Evaluation of Pollutant Emissions from Portable Air Cleaners Final Report: Contract No. 10-320 Prepared for the California Air Resources Board and the California Environmental Protection Agency Research Division PO Box 2815 Sacramento CA 95812 Prepared by: Hugo Destaillats (principal investigator), Mohamad Sleiman and William J. Fisk Indoor Environment Group Energy Analysis and Environmental Impacts Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley, CA 94720 December 2014 Emissions from Portable Air Cleaners Final Report Disclaimer The statements and conclusions in this Report are those of the contractor and not necessarily those of the California Air Resources Board. The mention of commercial products, their source, or their use in connection with material reported herein is not to be construed as actual or implied endorsement of such products. ii Emissions from Portable Air Cleaners Final Report Table of Contents List of Figures................................................................................................................ vii List of Tables ................................................................................................................... x Abstract ........................................................................................................................ xii Executive Summary ...................................................................................................... xiii Background ........................................................................................................................... xiii Methods ................................................................................................................................ xiii Results .................................................................................................................................. xiv Conclusions ........................................................................................................................... xv 1. INTRODUCTION ........................................................................................................ 1 1.1. Technologies considered in this study ........................................................................ 2 1.2. Goals and scope of this study .................................................................................... 5 MATERIALS AND METHODS ........................................................................................ 8 2. SELECTION AND PROCUREMENT OF AIR CLEANERS USED IN THIS STUDY ............ 9 3. DEVELOPMENT OF A TESTING PROTOCOL FOR PORTABLE AIR CLEANERS ......... 12 3.1. Room-Sized Experimental Chamber ........................................................................ 12 3.2. Challenge pollutant mixture ..................................................................................... 14 3.3. Analytical methods for VOCs and aldehydes ............................................................. 15 3.4. Ozone Measurements and Ozone Chamber Deposition Rates ................................... 16 3.5. Ultrafine Particle Measurements .............................................................................. 18 3.6. Analysis of Reactive Oxygen Species (ROS) ............................................................ 21 3.6.1. Determination of ROS concentrations .................................................................... 22 3.7. Preliminary Tests ................................................................................................... 26 RESULTS AND DISCUSSION ...................................................................................... 28 4. EXPERIMENTAL CHARACTERIZATION OF EMISSIONS FROM AIR CLEANERS ........ 29 4.1. PAC1: PCO Air Cleaner .......................................................................................... 29 4.1.1. Summary of observations ..................................................................................... 29 4.1.2. Ozone ................................................................................................................ 29 4.1.3. VOCs ................................................................................................................. 31 4.1.4. Ultrafine particles ................................................................................................. 33 iv Emissions from Portable Air Cleaners Final Report 4.2. PAC2: Air Cleaner Combining HEPA / PCO / Catalyst ............................................... 35 4.2.1. Summary of observations ..................................................................................... 35 4.2.2. Ozone ................................................................................................................ 35 4.2.3. VOCs ................................................................................................................. 37 4.2.4. Ultrafine particles ................................................................................................. 39 4.3. PAC3: PCO Air Cleaner with Ozone Generation ........................................................ 41 4.3.1. Summary of observations ..................................................................................... 41 4.3.2. Ozone ................................................................................................................ 41 4.3.3. VOCs ................................................................................................................. 43 4.3.4. Ultrafine particles ................................................................................................. 45 4.4. PAC4: Plasma Air Cleaner ...................................................................................... 47 4.4.1. Summary of observations ..................................................................................... 47 4.4.2. Ozone ................................................................................................................ 47 4.4.3. VOCs ................................................................................................................. 49 4.4.4. Ultrafine particles ................................................................................................. 51 4.5. PAC5: Ceramic Heater with Ionizer .......................................................................... 53 4.5.1. Summary of observations ..................................................................................... 53 4.5.2. Ozone ................................................................................................................ 56 4.5.3. VOCs ................................................................................................................. 58 4.5.4. Ultrafine particles ................................................................................................. 61 4.6. PAC6: Heating Air Purifier ....................................................................................... 63 4.6.1. Summary of observations ..................................................................................... 63 4.6.2. Ozone ................................................................................................................ 63 4.6.3. VOCs ................................................................................................................. 65 4.6.4. Ultrafine particles ................................................................................................. 67 4.7. ROS measurements ............................................................................................... 69 5. EVALUATION OF THE IMPACTS OF AIR CLEANERS ON INDOOR AIR QUALITY ....... 73 5.1. Determination of air flow in each device .................................................................... 73 5.2. Net Direct (Primary) Pollutant Emissions (Phase 1) ................................................... 75 5.3. Net Pollutant Emissions or Removal in the Presence of Challenge Mixture (Phase 2) ... 80 5.3.1. Pollutant emission and removal rates in Phase 2 .................................................... 80 5.3.2. Yields of Byproducts Generated in the Air Cleaning Process ................................... 84 5.3.3. Evaluation of VOC removal effectiveness .............................................................. 85 5.4. Predicted Impacts on Typical Indoor Scenarios ......................................................... 91 5.4.1. Indoor Pollutant Levels Predicted through a Material-Balance Model ........................ 91 5.4.2. Potential Health Implications ................................................................................. 98 v Emissions from Portable Air Cleaners Final Report 6. SUMMARY, CONCLUSIONS AND RECOMMENDATIONS ........................................ 102 References ................................................................................................................ 104 List of Publications Generated by this Study .................................................................. 112 Glossary of Terms, Abbreviations and Symbols ............................................................. 113 APPENDICES ............................................................................................................ 115 APPENDIX 1. DEVELOPMENT OF SAMPLING AND ANALYTICAL METHODS FOR THE QUANTIFICATION OF ROS ........................................................................................ 116 A.1.1.