Is a mechanical room containing a 65,000 btu/hr water heater and a 90,000 btu/hr furnace considered a confined space if the room meets average dimensional requirements?

A mechanical room is classified as a confined space based on specific criteria related to its volume and the presence of combustion appliances. For a space to be considered confined, it typically must fail to meet the minimum volume requirement necessary for the proper functioning of combustion appliances like water heaters and furnaces.

When calculating whether a space is confined, the total BTU/hr of all fuel-burning appliances is a critical factor. In this scenario, the combined total outputs (65,000 BTU/hr for the water heater and 90,000 BTU/hr for the furnace, totaling 155,000 BTU/hr) must be considered against the cubic footage of the room. If the dimensions of the room fall short of the required volume for adequate air supply for combustion processes, it would indeed be categorized as a confined space.

In this case, the answer confirms that if the room meets average dimensional requirements but still does not provide enough volume for the gas appliances to operate safely, it would be classified as a confined space. This classification necessitates appropriate ventilation to prevent hazardous conditions, emphasizing the need for compliance with local codes regarding air supply to fuel-burning equipment. This understanding reinforces the importance of correct space evaluation in HVAC practices.