In which area is combustion air typically sourced from for gas appliances?

For gas appliances, combustion air is typically sourced from living spaces. This is primarily because living spaces are designed to allow for proper air circulation, which is essential for appliances that require oxygen for combustion. Using air from living areas ensures that enough fresh air is available to support safe and efficient burning of gas.

Inadequate combustion air can lead to incomplete combustion, which may result in the production of carbon monoxide, a hazardous gas. By sourcing air from living spaces, building codes and safety standards are generally followed, promoting both safety and efficiency in gas appliance operation.

The other options, such as attics, closets, and basements, may not provide a reliable source of combustion air because they can be more sealed off or may not have the same air circulation characteristics needed for effective combustion. This can lead to safety risks and performance issues with gas appliances.