Record Display for the EPA National Library Catalog

RECORD NUMBER: 2 OF 2

OLS Field Name OLS Field Data
Main Title Calculation of Age Distributions in the Nonroad Model: Growth and Scrappage.
CORP Author Environmental Protection Agency, Washington, DC. Air and Radiation Div.
Publisher Apr 2004
Year Published 2004
Report Number EPA/420/P-04/007;
Stock Number PB2005-106073
Additional Subjects Population growth ; Scrappage curve ; Calculations ; Nonroad equipment populations ; NONROAD2004 emission inventory model ; Equipment age distributions ; Environmental Protection Agency
Internet Access
Description Access URL
http://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P10001VM.PDF
Holdings
Library Call Number Additional Info Location Last
Modified
Checkout
Status
NTIS  PB2005-106073 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. 07/12/2006
Collation 20p
Abstract
EPA's draft NONROAD2004 emission inventory model calculates nonroad equipment populations by age (i.e., an age distribution) for given equipment types and scenario years. This calculation is necessary for the model to account for factors which affect nonroad emissions over time as the in-use fleet ages and turns over to newer equipment, including emissions deterioration, new emissions standards, technology changes, and changes in equipment population resulting from sales growth trends. The NONROAD model calculates equipment age distributions for each horsepower range of each equipment type based on the median life (hours at full load), activity (hours of use per year), load factor, and current growth rate for that equipment, combined with the model's generalized scrappage function. Age distribution refers to the fractions of a given equipment's population that are one, two, three, etc., years old in a given target year. This age distribution is treated as constant regardless of the target calendar year being evaluated, as described in more detail below. This methodology differs from the previous versions of NONROAD, which attempted to calculate age distributions for future years by stepping through each year between the base year and future evaluation year, calculating equipment populations and scrappage for each model year of equipment still in service, and the necessary equipment sales to meet the projected population.