This standard provides test procedures for determining the efficiency and hot water delivery capability of the waterheating equipment to which it applies. This standard does not apply to gas-fired service waterheating equipment that meets all of the following: a. has a storage capacity of less than two gallons@ b. is designated to deliver water at a controlled temperature of less than 180??(82??@ and c. has an input rating less than 200@000 Btu/h (59 kW). PURPOSE The purpose of this standard is to provide test procedures for rating directly heated commercial-service water-heating equipment.