From which areas may fuel-fired water heaters NOT obtain combustion air?

Fuel-fired water heaters require proper combustion air to function safely and efficiently. According to building codes and safety standards, certain areas are restricted from being used as sources of combustion air due to the potential for hazardous conditions or inadequate ventilation.

Sleeping rooms, bathrooms, and toilet rooms are designated as areas where combustion air cannot be obtained primarily because they are considered spaces that should maintain a safe and comfortable environment. These rooms may contain flammable materials or sensitive occupants, and introducing combustion air from these areas could lead to the accumulation of harmful gases like carbon monoxide, especially if there is inadequate ventilation. Additionally, these rooms typically have limited air flow, which is not conducive to the combustion process.

Thus, by ensuring that fuel-fired water heaters do not obtain combustion air from these sensitive areas, safety is prioritized, minimizing the risk of accidents related to combustion air supply while also protecting the health of the building's occupants.