From where must combustion air be drawn for gas appliances in bedrooms?

Combustion air must be drawn from outdoors for gas appliances installed in bedrooms to ensure safety and efficiency. This regulation is primarily based on the need to prevent the accumulation of carbon monoxide and other harmful gases that can result from the combustion process. By sourcing air from outside, the appliances have a constant supply of fresh air necessary for proper combustion, reducing the risks associated with inadequate ventilation and the potential for backdrafting, where exhaust gases could flow back into the living space.

Choosing outdoor air also minimizes the risk of fire hazards, as bedrooms often have lower ventilation rates compared to other areas of a home. This precaution is critical in ensuring that gases produced during combustion do not build up in enclosed areas, thus maintaining occupant safety.

Ventilating from adjacent rooms might not provide sufficient fresh air, especially if those rooms are also occupied or have appliances running, while drawing air from the attic or basement could lead to similar risks related to poor air quality and potential hazardous gas buildup.