Thermometer Central stocks thousands of Lennox brand replacement parts and products for both residential and commercial applications. Lennox is a leading provider of innovative, home heating and cooling systems. Their high-efficiency, residential air conditioners, furnaces and HVAC systems help maximize comfort while reducing utility costs. Plus, Lennox air filters, humidifiers and dehumidifiers help create healthier and cleaner indoor environments. Lennox also offers packaged rooftops, split systems and other commercial heating and cooling technologies that deliver cost-effective comfort, along with planned and emergency equipment replacement options.