This page lists the variables used in each Inputs Verifier Tool (IVT) equation in subpart C. This information is intended primarily for XML uploaders to enable them to understand how each IVT equation is calculated and to identify sources for the constants, default values, and lookup values needed to solve the equations.
Click the links for the equations below to view the variables used in the IVT calculations:
- Equation C-1: Annual CO2 Mass Emissions for the Specific Fuel Type for Tier 1
- Equation C-1a: Annual CO2 Mass Emissions from Natural Gas Combustion for Tier 1 - Therms
- Equation C-1b: Annual CO2 Mass Emissions from Natural Gas Combustion for Tier 1 - MMBtu
- Equation C-2a: Annual CO2 mass emissions for a specific fuel type for Tier 2
- Equation C-2b: Weighted Annual Average High Heat Value of the Fuel
- Equation C-2c: Annual CO2 Mass Emissions from MSW or Solid Fuel Combustion
- Equation C-3: Annual CO2 Mass Emissions from the Combustion of the Specific Solid Fuel for Tier 3
- Equation C-4: Annual CO2 Mass Emissions from the Combustion of the Specific Liquid Fuel for Tier 3
- Equation C-5: Annual CO2 Mass Emissions from the Combustion of the Specific Gaseous Fuel for Tier 3
Equation C-8: Annual CH4 or N2O Emissions from the Combustion of a Particular Type of Fuel for which Tier 1 or Tier 3 Is Used to Calculate CO2 Emissions
- Equation C-8a: Annual CH4 or N2O Emissions from the Combustion of Natural Gas - Therms
- Equation C-8b: Annual CH4 or N2O Emissions from the Combustion of Natural Gas - mmBtu
- Equation C-13: Annual Volume of CO2 Emitted from Combustion of a Particular Fossil Fuel
Equation C-1: Annual CO2 Mass Emissions for the Specific Fuel Type for Tier 1
Equation C-1 calculates annual CO2 mass emissions for the specific fuel type for Tier 1
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions for the specific fuel type | metric tons | Output |
Fuel | Mass or volume of fuel combusted per year, from company records as defined in §98.6 | short tons for solid fuel volume in standard cubic feet for gaseous fuel volume in gallons for liquid fuel | User input |
HHV | Default high heat value of the fuel, from Table C-1 of this subpart | mmBtu per mass or mmBtu per volume, as applicable | |
EF | Fuel-specific default CO2 emission factor, from Table C-1 of this subpart | kg CO2/mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-1a: Annual CO2 Mass Emissions from Natural Gas Combustion for Tier 1 - Therms
Equation C-1a calculates annual CO2 mass emissions from natural gas combustion when natural gas consumption in billing records is expressed in therms.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from natural gas combustion | metric tons | Output |
Gas | Annual natural gas usage, from billing records | therms | User input |
EF | Fuel-specific default CO2 emission factor for natural gas, from Table C-1 of this subpart | kg CO2/mmBtu | |
0.1 | Conversion factor from therms to mmBtu | mmBtu/therm | 0.1 |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-1b: Annual CO2 Mass Emissions from Natural Gas Combustion for Tier 1 - mmBtu
Equation C-1b calculates annual CO2 mass emissions from natural gas combustion when natural gas consumption in billing records is expressed in mmBtu.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from natural gas combustion | metric tons | Output |
Gas | Annual natural gas usage, from billing records | mmBtu | User input |
EF | Fuel-specific default CO2 emission factor for natural gas, from Table C-1 of this subpart | kg CO2/mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-2a: Annual CO2 mass emissions for a specific fuel type for Tier 2
Equation C-2a calculates annual CO2 mass emissions for a specific fuel type for Tier 2.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions for a specific fuel type | metric tons | Output |
Fuel | Mass or volume of the fuel combusted during the year, from company records as defined in §98.6 | short tons for solid fuel volume in standard cubic feet for gaseous fuel volume in gallons for liquid fuel | User input |
HHV | Annual average high heat value of the fuel | mmBtu per mass or volume. The average HHV shall be calculated according to the requirements of paragraph (a)(2)(ii) of this section | User input |
EF | Fuel-specific default CO2 emission factor, from Table C-1 of this subpart | kg CO2/mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-2b: Weighted Annual Average High Heat Value of the Fuel
Equation C-2b calculates the weighted annual average high heat value of the fuel.
The table below defines the parameters in this equation. Equation C-2b does not include constants, default values, or lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
(HHV)annual | Weighted annual average high heat value of the fuel | mmBtu per mass or volume | Output |
(HHV)I | Measured high heat value of the fuel, for month “i” (which may be the arithmetic average of multiple determinations), or, if applicable, an appropriate substitute data value | mmBtu per mass or volume | User input |
(Fuel)I | Mass or volume of the fuel combusted during month “i,” from company records | short tons for solid fuel volume in standard cubic feet for gaseous fuel volume in gallons for liquid fuel | User input |
n | Number of months in the year that the fuel is burned in the unit | - | 1-12 |
Equation C-2c: Annual CO2 Mass Emissions from MSW or Solid Fuel Combustion
Equation C-2c calculates annual CO2 mass emissions from MSW or solid fuel combustion.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from MSW or solid fuel combustion | metric tons | Output |
Steam | Total mass of steam generated by MSW or solid fuel combustion during the reporting year | lb steam | User input |
B | Ratio of the boiler's maximum rated heat input capacity to its design rated steam output capacity | mmBtu/lb steam | User input |
EF | Fuel-specific default CO2 emission factor, from Table C-1 of this subpart | kg CO2/mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-3: Annual CO2 Mass Emissions from the Combustion of the Specific Solid Fuel for Tier 3
Equation C-3 calculates annual CO2 mass emissions from the combustion of the specific solid fuel.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from the combustion of the specific solid fuel | metric tons | Output |
Fuel | Annual mass of the solid fuel combusted, from company records as defined in §98.6 | short tons | User input |
CC | Annual average carbon content of the solid fuel | percent by weight, expressed as a decimal fraction, e.g., 95% = 0.95 | User input
|
44/12 | Ratio of molecular weights, CO2 to carbon | - | 44/12 |
0.91 | Conversion factor from short tons to metric tons | - | 0.91 |
Equation C-4: Annual CO2 Mass Emissions from the Combustion of the Specific Liquid Fuel for Tier 3
Equation C-4 calculates annual CO2 mass emissions from the combustion of the specific liquid fuel.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from the combustion of the specific liquid fuel | metric tons | Output |
Fuel | Annual volume of the liquid fuel combusted | gallons | User input |
CC | Annual average carbon content of the liquid fuel | kg C per gallon of fuel | User input |
44/12 | Ratio of molecular weights, CO2 to carbon | - | 44/12 |
0.001 | Conversion factor from kg to metric tons | - | 0.001 |
Equation C-5: Annual CO2 Mass Emissions from the Combustion of the Specific Gaseous Fuel for Tier 3
Equation C-5 calculates annual CO2 mass emissions from combustion of the specific gaseous fuel.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CO2 | Annual CO2 mass emissions from combustion of the specific gaseous fuel | metric tons | Output |
Fuel | Annual volume of the gaseous fuel combusted | scf | User input |
CC | Annual average carbon content of the gaseous fuel | kg C per kg of fuel | User input |
MW | Annual average molecular weight of the gaseous fuel | kg/kg-mole | User input |
MVC | Molar volume conversion factor at standard conditions, as defined in §98.6 | scf per kg mole | 849.5 @ 68°F, or 836.6 @ 60 °F |
44/12 | Ratio of molecular weights, CO2 to carbon | - | 44/12 |
0.001 | Conversion factor from kg to metric tons | - | 0.001 |
Equation C-8: Annual CH4 or N2O Emissions from the Combustion of a Particular Type of Fuel for which Tier 1 or Tier 3 Is Used to Calculate CO2 Emissions
Equation C-8 calculates annual CH4 or N2O emissions from the combustion of a particular type of fuel for which Tier 1 or Tier 3 Is Used to Calculate CO2 Emissions
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of a particular type of fuel | metric tons | Output |
Fuel | Mass or volume of the fuel combusted, either from company records or directly measured by a fuel flow meter, as applicable | mass or volume per year | User Input |
HHV | Default high heat value of the fuel from Table C-1 of this subpart; alternatively, for Tier 3, if actual HHV data are available for the reporting year, you may average these data using the procedures specified in paragraph (a)(2)(ii) of this section, and use the average value in Equation C-8 | mmBtu per mass or volume | Table C-1 or calculated per §98.33(a)(2)(ii) |
EF | Fuel-specific default emission factor for CH4 or N2O, from Table C-2 of this subpart | kg CH4 or N2O per mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-8a: Annual CH4 or N2O Emissions from the Combustion of Natural Gas - Therms
Equation C-8a calculates the annual CH4 or N2O emissions from the combustion of natural gas when natural gas consumption in billing records is expressed in therms.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of natural gas | metric tons | Output |
Fuel | Annual natural gas usage, from gas billing records | therms | User input |
EF | Fuel-specific default emission factor for CH4 or N2O, from Table C-2 of this subpart | kg CH4 or N2O per mmBtu | |
0.1 | Conversion factor from therms to mmBtu | - | 0.1 |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-8b: Annual CH4 or N2O Emissions from the Combustion of Natural Gas - mmBtu
Equation C-8b calculates the annual CH4 or N2O emissions from the combustion of natural gas when natural gas consumption in billing records is expressed in mmBtu.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of natural gas | metric tons | Output |
Fuel | Annual natural gas usage, from gas billing records | mmBtu | User input |
EF | Fuel-specific default emission factor for CH4 or N2O, from Table C-2 of this subpart | kg CH4 or N2O per mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-9a: Annual CH4 or N2O Emissions from the Combustion of a Particular Type of Fuel for which Tier 2 Is Used to Calculate CO2 Emissions
Equation C-9a calculates annual CH4 or N2O emissions from the combustion of a particular type of fuel for which Tier 2 is used to calculate CO2 emissions.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of a particular type of fuel | metric tons | Output |
Fuel | Mass or volume of the fuel combusted during the reporting year | short tons for solid fuel volume in standard cubic feet for gaseous fuel volume in gallons for liquid fuel | User input |
HHV | High heat value of the fuel, averaged for all valid measurements for the reporting year | mmBtu per mass or volume | User input |
EF | Fuel-specific default emission factor for CH4 or N2O, from Table C-2 of this subpart | kg CH4 or N2O per mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-9b: Annual CH4 or N2O emissions from the combustion of a solid fuel for which Equation C-2b Is Used to Calculate CO2 Emissions
Equation C-9b calculates annual CH4 or N2O emissions from the combustion of a solid fuel for which Equation C-2b Is Used to Calculate CO2 Emissions.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of a solid fuel | metric tons | Output |
Steam | Total mass of steam generated by solid fuel combustion during the reporting year | lb steam | User input |
B | Ratio of the boiler's maximum rated heat input capacity to its design rated steam output | mmBtu/lb steam | User input |
EF | Fuel-specific emission factor for CH4 or N2O, from Table C-2 of this subpart | kg CH4 or N2O per mmBtu | |
1 × 10−3 | Conversion factor from kilograms to metric tons | - | 0.001 |
Equation C-10: Annual CH4 or N2O Emissions from the Combustion of a Particular Type of Fuel for which Tier 4 Is Used to Calculate CO2 Emissions
Equation C-10 calculates annual CH4 or N2O emissions from the combustion of a particular type of fuel for which Tier 4 is used to calculate CO2 emissions.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
CH4 or N2O | Annual CH4 or N2O emissions from the combustion of a particular type of fuel | metric tons |
|
(HI)A | Cumulative annual heat input from combustion of the fuel | mmBtu |
|
EF | Fuel-specific emission factor for CH4 or N2O, from Table C-2 of this section | kg CH4 or N2O per mmBtu) |
|
0.001 | Conversion factor from kg to metric tons | - |
|
Equation C-13: Annual Volume of CO2 Emitted from Combustion of a Particular Fossil Fuel
Equation C-13 calculates annual volume of CO2 emitted from combustion of a particular fossil fuel.
The table below defines the parameters in this equation and provides the values or sources of any constants, default values, and lookup values.
Parameter | Description | Units of Measure | Value or Source |
|---|---|---|---|
Vff | Annual volume of CO2 emitted from combustion of a particular fossil fuel | scf | Output |
Fuel | Total quantity of the fossil fuel combusted in the reporting year, from company records, as defined in §98.6 | lb for solid fuel gallons for liquid fuel scf for gaseous fuel | User input |
Fc | Fuel-specific carbon based F-factor, either a default value from Table 1 in section 3.3.5 of appendix F to 40 CFR part 75, or a site-specific value determined under section 3.3.6 of appendix F to 40 CFR part 75 | scf CO2/mmBtu | Table 1 in Appendix F in 40 CFR 75 or |
HHV | Annual average high heat value of the fossil fuel, from fuel sampling and analysis (Sampled as specified (e.g., monthly, quarterly, semi-annually, or by lot in §98.34(a)(2). The average HHV shall be calculated according to the requirements of paragraph (a)(2)(ii) of this section.) | Btu/lb for solid fuel Btu/gal for liquid fuel Btu/scf for gaseous fuel | User input
|
106 | Conversion factor, Btu per mmBtu | - | 1000000 |