furnace.-Available in liquid propane and natural gas.-Electronic thermistor. Specifications: -Available in 55000 BTU and 40000 BTU.