关于冷凝炉排气效率高的炉很简单效率达到89%或以上的是“冷凝”或“调节-冷凝”设计。冷凝炉使用一个二级热交换器来冷凝烟气中的水蒸气，并捕获原本会被送往烟囱的热量。由于烟道气体是冷却的，它们可以用塑料管道直接排空，而不是用管道排入砖石或金属烟道。从热交换器中排出有腐蚀性的冷凝水。调节设计采用自动燃油阀来根据空间加热需求调节燃油燃烧量。随着变速电机的加入，这些熔炉产生的热量正好是所需要的，不像简单设计的单速或双速风机电机。冷凝炉是动力排气管。它们通常配备一个密封燃烧燃烧器，将燃烧空气从外部吸进一个密封的燃烧室，在那里燃烧。密封燃烧消除了当排气扇(例如抽油烟机)给房屋减压时，燃烧烟雾可能被带入房屋的风险。更高的成本是值得的。 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…