Ventilation System Effectiveness and Tested Indoor Air Quality Impacts Armin Rudd and Daniel Bergey Building Science Corporation February 2014 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, subcontractors, or affiliated partners makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. Available electronically at http://www.osti.gov/bridge Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from: U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 phone: 865.576.8401 fax: 865.576.5728 email: mailto:[email protected] Available for sale to the public, in paper, from: U.S. Department of Commerce National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 phone: 800.553.6847 fax: 703.605.6900 email: [email protected] online ordering: http://www.ntis.gov/ordering.htm Printed on paper containing at least 50% wastepaper, including 20% postconsumer waste Ventilation System Effectiveness and Tested Indoor Air Quality Impacts Prepared for: The National Renewable Energy Laboratory On behalf of the U.S. Department of Energy’s Building America Program Office of Energy Efficiency and Renewable Energy 15013 Denver West Parkway Golden, CO 80401 NREL Contract No. DE-AC36-08GO28308 Prepared by: Armin Rudd and Daniel Bergey Building Science Corporation 30 Forest Street Somerville, MA 02143 NREL Technical Monitor: Cheryn Metzger Prepared under Subcontract No. KNDJ-0-40337-03 February 2014 iii [This page left blank] iv Contents List of Figures ..........................................................................................................................vi List of Tables .......................................................................................................................... viii Definitions ................................................................................................................................ix Acknowledgments ....................................................................................................................x Executive Summary ................................................................................................................. xi 1 Problem Statement ..............................................................................................................1 1.1 Introduction ...................................................................................................................................... 1 1.2 Background ...................................................................................................................................... 1 1.2.1 Research Questions ............................................................................................................. 3 1.3 Relevance to Building America’s Goals .......................................................................................... 3 1.4 Cost Effectiveness ............................................................................................................................ 4 1.5 Tradeoffs and Other Benefits ........................................................................................................... 8 2 Previous Research ..............................................................................................................9 3 Test and Analysis Method ................................................................................................ 10 3.1 Description of the Test Houses ...................................................................................................... 10 3.2 HVAC System Modifications and Pretesting ................................................................................ 13 3.3 Testing Approach ........................................................................................................................... 15 3.3.1 Baseline Test ..................................................................................................................... 18 3.3.2 Exhaust Test ...................................................................................................................... 18 3.3.3 Exhaust With Mixing Test ................................................................................................ 18 3.3.4 Central Fan Integrated Supply Test .................................................................................. 19 3.3.5 Energy Recovery Ventilator Test ...................................................................................... 19 3.4 Building Enclosure, Central Air Distribution System, and Ventilation Systems Characterization 19 3.5 Per-Fluorocarbon Tracer Gas Testing ............................................................................................ 19 3.6 Airborne Particulate Sampling ....................................................................................................... 22 3.7 Volatile Organic Compound Sampling .......................................................................................... 24 3.8 Formaldehyde Sampling ................................................................................................................ 25 4 Discussion of Results ....................................................................................................... 26 4.1 Building Air Leakage Characterization ......................................................................................... 26 4.1.1 Fan Pressurization Tests ................................................................................................... 26 4.2 HVAC Characterization ................................................................................................................. 26 4.3 Per-Fluorocarbon Tracer Gas testing ............................................................................................. 29 4.3.1 Zone Air Change Rates ..................................................................................................... 29 4.3.2 Interzonal Airflows ........................................................................................................... 33 4.4 Airborne Particulate Sampling ....................................................................................................... 42 4.5 Formaldehyde Sampling ................................................................................................................ 53 4.6 Volatile Organic Compound Sampling .......................................................................................... 56 5 Summary of Results .......................................................................................................... 67 6 Author Recommendations ................................................................................................ 70 6.1 Relevant Issues With ASHRAE Standard 62.2 ............................................................................. 70 6.1.1 Source of Outside Air ....................................................................................................... 70 6.1.2 Ventilation Effectiveness .................................................................................................. 71 6.2 Recommendations for Ventilation Rates ....................................................................................... 72 References .............................................................................................................................. 76 Appendix A: Listing of All Top 20 Volatile Organic Compounds Found, and Their Functional Descriptions.................................................................................................... 78 Appendix B: Preliminary CONTAM Model ............................................................................. 82 v List of Figures Figure 1. Energy savings and costs: vented attic, 5% duct leakage ..................................................... 7 Figure 2. Energy savings and costs: vented attic, no duct leakage ...................................................... 7 Figure 3. Energy savings and costs: unvented attic, no duct leakage ................................................. 8 Figure 5. Location and directions to the test homes at University of Texas-Tyler ............................ 10 Figure 5. House 1 vented attic (left) and House 2 unvented attic (right) ............................................. 11 Figure 6. Exterior photos of the test homes at the UT-Tyler; House 1 has the darker roof ............. 11 Figure 7. Energy recovery ventilator (ERV) installed in House 1 to match that of House 2 ............. 12 Figure 9. Wye'd outside air duct, airflow stations, and inline fan for retrofitting a central fan integrated supply (CFIS)