%0 Report
%A Max H Sherman
%A Nance Matson
%D 2002
%G eng
%T Air Tightness of New U.S. Houses: A Preliminary Report
%1 2.3
%2 LBNL-48671
%X Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e.,  infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of  envelope air-tightness is critical to determining how much energy is being lost through infiltration and how  much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a  blower door. Tens of thousands of unique fan pressurization measurements have been made of U.S.  dwellings over the past decades. LBNL has collected the available data on residential infiltration into its  Residential Diagnostics Database, with support from the U.S. Department of Energy. This report  documents the envelope air leakage section of the LBNL database, with particular emphasis on new  construction. The work reported here is an update of similar efforts carried out a decade ago, which used available data  largely focused on the housing stock, rather than on new construction. The current effort emphasizes shell  tightness measurements made on houses soon after they are built. These newer data come from over two  dozen datasets, including over 73,000 measurements spread throughout a majority of the U.S. Roughly  one-third of the measurements are for houses identified as energy-efficient through participation in a  government or utility program. As a result, the characteristics reported here provide a quantitative estimate  of the impact that energy-efficiency programs have on envelope tightness in the US, as well as on trends in  construction.