Wash. Admin. Code § 51-11C-403326 - Table C403.3.2(6)-Minimum efficiency requirements-Gas-fired and oil-fired boilers

State Regulations
Compare

Table C403.3.2(6)

Gas- and Oil-Fired Boilers-Minimum Efficiency Requirements

Equipment Type^a	Subcategory or Rating Condition	Size Category (Input)	Minimum Efficiency	Test Procedure^a
Boilers, hot water	Gas-fired	< 300,000 Btu/h^g,h for applications outside the U.S.	82% AFUE	DOE 10 C.F.R. 430 Appendix N
		[GREATER THAN EQUAL TO] 300,000 Btu/h and [LESS THAN EQUAL TO] 2,500,000 Btu/h^e	84% E_t^d	DOE 10 C.F.R. 431.86
		< 2,500,000 Btu/h and [LESS THAN EQUAL TO] 10,000,000 Btu/h^b	85% E_t^d
		10,000,000 Btu/h^b	82% E_c^c
	Oil-fired^f	< 300,000 Btu/h^g,h	84% AFUE	DOE 10 C.F.R. 430 Appendix N
		[GREATER THAN EQUAL TO] 300,000 Btu/h and [LESS THAN EQUAL TO] 2,500,000 Btu/h^e	87% E_t^d	DOE 10 C.F.R. 431.86
		2,500,000 Btu/h^b	88% E_c^c
		10,000,000 Btu/h^b	84% E_c^d
Boilers, steam	Gas-fired	< 300,000 Btu/h^g	81% AFUE	DOE 10 C.F.R. 430 Appendix N
	Gas-fired - all, except natural draft	[GREATER THAN EQUAL TO] 300,000 Btu/h and [LESS THAN EQUAL TO] 2,500,000 Btu/h^b	82% E_t^d	DOE 10 C.F.R. 431.86
		2,500,000 Btu/h^a	79% E_t^d
		10,000,000 Btu/h^b	79% E_t^d
	Gas-fired - natural draft	[GREATER THAN EQUAL TO] 300,000 Btu/h and [LESS THAN EQUAL TO] 2,500,000 Btu/h^b	81% E_t^d
		2,500,000 Btu/h^b	82% E_t^d
		10,000,000 Btu/h^b	79% E_t^d
	Oil-fired^f	< 300,000 Btu/h	82% AFUE	DOE 10 C.F.R. 430 Appendix N
		[GREATER THAN EQUAL TO] 300,000 Btu/h and [LESS THAN EQUAL TO] 2,500,000 Btu/h^b	84% E_t^d	DOE 10 C.F.R. 431.86
		2,500,000 Btu/h^b	85% E_t^d
		10,000,000 Btu/h^b	81% E_t^d

For SI: 1 British thermal unit per hour = 0.2931 W.

^a Chapter 6 contains a complete specification of the referenced standards, which include test procedures, including the reference year version of the test procedure.

^b These requirements apply to boilers with rated input of 8,000,000 Btu/h or less that are not packaged boilers and to all packaged boilers. Minimum efficiency requirements for boilers cover all capacities of packaged boilers.

^c E_c = Combustion efficiency (100 percent less flue losses).

^d E_t = Thermal efficiency.

^e Maximum capacity - Minimum and maximum ratings as provided for and allowed by the unit's controls.

^f Includes oil-fired (residual).

^g Boilers shall not be equipped with a constant burning pilot light.

^h A boiler not equipped with a tankless domestic water heating coil shall be equipped with an automatic means for adjusting the temperature of the water such that an incremental change in inferred heat load produces a corresponding incremental change in the temperature of the water supplied.

ⁱ This table is a replica of ASHRAE 90.1 Table 6.8.1-6 Gas- and Oil-Fired Boilers-Minimum Efficiency Requirements.

Notes

Wash. Admin. Code § 51-11C-403326

Adopted by WSR 22-14-091, Filed 7/1/2022, effective 7/1/2023

State regulations are updated quarterly; we currently have two versions available. Below is a comparison between our most recent version and the prior quarterly release. More comparison features will be added as we have more versions to compare.