APPENDIX 6A. COOKTOPS AND OVENS: DETERMINATION OF ENERGY-USING 

COMPONENTS 

TABLE OF CONTENTS 

6A.1 INTRODUCTION .................................................................................................. 6A-1 

6A.2 METHODOLOGY FOR DISAGGREGATING ELECTRIC RANGE 

ANNUAL ENERGY CONSUMPTION................................................................. 6A-1 

6A.3 METHODOLOGY FOR ESTABLISHING GAS COOKING ENERGYUSING COMPONENTS ........................................................................................ 6A-4 

LIST OF TABLES 

Table 6A.2.1 Electric Cooking Products: Energy-Using Components............................ 6A-4 

Table 6A.3.1 Gas Cooking Products: Energy-Using Components.................................. 6A-6 

6A-i 

EERE-2006-STD-0127 COMMENT 64.2
APPENDIX 6A. COOKTOPS AND OVENS: DETERMINATION OF ENERGY-USING 

COMPONENTS 

6A.1 INTRODUCTION 

As presented in Chapter 6, section 6.4.1.2, based on recent survey data, DOE determined 

that the representative annual energy consumption of an electric range is 281.5 kWh per year. 

Because DOE’s analysis of cooking products consisted of analyzing oven and cooktop product 

classes, DOE had to disaggregate the range energy consumption into the portion allocated to the 

oven and the portion allocated to the cooktop. In addition, because oven and cooktop energy use 

may consist of several energy-using components (i.e., cooking, ignition, self-cleaning, and clock) 

and potential increases in efficiency may affect only a subset of these components, DOE had to 

further disaggregate the oven and cooktop energy consumption into its specific energy-using 

components. The following sections detail: (1) DOE’s method for disaggregating the 

representative electric range energy consumption into the various energy-using components of 

electric ovens and cooktops; and (2) DOE’s method for establishing the representative energy 

use of gas cooking product energy-using components based on the values that were determined 

for the electric cooking product energy-using components. 

6A.2 METHODOLOGY FOR DISAGGREGATING ELECTRIC RANGE 

ANNUAL ENERGY CONSUMPTION 

As noted above, DOE determined that the representative annual energy consumption of 

an electric range is 281.5 kWh per year. Based on the following equation, DOE assumed the 

energy consumption was equal to the sales weighted-average of standard and self-cleaning oven 

energy consumption plus the cooktop energy consumption. Also included is the clock power 

associated with electric ovens. 

UECelec cooking = 281.5kWh / yr

_ = MSe SC × (ECO _ SC + Ees× Se )+ (1 MSe SC )× ECO _ STD + ECA +(PCL ×8760× 0.001) 

where: 

UECelec cooking = Annual energy consumption of electric cooking (kWh/yr), 

MSeSC = Market share of electric ovens that are self-cleaning, 63.2%,1 

ECO_SC = Annual cooking energy consumption of self-cleaning electric ovens 

(kWh/yr), 

Ees = Typical self-cleaning energy consumption per cycle for electric selfcleaning ovens, 5.286 kWh (as reported in Chapter 6, Table 6.4.7), 

Se = Number of self-clean cycles per year for electric self-cleaning ovens 

according to the DOE test procedure, 4,2 

6A-1

EERE-2006-STD-0127 COMMENT 64.2
ECO_STD = Annual cooking energy consumption of standard electric ovens 

(kWh/yr), 

ECA = Annual energy consumption of electric cooktops (kWh/yr), 

PCL = Power input to clock (watts), 2,a 

8760 = Hours in a year, and 

0.001 = Conversion to convert watts in kW. 

DOE estimated the annual cooking energy consumption of electric self-cleaning ovens as 

a fraction of the cooking energy consumption of a standard electric oven. The annual cooking 

energy consumption of cooktops was also estimated as a fraction of the cooking energy 

consumption of standard ovens. These fractions were taken from the ratios of energy 

consumption as established by the DOE test procedure. The following equations represent the 

calculations used by DOE: 

ECO _ SC = ReSC _ STD × ECO _ STD

ECA = ReCT _ STD× ECO _ STD

where: 

ReSC_STD = Ratio of annual self-cleaning electric oven cooking energy to annul 

standard electric cooking energy, and 

ReCT_STD = Ratio of annul electric cooktop cooking energy to annual standard 

electric oven cooking energy. 

To calculate each of the above ratios, DOE took the annual useful cooking energy output 

values from the DOE test procedure and divided them by the baseline cooking efficiencies 

reported in Chapter 6, Table 6.4.1. For cooktops, this assumes that the ratio of the cooktop and 

oven annual useful cooking energy output value has not changed significantly over time, even 

though there has been a decrease in the annual energy consumption of electric cooking products. 

(OO EFFeoSC ) 

EFFeoSTD ) Re = 0.881 SC _ STD = (OO

EFFeCT (O ) CT

EFFeoSTD ) Re = 0.971 CT _ STD = (OO

where: 

a

 DOE assumed a clock power consumption of 2 watts for purposes of disaggregating the electric range annual 

energy consumption into its energy-using components. As reported in Chapter 6, the baseline clock power 

consumption for electric standard and self-cleaning ovens are 3.9 watts and 3.8 watts, respectively. 

6A-2

EERE-2006-STD-0127 COMMENT 64.2
_ _

_ _

OO = Annual useful cooking energy output for ovens according to the DOE 

test procedure, 29.3 kWh,2 

OCT = Annual useful cooking energy output for cooktops according to the DOE 

test procedure, 173.1 kWh, 2 

EFFeoSC = Cooking efficiency of the baseline self-cleaning electric oven, 13.79%, 

EFFeoSTD = Cooking efficiency of the baseline standard electric oven, 12.15%, and 

EFFeCT = Cooking efficiency of the baseline electric cooktop, 74.0%. 

The baseline cooking efficiency of electric cooktops (74%) is the sales weighted-average 

efficiency of coil and smooth cooktops. 

_ EFFeCT = MSeCOIL × EFFeCT _COIL + (1 MSeCOIL )× EFFeCT _ SMTH

where: 

MSeSC = Market share of electric cooktops that are coil, 46.3%,1 

EFFeCT_COIL = Cooking efficiency of the baseline electric coil cooktop, from the 

cost/efficiency table, 73.7%, and 

EFFeCT_SMTH = Cooking efficiency of the baseline electric smooth cooktop, from the 

cost/efficiency table, 74.2%. 

With both the annual cooking energy consumption of self-cleaning electric ovens and 

electric cooktops expressed as a function of standard electric oven annual cooking energy 

consumption, DOE solved for the standard electric oven annual cooking energy consumption by 

the using the following equation: 

ECO _ STD

281.5 MSeSC × Ees× S

_

e PCL ×8760× 0.001 

= 

MSeSC × ReSC _ STD +1 MSeSC + ReCT _ STD

281.5 63.2%×5.286× 4 2×8760× 0.001 

= = 132.4 kWh / yr _ 63.2%× 0.881+1 63.2% + 0.971 

With the standard electric oven annual cooking energy consumption established 

(EAO_STD), DOE solved for the self-cleaning electric oven and cooktop annual cooking energy 

consumption values by using the following equations: 

ECO _ SC = Re SC _ STD× ECO _ STD

= 0.881×132.4 = 116.6 kWh / yr

ECA = ReCT _ STD × ECO _ STD

= 0.971×132.4 = 128.3kWh / yr

6A-3 

EERE-2006-STD-0127 COMMENT 64.2
Table 6A.2.1 summarizes the energy-using components of electric cooking products. 

Also provided are the annual useful cooking energy output values—one set based on the DOE 

test procedure and another set deduced from the lower annual energy consumption values. 

Table 6A.2.1 Electric Cooking Products: Energy-Using Components 

Energy-Using Components Cooktop Standard Oven Self-Cleaning Oven 

Cooking Efficiency 74.0% 12.15% 13.79% 

Cooking Energy (kWh/yr) 128.2 132.4 116.6 

Self-Cleaning Energy (kWh/yr) 21.1 

Clock (kWh/yr)* 34.2 33.3 

Total (kWh/yr) 128.2 166.5 171.0 

Annual Useful Cooking Energy Output (OCT for cooktops; OO for ovens)

 Current DOE test procedure (kWh) 173.1 29.3 29.3 

Based on electric range annual 

cooking energy of 281.5 kWh/yr 

(kWh) 

94.8 16.1 16.1 

* Clock energy based on clock power of 3.9 W for standard ovens and 3.8 W for self-cleaning ovens. 

6A.3 METHODOLOGY FOR ESTABLISHING GAS COOKING ENERGYUSING COMPONENTS 

DOE estimated the annual energy consumption of gas cooking products based on the 

lower (revised) annual useful cooking energy output values that DOE deduced from the electric 

range annual energy consumption of 281.5 kWh per year. As represented by the following 

equations, DOE assumed that the ratio of the revised-to-current annual useful energy output 

values for electric cooking products applied to gas cooking products as well: 

OO _ ELEC _REV 16.1kWh

OO _GAS _REV = OO _GAS _ DOE × 

OO _ ELEC _ DOE

= 88.8kBtu× 

29.3kWh = 48.7 kBtu

OCT _ELEC _REV 94.8kWh

OCT _GAS _REV = OCT _GAS _ DOE × = 527.6 kBtu× = 288.9 kBtu OCT _ELEC _ DOE 173.1kWh

where: 

OO_GAS_REV = Revised annual useful cooking energy output for gas ovens, 

OO_GAS_DOE = DOE test procedure annual useful cooking energy output for gas ovens, 

OO_ELEC_REV = Revised annual useful cooking energy output for electric ovens, 

OO_ELEC_DOE = DOE test procedure annual useful cooking energy output for electric 

ovens, 

OCT_GAS_REV = Revised annual useful cooking energy output for gas cooktops, 

6A-4

EERE-2006-STD-0127 COMMENT 64.2
OCT_GAS_DOE = DOE test procedure annual useful cooking energy output for gas 

cooktops, 

OCT_ELEC_REV = Revised annual useful cooking energy output for electric cooktop, and 

OCT_ELEC_DOE = DOE test procedure annual useful cooking energy output for electric 

cooktops. 

With the revised annual useful cooking output values known for gas cooking products, 

DOE used the following test procedure equations to calculate the annual cooking energy 

consumption of gas cooking products. In the equations below, DOE used the baseline cooking 

efficiencies reported in Chapter 6, Table 6.4.1. 

OO _GAS _REV 48.7 kBtu

ECO _ SC _GAS = 

EFFgoSC

= 7.13% = 683.5kBtu / yr

OO _GAS _REV 48.7 kBtu

ECO _ STD _GAS = 

EFFgo = 5.92%

= 822.6 kBtu / yr

STD

OCT _GAS _REV 288.9 kBtu

ECC _GAS = 

EFFgCT

= 

39.9%

= 724.4 kBtu / yr

where: 

ECO_SC_GAS = Annual cooking energy consumption of gas self-cleaning ovens, 

EFFgoSC = Cooking efficiency of the baseline self-cleaning gas oven, 7.13%, 

ECO_STD_GAS = Annual cooking energy consumption of gas standard ovens, 

EFFgoSTD = Cooking efficiency of the baseline standard gas oven, 5.92%, 

ECC_GAS = Annual cooking energy consumption of gas cooktops, and 

EFFgCT = Cooking efficiency of the baseline gas cooktop, 39.9%. 

Table 6A.3.1 summarizes the energy-using components of gas cooking products. Also 

provided are the annual useful cooking energy output values—one set based on the DOE test 

procedure and the other based on the revised set of values. Ignition, self-cleaning, and clock 

energy consumption values are described and reported in Chapter 6, Tables 6.4.5, 6.4.8, and 

6.4.9 for gas cooktops, standard ovens, and self-cleaning ovens, respectively. 

6A-5

EERE-2006-STD-0127 COMMENT 64.2
Table 6A.3.1 Gas Cooking Products: Energy-Using Components 

Energy-Using Components 

Cooktop Standard Oven SelfCleaning 

Oven 

With 

pilot 

Without 

pilot 

With 

pilot 

Without 

pilot 

Cooking Efficiency 39.9% 39.9% 5.92% 5.92% 7.13% 

Cooking Energy (MMBtu/yr) 0.72 0.72 0.82 0.82 0.68 

Self-Cleaning Energy

 Gas (MMBtu/yr) 0.17 

 Electric (kWh/yr) 0.7 

Ignition 

 Gas (MMBtu/yr) 2.02 1.01 

 Electric (kWh/yr) 21.1 21.1 

Clock (kWh/yr)* 31.5 

Total

 Gas (MMBtu/yr) 2.74 0.72 1.83 0.82 0.85 

 Electric (kWh/yr) 21.1 55.1 

Annual Useful Cooking Energy Output (OCT for cooktops; OO for ovens)

 Current DOE test procedure (kBtu) 527.6 88.8 88.8 

Revised values (kBtu) 288.9 48.7 48.7 

* Clock energy based on clock power of 3.6 W for self-cleaning ovens. 

6A-6

EERE-2006-STD-0127 COMMENT 64.2
REFERENCES 

1 Association of Home Appliance Manufacturers. AHAM Data on Cooking Products for 

Efficiency Standards Rulemaking, August 23, 2006. Letter to Building Technologies 

Program, U.S. Department of Energy. 

2 U.S. Office of the Federal Register. Code of Federal Regulations, Title 10, Energy. Part 430, 

Subpart B, Appendix I: Uniform Test Method for Measuring the Energy Consumption of 

Conventional Ranges, Conventional Cooking Tops, Conventional Ovens, and Microwave 

Ovens, 2006. Washington, DC. 

6A-7

EERE-2006-STD-0127 COMMENT 64.2