Testing method for measuring energy consumption and determining efficiencies of gas-fired and fuel oil-fired water heaters

1.1
This Standard describes the test procedures required to perform a 24 h simulated-use test. This Standard also provides the calculations required to determine the first-hour rating, maximum flow rate, recovery efficiency, standby loss, daily water heating energy consumption, uniform energy factor, and annual energy consumption for gas-fired and fuel oil-fired water heaters.

1.2
This Standard applies to:

a) Gas-fired storage water heaters

• i) with rated storage capacity up to and including 454 L (120 US gal);
  
  ii) having rated inputs up to and including 30.77 kW (105 000 Btu/h); and
  
  iii) designed to provide outlet hot water at a controlled temperature up to and including 82 °C (180°F);

b) Fuel oil-fired storage water heaters

• i) with rated storage capacity up to and including 454 L (120 US gal);
  
  ii) having rated inputs up to and including 41.03 kW (140,000 Btu/h); and
  
  iii) designed to provide outlet hot water at a controlled temperature up to and including 82 °C (180°F);

c) Gas-fired instantaneous water heaters

• i) with rated storage capacity up to and including 7.6 L (2 US gal);
  
  ii) having rated inputs up to and including 73.25 kW (250 000 Btu/h); and
  
  iii) designed to provide outlet hot water at a controlled temperature up to and including 82 °C (180°F); and

d) Oil-fired instantaneous water heaters

• i) with rated storage capacity up to and including 7.6 L (2 US gal);
  
  ii) having rated inputs up to and including 61.53 kW (210 000 Btu/h); and
  
  iii) designed to provide outlet hot water at a controlled temperature up to and including 82 °C (180 °F).

1.3
The tests contained in this Standard provide a standardized method of comparing performance and efficiency.

1.4
The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.

1.5
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application