What is the maximum input rating for a single wall-mounted unvented room heater installed in a bedroom?

The maximum input rating for a single wall-mounted unvented room heater installed in a bedroom is 20,000 BTUs. This limit is set primarily for safety reasons, as unvented heaters operate by burning fuel and releasing combustion gases into the living space. Excessive BTU ratings can lead to increased levels of carbon monoxide and other harmful gases, posing a risk to the occupants of the room, particularly in a confined space such as a bedroom.

Limiting the input rating to 20,000 BTUs ensures that the heater can provide sufficient warmth without creating an unsafe environment. This guideline helps to maintain a balance between comfort and safety, ensuring that combustion byproducts are manageable and that there's an adequate supply of fresh air. Regulatory codes and standards are designed to protect individuals from the hazards associated with unvented heating appliances, especially in sleeping areas.