This is a revision of ANSI/ASHRAE Standard 118.1-2003. The changes made for the 2008 revision were: 1) references were updated, 2) value conversions were made consistent in Sections 7.2.2 and 7.7.4.1, and 3) SI unit values were added where needed in Section 10.2.31.

The purpose of this standard is to provide test procedures for rating directly heated commercial-service water-heating equipment. This standard provides test procedures for determiningthe efficiency and hot water delivery capability of the water-heating equipment to which it applies. This standard applies to electric resistance, electric air-source heat pump, gas-fired, and oil-fired water-heatingequipment, including hot water supply boilers with input ratings less than 12,500,000 Btu/h (3660 kW) and greater than:

Electric Resistance 12 kW
Electric Heat Pump 6 kW (including all 3 phase regardlessof input)
Gas-Fired 75,000 Btu/h (22 kW)
Oil-Fired 105,000 Btu/h (31 kW)

This standard does not apply to gas-fired service water-heating equipment that meets all of the following: 1) has a storage capacity of less than two gallons, 2) is designated to deliver water at a controlled temperature of less than 180°F (82°C), and 3) has an input rating less than 200,000 Btu/h (59 kW).

Units: Dual