Suburban SF-35FQ SF-35VHFQ 35,000 BTU Ducted RV Furnace 2587AFeatures The SF FQ series furnaces from Suburban provide maximum heating performance in a ducted unit for increased design flexibility in mid size and large RVs. This unit can be installed horizontally only. Specifications Dimensions: 7. 5" x 17" x 20"Weight: 29 poundsBTU h: Inputs 35,000Voltage: 12Amp Draw: 8Ducts Required: 4 4"Required Return (in): 55" Uses LP (propane) for fuel Replaces: SF35F, SF 35VHFQ, SF 25FQ, SF25F, SF25VHFQ, SF 30FQ, SF30F,