%0 Journal Article
%A Richard C Diamond
%A Craig P Wray
%A Darryl J Dickerhoff
%A Nance Matson
%A Duo Wang
%D 2003
%G eng
%T Thermal distribution systems in commercial buildings
%1 <p>1.4</p>
%2 LBNL-51860
%X <p>Previous research suggests that HVAC thermal distribution systems in commercial buildings suffer from  thermal losses, such as those caused by duct air leakage and poor duct location. Due to a lack of metrics  and data showing the potentially large energy savings from reducing these losses, the California building  industry has mostly overlooked energy efficiency improvements in this area. The purpose of this project is  to obtain the technical knowledge needed to properly measure and understand the energy efficiency of  these systems. This project has three specific objectives: to develop metrics and diagnostics for determining  system efficiencies, to develop design and retrofit information that the building industry can use to improve  these systems, and to determine the energy impacts associated with duct leakage airflows in an existing  large commercial building. The primary outcome of this project is the confirmation that duct leakage  airflows can significantly impact energy use in large commercial buildings: our measurements indicate that  adding 15% duct leakage at operating conditions leads to an increase in fan power of about 25 to 35%. This  finding is consistent with impacts of increased duct leakage airflows on fan power that have been predicted  by previous simulations. Other project outcomes include the definition of a new metric for distribution  system efficiency, the demonstration of a reliable test for determining duct leakage airflows, and the  development of new techniques for duct sealing. We expect that the project outcomes will lead to new  requirements for commercial thermal distribution system efficiency in future revisions of California's Title  24.</p>