For a 60,000 BTUH water heater installed in a closet without a draft diverter, what is required for air intake?

For a water heater with an input of 60,000 BTUH installed in a closet without a draft diverter, it is crucial to ensure adequate air intake for the combustion process. The requirements for air intake are based on the size of the appliance and the space it occupies.

A 60,000 BTUH water heater generally requires a minimum of 60 square inches of free opening for fresh air intake to ensure a proper air supply for combustion. This requirement is designed to prevent any potential backdrafting or suffocation of the flame, which could lead to incomplete combustion, safety hazards, or decreased efficiency.

Additionally, having only a lower opening is sufficient in this context, as it is aimed at allowing fresh air to enter the combustion area from below. In scenarios where the installation also included upper venting or an exterior air source, those would be more relevant for different configurations or higher BTU inputs. The specific 60 square inch opening caters directly to the requirements for balancing airflow with the combustion demands of that particular water heater.