EMISSION INVENTORY SOURCE CATEGORY

METHOD SUMMARY

This method is used to estimate the criteria pollutant emissions from the various types of residential wood combustion throughout the state. Estimates were made for 1991 for most areas of the state, and for 1993 using a revised methodology for the San Joaquin Valley Air Basin. Emissions are included for the types of devices that burn wood in a typical residence: fireplaces, wood burning stoves, and fireplace inserts. CES 82115 and 82123 are used for emission estimates made by ARB staff for all areas of the State. However, no annual emission estimation method has been derived for CES 47225, Residential Wood Combustion (Unspecified).

ACTIVITY DATA SOURCE:  For wood burning stoves and fireplace inserts (CES 82115), the energy demand of an average residence in each county was estimated using an equation cited from an American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., report "1989 ASHRAE Handbook Fundamentals I-P Edition." The equation uses the design heat loss for a house, the number of heating degree days for a designated area, and the heating value of the fuel used to estimate energy demand. A heating degree day is the number of degrees below 65 degrees F that an area experiences during a 24-hour day. For most areas in the state, It was obtained by averaging the heating degree day total from each county's weather station. For example, if a county has an average daily temperature of 40 degrees F, then the average degree day is 25. However, for the San Joaquin Valley Air Basin, the methodology was revised to take into account the small population residing near the weather stations at higher elevations. The data for weather stations above 1000 feet was excluded from the calculation for this reason. Emissions for the San Joaquin Valley Air Basin were estimated using the revised methodology for 1993. The number of residences burning wood for heating in each county was obtained from the 1990 U.S. census and grown to 1991.

The activity data for fireplaces (CES 82123) was derived from: "Analysis of Carbon Monoxide and Inhalable Particle Emissions from Woodburning Devices in Fresno, California," "Healdsburg Wood Heating Survey"and "The California Residential Wood Consumption Survey, Draft." The average wood consumption for fireplaces is estimated to be 0.28 cords per year and the number of wood burning households for each county is county dependant. To obtain the number of houses with active fireplaces, the wood burning household factor was multiplied by the total number of county housing units minus the number of households using wood stoves and fireplace inserts in each county. The amount of wood burned in fireplaces for each county was estimated by multiplying the number of houses with active fireplaces by the average amount of wood burned in a fireplace.

EMISSION FACTOR SOURCE:  The emissions were calculated using EPA's AP-42 emission factors for woodburning stoves and fireplaces. The factors account for the Phase I and Phase II woodburning stoves. The emission factors are summarized in Table I.

Table I

Emission Factors for Residential Woodburning Equipment (lb / ton)

TEMPORAL DATA:

DATE OF THE LAST UPDATE:  July 1993, San Joaquin Valley revision July 1997.

GROWTH PARAMETER:  Housing Units

STATEWIDE EMISSIONS SUMMARY (1991/1993(SJV) - ANNUAL AVERAGE TONS/DAY)

CES No.	TOG	CO	NOX	SOX	PM
82115	60.74	366.97	5.22	0.78	61.41
82123	61.59	499.18	5.14	0.79	68.38
Total	122.33	866.15	10.36	1.57	129.79

To download the complete methodology (48Kb) in Acrobat format, please click this icon;

Please send questions or comments to: eibweb@arb.ca.gov

This page last revised on November 12, 1997.

Area Source Top Page  |   Search ARB Programs/Topics  |   Email ARB Help Attendant