Williams - High-Efficiency Direct-Vent Furnaces November 23, 2012 buildproducts A high-efficiency, low-profile furnace that may be installed nearly anywhere. Great for homes, apartments, offices, garages and room additions! Just minutes are all that is needed to warm up your room while enjoying the moneysaving, high-efficiency design, modern appearance and low-cost installation. Williams' high-efficiency direct-vent furnaces require no inside air for operation. making them an ideal choice for safe operation to add comfort to nearly anyplace heat is needed. Design Features Efficiency Ratings: - 7,400 Btu/hr. Series: 79% - 17,700 and 29,000 Btu/hr. Series: 82% Easy installation -- all vent material included Attractive, durable fresh-white finish. Natural and propane models Unique wall-mount design frees up floor space Small, low-profile vent size Sealed-combustion safety technology uses no inside room air for operation.