NOx Emissions Reductions from Implementation of the 2000 IECC/IRC Conservation Code to Residential Construction in Texas

Abstract

Four areas in Texas have been designated by the United States Environmental Protection Agency (EPA) as non-attainment areas because ozone levels exceed the National Ambient Air Quality Standard (NAAQS) maximum allowable limits. These areas face severe sanctions if attainment is not reached by 2007. Four additional areas in the state are also approaching national ozone limits (i.e., classified as affected areas). In 2001, the Texas State Legislature formulated and passed the Texas Emissions Reduction Plan (TERP), to reduce ozone levels by encouraging the reduction of emissions of NOx by sources that are currently not regulated by the state. An important part of this legislation is the State's energy efficiency program, which includes reductions in energy use and demand that are associated with the adoption of the 2000 IECC1, which represents one of the first times that the EPA is considering emissions reductions credits from energy conservation - an important new development for building efficiency professionals. This paper provides an overview of the procedures that have been developed and used to calculate the electricity savings and NOx reductions from residential construction in nonattainment and affected counties2. Results are presented that show the annual electricity and natural gas savings and NOx reductions from implementation of the 2000 IECC to singlefamily and multi-family residences in 2003, which use a code-traceable DOE-2 simulation. A second paper provides a detailed discussion of the methods used to calculate the emissions 1 This includes the 2001 Supplement to the 2000 IECC and 2000 IRC (IRC 2000, IECC 2001). 2 The procedures outlined in this paper were developed and used in the Laboratory's 2002 and 2003 Annual Report to the TCEQ to satisfy the requirements of the Senate Bill 5 Legislation. In 2003 the Laboratory was awarded a grant from the EPA, which is administered through the TCEQ, to expand the development of these procedures into a webbased tool that would provide state and local authorities with accurate emissions reductions for use in preparing State Implementation Plans. reductions using the eGRID database (Haberl et al. 2004).