Offering an impressive 92.6% efficiency, the Energy Pro gas fireplace is a 36,000 Btu furnace that provides ambiance plus heat. A built-in heat exchanger captures fireplace heat and disperses it throughout the home, either through the HVAC ducts or ducts connected only to the fireplace. Installed cost: about $8,400. Hearth & Home Technologies, 888.427.3973, heatnglo.com
