Sealed combustion chambers enhance safety and efficiency of gas furnaces. By isolating combustion within the appliance, natural gas is burned more efficiently and there is less risk of contaminating surrounding air. When sealed combustion appliances are not an option, homes must pass a Combustion Appliance Zone test. This test ensures that combustion appliances have access to enough fresh air to properly exhaust combustion air.

For more information about Combustion Appliance Zone testing and Energy Trust requirements, download the EPS Field Guide or watch the Specific Equipment Requirements training module on our online training page.