关于冷凝炉通风效率较简单效率在89%或以上的炉为“冷凝”或“调-冷凝”设计。冷凝炉使用二次热交换器来冷凝烟气中的水蒸气，并捕获原本会被送进烟囱的热量。由于烟道气是冷却的，它们可以用塑料管直接排放，而不是通过管道进入砖石或金属烟道。从热交换器排出的腐蚀性冷凝物。调节设计使用自动燃油阀来根据空间加热需求调节燃料燃烧量。由于添加了变速电机，这些熔炉产生的热量刚好满足所需，不像不复杂的单速或双速鼓风机电机设计。冷凝炉采用动力排气。它们通常配有一个密封燃烧燃烧器，从外部将燃烧空气吸入一个密封的室内进行燃烧。密封燃烧消除了当排气风扇(例如，抽油烟机风扇)给房子减压时燃烧烟气被拉进房子的风险。值得付出更高的代价。 Rapidly rising fuel prices make high-efficiency furnaces cost-effective in cold climates, despite the fact that they are more expensive than standard models. The cost of residential natural gas has nearly doubled since 2000. Fuel oil, a major source of home heat in the Northeast, has increased nearly fourfold in cost over the same period. In warm climates (for example, in Southern California, New Mexico, and the Gulf Coast states), upgrading from a standard furnace to a condensing furnace is not currently cost-effective. Furnaces also burn wood. Several manufacturers produce residential wood-fired hot-air furnaces, including Alpha American (Pallisade, MN), Blaze King Industries (Penticton, British Columbia), Fire Chief (Fenton, Mo.), Falcon Manufacturing (Winnipeg, Manitoba), Newmac (Debert, Nova Scotia), PSG (Quebec, Quebec), and U.S. Stove…