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WACs > Title 51 > Chapter 51-11C > Section 51-11C-403234











51-11C-403233    

51-11C-403235







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WAC 51-11C-403234









Table C403.2.3(4)—Minimum efficiency requirements—Warm air furnaces and unit heaters.









Table 403.2.3(4)
Warm Air Furnaces and Combination Warm Air Furnaces/Air-Conditioning Units, Warm Air Duct Furnaces and Unit Heaters, Minimum Efficiency Requirements

Equipment Type Size Category (Input) Subcategory or Rating Condition Minimum Efficiencyd, e Test Procedurea

Warm air furnaces, gas fired < 225,000 Btu/h — 78% AFUE or 80% Etc
DOE 10 C.F.R. Part 430 or ANSI Z21.47

  ≥ 225,000 Btu/h Maximum capacityc
80% Etf
ANSI Z21.47

Warm air furnaces, oil fired < 225,000 Btu/h — 78% AFUE or 80% Etc
DOE 10 C.F.R. Part 430 or UL 727

  ≥ 225,000 Btu/h Maximum capacityb
81% Etg
UL 727

Warm air duct furnaces, gas fired All capacities Maximum capacityb
80% Ec
ANSI Z83.8

Warm air unit heaters, gas fired All capacities Maximum capacityb
80% Ec
ANSI Z83.8

Warm air unit heaters, oil fired All capacities Maximum capacityb
80% Ec
UL 731

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

a
Chapter 6 of the referenced standard contains a complete specification of the referenced test procedure, including the referenced year version of the test procedure.

b
Minimum and maximum ratings as provided for and allowed by the unit's controls.

c
Combination units not covered by the National Appliance Energy Conservation Act of 1987 (NAECA) (3-phase power or cooling capacity greater than or equal to 65,000 Btu/h [19 kW]) shall comply with either rating.

 
d Et
= Thermal efficiency. See test procedure for detailed discussion.

 
e Ec
= Combustion efficiency (100% less flue losses). See test procedure for detailed discussion.

 
f Ec
= Combustion efficiency. Units must also include an IID, have jackets not exceeding 0.75 percent of the input rating, and have either power venting or a flue damper. A vent damper is an acceptable alternative to a flue damper for those furnaces where combustion air is drawn from the conditioned space.

 
g Et
= Thermal efficiency. Units must also include an IID, have jacket losses not exceeding 0.75 percent of the input rating, and have either power venting or a flue damper. A vent damper is an acceptable alternative to a flue damper for those furnaces where combustion air is drawn from the conditioned space.

[Statutory Authority: RCW 19.27A.020, 19.27A.025 and chapters 19.27 and 34.05 RCW. WSR 13-04-056, § 51-11C-403234, filed 2/1/13, effective 7/1/13.]

Reviser's note: The brackets and enclosed material in the text of the above section occurred in the copy filed by the agency.