The following definitions apply for purposes of this subpart E, and of subparts A and J through M of this part. Any words or terms not defined in this section or elsewhere in this part shall be defined as provided in 42 U.S.C. 6311.

Basic model means all commercial packaged boilers manufactured by one manufacturer within a single equipment class having the same primary energy source (e.g., gas or oil) and that have essentially identical electrical, physical and functional characteristics that affect energy efficiency.

Btu/h or Btu/hr means British thermal units per hour.

Combustion efficiency for a commercial packaged boiler is a measurement of how much of the fuel input energy is converted to useful heat in combustion and is calculated as 100-percent minus percent losses due to dry flue gas, incomplete combustion, and moisture formed by combustion of hydrogen, as determined with the test procedures prescribed under §431.86 of this chapter.

Commercial packaged boiler means a packaged boiler that meets all of the following criteria:

(1) Has rated input of 300,000 Btu/h or greater;

(2) Is, to any significant extent, distributed in commerce for space conditioning and/or service water heating in buildings but does not meet the definition of “hot water supply boiler” in this part;

(3) Does not meet the definition of “field-constructed” in this section; and

(4) Is designed to:

(i) Operate at a steam pressure at or below 15 psig;

(ii) Operate at or below a water pressure of 160 psig and water temperature of 250 °F; or

(iii) Operate at the conditions specified in both paragraphs (4)(i) and (ii) of this definition.

Condensing boiler means a commercial packaged boiler that condenses part of the water vapor in the flue gases, and that includes a means of collecting and draining this condensate from its heat exchanger section.

Field-constructed means custom-designed equipment that requires welding of structural components in the field during installation. For the purposes of this definition, welding does not include attachment using mechanical fasteners or brazing; any jackets, shrouds, venting, burner, or burner mounting hardware are not structural components.

Flue condensate means liquid formed by the condensation of moisture in the flue gases.

Fuel input rate for a commercial packaged boiler means the measured rate at which the commercial packaged boiler uses energy and is determined using test procedures prescribed under §431.86 of this chapter.

Manufacturer of a commercial packaged boiler means any person who manufactures, produces, assembles or imports such a boiler, including any person who:

(1) Manufactures, produces, assembles or imports a commercial packaged boiler in its entirety;

(2) Manufactures, produces, assembles or imports a commercial packaged boiler in part, and specifies or approves the boiler's components, including burners or other components produced by others, as for example by specifying such components in a catalogue by make and model number or parts number; or

(3) Is any vendor or installer who sells a commercial packaged boiler that consists of a combination of components that is not specified or approved by a person described in paragraph (1) or (2) of this definition.

Packaged boiler means a boiler that is shipped complete with heating equipment, mechanical draft equipment, and automatic controls and is usually shipped in one or more sections. If the boiler is shipped in more than one section, the sections may be produced by more than one manufacturer, and may be originated or shipped at different times and from more than one location.

Rated input means the maximum rate at which the commercial packaged boiler has been rated to use energy as indicated by the nameplate and in the manual shipped with the commercial packaged boiler.

Thermal efficiency for a commercial packaged boiler is determined using test procedures prescribed under §431.86 and is the ratio of the heat absorbed by the water or the water and steam to the higher heating value in the fuel burned.

[69 FR 61960, Oct. 21, 2004, as amended at 74 FR 36354, July 22, 2009; 76 FR 12503, Mar. 7, 2011; 78 FR 79598, Dec. 31, 2013; 81 FR 89304, Dec. 9, 2016]