What must be the least width of the access opening for appliances under floors?

The least width of the access opening for appliances under floors is established to ensure that there is sufficient space for both the installation and maintenance of equipment. A width of 20 inches allows technicians and service personnel adequate room to maneuver tools and equipment, performing necessary inspections or repairs without significant risk of physical injury or damage to the system being serviced. This dimension is based on industry best practices and aligns with safety considerations when accessing appliances that may be situated in confined spaces.

A width of 20 inches has been recognized as a practical standard that balances accessibility with the structural requirements of the flooring. This standard is designed not only for ease of access but also to facilitate compliance with manufacturer installation requirements and local codes, ensuring that appliances can be safely and effectively maintained throughout their service life.