William Healy

Dr. William M. Healy is the Chief of the Building Energy and Environment Division of the Engineering Laboratory at the National Institute of Standards and Technology (NIST). In this role, Dr. Healy oversees a staff that conducts research to enable cost-effective, energy-efficient, grid-integrated buildings that have healthy and comfortable indoor environments and reduced environmental impacts through advances in measurement science and standards development.

Dr. Healy joined NIST in March 1999 and assumed the duties of Group Leader of the Heat Transfer and Alternative Energy Systems Group in 2007. His research interests involve the development of improved test methods and metrics for rating the performance of residential water heating systems and evaluation of the performance of net-zero energy homes. Dr. Healy has also investigated improved sensing methods for determining the moisture content within building envelopes. As a result of this effort, he and his collaborators were awarded a patent on the use of ultra-wideband radar to map the moisture state of a wall. Additional efforts have included support of the guarded hot plate development through finite element modeling and participation in efforts by the Department of Homeland Security to develop the infrastructure to allow for data from sensors to be propagated to applications that require knowledge of hazard levels.  For his work as part of several NIST teams, Dr. Healy received a Department of Commerce Silver Medal (2009), a Department of Commerce Energy and Environmental Stewardship Award (2013), and the NIST Jacob Rabinow Applied Research Award (2016).

Dr. Healy is a member of the American Society of Mechanical Engineers (ASME) and the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). In ASHRAE, he currently serves as Chair of the Residential Buildings Committee and is a past chair of Technical Committee (TC) 6.6: Service Water Heating Systems.  He has served as a voting member on ASHRAE TC 7.5: Smart Building Systems, ASHRAE TC 4.4: Building Materials and Building Envelope Performance, ASHRAE SPC 118.2: Method of Test for Rating Residential Water Heaters, and ASHRAE SPC 146: Method of Test for Rating Pool Heaters.  

Dr. Healy currently teaches Thermal Systems Design and Analysis & Energy and Environment in the Engineering for Professionals program.  He has previously taught Applied Heat Transfer, Heat Transfer, and Computer Applications Software. 

Education History

• Bachelor of Science, Mechanical Engineering, Cornell University
• M.S., Mechanical Engineering, Georgia Institute of Technology
• Doctor of Philosophy, Mechanical Engineering, Georgia Institute of Technology

Work Experience

Division Chief, National Institute of Standards and Technology

Publications

Journal Publications

Healy, W.M., Cetin, K., Karg, R., Sekhar, C., Song, L., Sowa, J., Walker, I., Wargocki, P. “Working from Home and the Impacts on Residential Buildings” to appear in ASHRAE Journal, January 2024.

Logan-Jackson, A. R., Duarte Batista, M., Whelton, A., Bartrand, T., Healy, W., Ullah, T., Proctor, C. (2023). A Critical Review on the Factors that Influence Opportunistic Premise Plumbing Pathogens: From Building Entry to Fixture in Residences. Environmental Science and Technology. https://pubs.acs.org/doi/10.1021/acs.est.2c04277

Healy, W.M., Hiller, C.C., Lutz, J. “How Residential Water Heating is Changing” ASHRAE Journal, March 2021.

Feldhofer, M., Healy, W.M., “Improving the Energy Flexibility of Single-Family Homes through Adjustments to Envelope and Heat Pump Parameters” J. Building Engineering 39: 102245. February 2021. 10.1016/j.jobe.2021.102245.

Healy, W.M., Fanney, A.H., Dougherty, B.P., Ng, L., Payne, V., Ullah, T., Omar, F. “Performance Data from the NIST Net-Zero Energy Residential Test Facility” J. Res. National Institute of Standards and Technology 122, No. 14. January 2017. https://doi.org/106028/jres.122.014.

Fanney, A.H., Healy W.M., Payne, V., Kneifel, J., Ng, L., Dougherty, B., Ullah, T., Omar, F. “Small Changes Yield Large Results at NIST’s Net-Zero Energy Residential Test Facility” J. Solar Energy Engineering 139, No. 6. September 2017. http://dx.doi.org/10.1115.1.4037815

Healy, W.M. “The Dependence of Water Heater Energy Factor on Deviations from Nominal Test Conditions” ASHRAE Transactions 123, No. 2, pp. 110-125, June 2017.

Healy, W.M., Fanney, A.H., Dougherty, B.P., Ng, L.C., Payne, W.V., Ullah, T., Omar, F. Performance Data from the NIST Net-Zero Energy Residential Test Facility, J. Research National Institute of Standards and Technology 122, January 17, 2017. https://dx.doi.org/10.6028/jres.122.014

Balke, E.C., Healy, W.M., Ullah, T. “An Assessment of Efficient Water Heating Options for an All-Electric Single Family Residence in a Mixed Humid Climate” Energy and Buildings 133, pp. 371-380, December 2016.

Fanney, A.H., V. Payne, T. Ullah, L. Ng, M. Boyd, F. Omar, M. Davis, H. Skye, B. Dougherty, B. Polidoro, W. Healy, J. Kneifel, B. Pettit. “Net-zero and beyond! Design and performance of NIST’s net-zero energy residential test facility” Energy and Buildings 101, pp. 95-109, August 2015.

Kneifel, J., W. Healy, J. Filliben, M. Boyd. “Energy performance sensitivity of a net-zero energy homoe to design and use specifications” J. Building Performance Simulation, pp. 1-14, February 2, 2015.

Guo, W., Healy, W.M., Zhou, M. “Power Supply Issues for Wireless Sensor Networks: A Review” International Journal of Intelligent Control and Systems 19:1, pp. 15-23, March 2014.

Guo, W., Healy, W.M., Zhou, M. “Impacts of 2.4 GHz ISM Band Interference on IEEE 802.15.4 Wireless Sensor Network Reliability in Buildings” IEEE Transactions on Instrumentation and Measurement 61:9, pp. 2533-2544, September 2012.

Healy, W.M., Ullah, T., Roller, J.F. “Input-Output Approach to Predicting the Energy Efficiency of Residential Water Heaters – Testing of Gas Tankless and Electric Storage Water Heaters” ASHRAE Transactions 117:2, pp. 521-532, November 2011.

Jang, W.S., Healy, W.M. “Wireless Sensor Network Performance Metrics for Building Applications” Energy & Buildings 42: 6, pp. 862-868, June 2010.

Jang, W.S., Healy, W.M., Skibniewski, M.J. “Wireless Sensor Networks as Part of a Web-Based Building Environmental Monitoring System” Automation in Construction 17:6, pp. 729-736, August 2008.

Healy, W.M. 2008. Effect of Temperature Stratification Near Heating Elements on the Measured Energy Factors of Electric Water Heaters. ASHRAE Transactions 114 (2): 85-95.

Hutzel, William J. & William M. Healy. “Remotely Accessed Photovoltaic Power Experiment” Journal of Engineering Technology 23:1, pp. 32-39, Spring 2006

Healy, W.M. 2005, “Lessons Learned in Wireless Monitoring,” ASHRAE Journal, Vol. 47 No 10, October 2005, pp. 54-60.

Healy, W.M. & van Doorn, E. 2004. A Preliminary Investigation on the Use of Ultra-Wideband Radar for Moisture Detection in Building Envelopes. ASHRAE Transactions Vol. 111.
Healy, W.M., J.D. Lutz, and A.B. Lekov, “Variability in Energy Factor Test Results for Residential Electric Water Heaters,” HVAC&R Research Journal 9:4, pp. 435-449, October 2003.
Healy, W.M., “Moisture Sensor Technology: A Summary of Techniques for Measuring Moisture Levels in Building Envelopes,” ASHRAE Transactions: 2003 Winter Meeting, 2003.

Healy, W.M., J.G. Hartley, and S.I. Abdel-Khalik, “On the validity of the adiabatic spreading assumption in droplet impact cooling,” Int. J. Heat Mass Transfer 44, 3869-3881, 2001.

Healy, W.M., J.G. Hartley, and S.I. Abdel-Khalik, “Surface wetting effects on the spreading of liquid droplets impacting a solid surface at low Weber numbers,” Int. J Heat Mass Transfer 44, 235-240, 2001.

Healy, W.M., P.J. Halvorson, J.G. Hartley, and S.I. Abdel-Khalik, “A critical heat flux correlation for droplet impact cooling at low Weber numbers and various ambient pressures,” Int. J. Heat Mass Transfer 41, 975-978, 1998.

Healy, W.M., J.G. Hartley, and S.I. Abdel-Khalik, “Comparison between theoretical models and experimental data for the spreading of liquid droplets impacting a solid surface,” Int. J. Heat Mass Transfer 39, 3079-3082, 1996.

Conference Publications

Healy, W.M. and Guo, W., “Net-Zero Homes – It’s About More than Energy: A Case Study of Power Performance” Proc of ACEEE Summer Study on Energy Efficiency in Buildings, Asilomar, CA, August 2018.

Ullah, T., Fanney, A.H., Healy, W.M., Poppendieck, D, Teichman, K. “Energy and Indoor Air Quality Benchmarking of the NIST Net-Zero Energy Residential Test Facility (NZERTF)” Proc. of 2016 ACEEE Summer Study on Energy Efficiency in Buildings, August 2016.

Ullah, T., Healy, W.M. “The Performance of an Auxiliary Heat Pump Water Heater Installed in a Dual-Tank System in a Net Zero Energy Residence” Proceedings of the 2016 ASHRAE Winter Conference. Orlando, FL, January 2016.

Ullah, T., Healy, W.M. “The Effect of Piping Heat Losses on the Efficiency of Solar Thermal Water Heating in a Net-Zero Energy Home” Proceedings of the 2015 ASHRAE Winter Conference. Chicago, IL, January 2015.

Guo, W., Healy, W.M., Zhou, M. “Experimental Study of the Thermal Impacts on Wireless Sensor Batteries” Proceedings of the 2013 IEEE International Conference on Networking, Sensing, and Control. April 2013.

Guo, W., Healy, W.M., Zhou, M. “Battery Discharge Characteristics of Wireless Sensors in Building Applications” ICNSC12: 9th International Conference on Networking, Sensing, and Control. April 2012.

Guo, W., Healy, W.M., Zhou, M. “Interference Impacts on ZigBee-based Wireless Mesh Networks for Building Automation and Control” Proceedings of the 2011 IEEE International Conference on Systems, Man, and Cybernetics. September 2011.

Guo, W., Healy, W.M., Zhou, M. “Performance Measurements and Analysis of Low Data Rate Wireless Communication Under Interference Sources in Buildings” Proceedings of the 2010 International Conference on Systems, Man, and Cybernetics, October 2010.

Guo, W., Healy, W.M., Zhou, M. “An Experimental Study of Interference Impacts on ZigBee-based Wireless Communications Inside Buildings” Proceedings of the 2010 IEEE Conference on Mechatronics and Automation, August 2010.

Guo, W., Healy, W.M., Zhou, M. “ZigBee-Wireless Mesh Networks for Building Automation and Control” Proceedings of the 2010 IEEE International Conference on Networking, Sensing, and Control, April 2010.

Jang, W.S., Healy, W.M. “Assessment of Performance Metrics for Use of Wireless Sensor Networks in Buildings” Proceedings of The International Symposium on Automation and Robotics in Construction (ISARC 2009), September 2009.

Healy, W.M. “In-situ measurement of the moisture content of building materials using ultra-wideband radio waves”, Proceedings of 3rd International Building Physics/Science Conference, August 2006.

Flynn, D.R., W.M. Healy, and R.R. Zarr, “High-Temperature Guarded Hot Plate Apparatus: Optimal Locations of Circular Heaters.” Thermal Conductivity 28/Thermal Expansion 16. 2005.

Flynn, D.R., W.M. Healy, and R.R. Zarr, “High-Temperature Guarded Hot Plate Apparatus – Control of Edge Heat Loss.” Thermal Conductivity 28/Thermal Expansion 16. 2005.

Zarr, R.R., D.R. Flynn, J.W. Hettenhouser, N.J. Brandenburg, and W.M. Healy, “Fabrication of a Guarded-Hot-Plate Apparatus for Use Over an Extended Temperature Range and in a Controlled Gas Atmosphere.” Thermal Conductivity 28/Thermal Expansion 16. 2005.

Healy, W.M. & van Doorn, E. 2004. Detection of Moisture Accumulation in Wall Assemblies Using Ultra-Wideband Radio Signals. Thermal Performance of the Exterior Envelopes of Buildings IX. Conference Proceedings, Clearwater Beach, FL, December 5-10, 2004.

W.M. Healy, S. Luo, M. Evans, A. Sucheta, and Y. Liu, “Development of an Optical Fiber-Based Moisture Sensor for Building Envelopes,” Proceedings of the 24th AIVC Conference and BETEC Conference: Ventilation, Humidity Control, and Energy, pp. 277-282, 2003.

W.M. Healy and D.R. Flynn, “Thermal Modeling of Multiple-Line-Heat-Source Guarded Hot Plate Apparatus,” Insulation Materials: Testing and Applications: 4th Volume, ASTM STP 1426, A.O. Desjarlais and R.R. Zarr, Eds., ASTM International, West Conshohocken, PA, pp. 79-97, 2002.

D.R. Flynn, R.R. Zarr, M.H. Hahn, and W.M. Healy, “Design Concepts for a New Guarded Hot Plate Apparatus for Use Over an Extended Temperature Range,” Insulation Materials: Testing and Applications: 4th Volume, ASTM STP 1426, A.O. Desjarlais and R.R. Zarr, Eds., ASTM International, West Conshohocken, PA, pp. 98-115, 2002.

W.M. Healy, “Using Finite Element Analysis to Design a New Guarded Hot Plate Apparatus for Measuring the Thermal Conductivity of Insulating Materials,” Proc. ANSYS/Mallett Users’ Conference, College Park, MD, October 2001.

Other

Persily, A.K., Duarte Batista, M., Healy, W.M., Kedzierski, M.A., Lin, L., Milesi Ferrett, N.S., Ullah, T., Yashar, D., Zimmerman, S. “November 2022 NIST Premise Plumbing Research Workshop: Summary and Findings” NIST Technical Note 2256, July 2023. 10.6028/NIST.TN.2256.

Evans, H., Greene, K, Healy, W., Hoffman, E., Rimmer, C., Sberegaeva, A., Zimmerman, N. “National Institute of Standards and Technology Environmental Scan 2020” NIST Interagency/Internal Report 8348, February 2021. 10.6028/NIST.IR.8348.

Persily, A.K., Yashar, D.A. , Milesi-Ferretti, N.S., Ullah, T., Healy, W.M. Measurement Science Research Needs for Premise Plumbing Systems” NIST Technical Note 2088, May 2020. https://doi.org/10.6028/NIST.TN.2088

Healy, W., Kneifel, J., O’Rear, E. “Economics of the Net-Zero Energy Residential Test Facility,” Energy Design Update 38, No. 1, January 2018.

Healy, W., Ng, L., Poppendieck, D. “Indoor Air Quality and Ventilation in the NIST Net-Zero Energy Residential Test Facility” Energy Design Update 37, No. 4, July 2017.

Healy, W.M., Dougherty, B.P. “The NIST Net-Zero Energy Residential Test Facility – Equipment Performance,” Energy Design Update 37, No. 1, January-February 2017.

Healy, W.M. “Lessons Learned from a Year at the NIST Net-Zero Energy Residential Test Facility,” Energy Design Update 36, No. 9, pp. 1-6, September 2016.

Domich, P.D., Pettit, B., Fanney, A.H., Healy, W.M. “Research and Development Opportunities for the NIST Net Zero Energy Residential Test Facility” NIST Technical Note 1869, March 2015.

Davis, M, W. Healy, M. Boyd, L. Ng, V. Payne, H. Skye, T. Ullah. “Monitoring Techniques for the Net-Zero Energy Residential Test Facility” NIST Technical Note 1854, December 2014.

Pettit, B., C. Gates, H. Fanney, W. Healy. “Design Challenges of the NIST Net Zero Energy Residential Test Facility” NIST Technical Note 1847, September 2014.

Pellegrino, J, Fanney, A.H, Persily, A.K, Domanski, P.A., Healy, W.M., and Bushby, S.T. “Measurement Science Roadmap for Net-Zero Energy Buildings” NIST Technical Note 1660, March 2010.

Healy, W.M. “Measurement Challenges in Achieving Energy Monitoring Systems in Buildings” NIST Technical Note 1656, March 2010.

Healy, W.M. and Jang, W.S. “Practical Challenges in Wireless Sensor Network Use in Buildings” NIST Technical Note 1604, September 2008.

Honors and Awards

• Best Instructor Award, Johns Hopkins University Engineering for Professionals Program (2022)
• ASHRAE Distinguished Service Award (2019)
• NIST Jacob Rabinow Applied Research Award (2016)
• Department of Commerce Energy and Environmental Stewardship Award (2013)
• ASHRAE Best Paper Award (2012)
• Department of Commerce Silver Medal (2009)

Professional Organizations

American Society of Mechanical Engineers
American Society of Heating, Refrigerating, and Air-Conditioning Engineers