True or False: During the air testing process, combustion appliances must be sealed from living spaces.

The statement is true because during the air testing process, it is crucial to ensure that combustion appliances are sealed from living spaces. This is necessary to prevent potential backdrafting of combustion gases, which can pose health risks to occupants. If combustion appliances, such as gas furnaces or water heaters, are not properly sealed off, the negative pressure created during the air test can cause exhaust gases to flow back into the living space instead of venting outside.

By sealing these appliances, testers ensure that the air leak measurement reflects only the building envelope and not the potential impact of these appliances. This procedure is part of maintaining safety and accuracy during the air testing process. It highlights the importance of adhering to building codes and safety standards, as well as ensuring that the testing environment is representative of normal operating conditions without risks to health and safety.