Chief Research Scientist
Chief Research Scientist

Biography

Dr. Timothy Salsbury joined Pacific Northwest National Laboratory (PNNL) in 2020, where he applies optimization and control theory to a broad range of challenges in electrical and mechanical systems. His work at PNNL has spanned topics from modeling viral fate and transport in buildings to co-optimizing power electronic-based generation, transmission, and distribution systems.

Dr. Salsbury is nationally and internationally recognized for advancing control theory, methods, and algorithms. His research has been applied to diverse systems, including power grids, chemical plants, refrigeration systems, and other demand-side energy applications. He holds 50 U.S. patents and has authored more than 75 publications in leading journals and conference proceedings. He is a senior member of IEEE. His pioneering contributions span three primary areas (1) Device-level control: Algorithms with low computational and storage overhead, typically operating at high frequencies; (2) System-level control and optimization: Architectures leveraging greater computational resources for slower, large-scale decision-making; and (3) Analytics and fault detection/diagnostics: Techniques for extracting actionable insights from data—both in real-time and offline.

Prior to joining PNNL, Dr. Salsbury held research leadership roles in corporate research and development at Johnson Controls (a Fortune 100 company), scientific appointments at Lawrence Berkeley National Laboratory, and Finland’s Technical Research Centre. He has a proven ability to translate fundamental research into practical impact and continues to do so at PNNL in support of sponsors, such as the Department of Energy and the Department of Defense.

Education

  • PhD in electromechanical and control engineering, Loughborough University
  • BEng in mechanical engineering (with honors), Loughborough University

Patents

Publications

2024

  • Faulkner C, Salsbury T, Abboushi B, Mouchref C, Singer B, Sohn M, and Arnold G. 2024. Comparison of Effectiveness and Energy Use of Airborne Pathogen Mitigation Measures to Meet Clean Air Targets in Office Buildings. Building and Environment 257. PNNL-SA-193005. doi:10.1016/j.buildenv. 2024.111466.
  • Hassanpour H, Hamedi A, Mhaskar P, House J, and Salsbury T. A Hybrid Clustering Approach Integrating First-Principles Knowledge with Data for Fault Detection in HVAC Systems. Computers & Chemical Engineering, Aug. 2024, LENSID: 086-085-884-006-040, doi:10.1016/j.compchemeng.2024.108717.
  • Yoder T, Pamintuan B, and Salsbury T. Building ControlScore: General Service Administration Office Building Deployment. Report. Jun. 28, 2024, LENSID: 127-938-824-026-194, doi:10.2172/2481967.
  • Faulkner C, Salsbury T, Abboushi B, Mouchref C, Singer B, Sohn M, Arnold G. Comparison of Effectiveness and Energy Use of Airborne Pathogen Mitigation Measures to Meet Clean Air Targets in a Prototypical Office Building. Building and Environment. Jun. 2024. LENSID: 004-235-606-803-468. doi:10.1016/j.buildenv.2024.111466.
  • Hassanpour H, Hamedi A, Mhaskar P, House J, Salsbury T. A Hybrid-based Clustering Approach for Fault Detection in HVAC Systems. IFAC-PapersOnLine, 2024, LENSID: 108-630-513-596-608, doi:10.1016/j.ifacol.2024.08.346.

2023

  • Daniel W, and Salsbury T. 2023. Verification and Validation for Energy System Co-Design and Simulation. Report. Apr. 01, 2023. Richland, WA: Pacific Northwest National Laboratory. LENSID: 084-858-262-825-016. doi:10.2172/2004970. PNNL-34506.
  • Salsbury T, Devaprasad K, Lutes R, and Rogers A. 2023. Smarter Building Start - A Distributed Solution. Energy and Buildings 282. PNNL-SA-177108. doi:10.1016/j.enbuild.2023.112776.
  • Yoder T., Salsbury T, Pamintuan B, and Pennell G. Improving A Probabilistic Approach to Assessing Building Performance. Zenodo (CERN European Organization for Nuclear Research). Oct. 09, 2023. LENSID: 026-128-675-643-247. doi:10.5281/zenodo.8421887.
  • Salsbury T, Terrill T, Goddard J, Yu M, Yoder T, and Duan X. A General Purpose Real-Time Optimization Strategy Applied to Minimizing Simultaneous Heating and Cooling in Buildings. 2023 American Control Conference (ACC). May 31, 2023. LENSID: 199-262-862-480-114. doi:10.23919/acc55779.2023.10156399.
  • Yoder T., Pamintuan B, and Salsbury T. Building ControlScore: Research Laboratory Building Deployment. Report. PNNL-34417. Richland, WA: Pacific Northwest National Laboratory. May 31, 2023. LENSID: 193-430-079-115-846. doi:10.2172/2482017.
  • Salsbury T, Rogers A, Yoder T, Johnson S, and Duan X. A New Control Score Concept for Building Performance Assessment. Journal of Building Engineering. May 2023. LENSID: 108-829-304-464-340. doi:10.1016/j.jobe.2022.105770.
  • Salsbury T, Devaprasad K, Lutes R, and Rogers A. Smarter Building Start – A Distributed Solution. Energy and Buildings. Mar. 2023. LENSID: 136-198-388-497-461. doi:10.1016/j.enbuild.2023.112776.
  • Naqvi S A R, Kar K, Bhattacharya S, Chandan V, Mishra S, and Salsbury T. Air Quality and Comfort Constrained Energy Efficient Operation of Multi-Zone Buildings. Jan. 01, 2023. LENSID: 065-378-364-673-525. doi:10.2139/ssrn.4404607.
  • Salsbury T, Devaprasad K, Lutes R, and Rogers A. Smarter Building Start-A Distributed Solution. Energy and Buildings. Volume 282, 1 March 2023, 112776.

2022

  • Zhao Z, Li Y, Salsbury T, and House J. Data-Driven Self-Optimizing Control with Parametric Programing Based Constraint Handling. Journal of Dynamic Systems, Measurement, and Control. Jul. 13, 2022. LENSID: 017-436-057-415-843. doi:10.1115/1.4054845
  • Pease L, Salsbury T, Anderson K, Underhill R, Flaherty J, Vlachokostas A, Burns C, Wang N, Kulkarni G, and James D. Size Dependent Infectivity of SARS-Cov-2 via Respiratory Droplets Spread Through Central Ventilation Systems. International Communications in Heat and Mass Transfer 132. PNNL-SA-161825. Mar. 2022. LENSID: 027-385-373-558-438. doi:10.1016/j.icheatmasstransfer.2021.105748.
  • Vlachokostas A, Burns C, Salsbury T, Daniel R, James D, Flaherty J, Wang N, Underhill R, Kulkarni G, and Pease L. Experimental Evaluation of Respiratory Droplet Spread to Rooms Connected by a Central Ventilation System. Indoor Air. Jan. 19, 2022. LENSID: 112-139-774-864-265. doi:10.1111/ina.12940. PMID: 35048430.
  • Abboushi B, Arnold G, Tuenge J, Salsbury T, DeGraw J, Nardell E. Energy Implications of Using Upper Room Germicidal Ultraviolet Radiation and HVAC Strategies to Combat SARS-CoV-2. Report. Aug. 2022.

2021

  • Pease L.F., N. Wang, T. Salsbury, R.M. Underhill, J.E. Flaherty, E. Vlachokostas, and G.R. Kulkarni, et al. 2021. Investigation of Potential Aerosol Transmission and Infectivity of SARS-CoV-2 through Central Ventilation Systems. Building and Environment 197. PNNL-SA-156558. Jan. 29, 2021. LENSID 018-133-217-350-11X. PMID 33531734. PMC 7844370. doi:10.1016/j.buildenv.2021.107633
  • Salsbury T. 2021. Smart Building Start (SBS) - CRADA 480. PNNL-SA-159222. Richland, WA: Pacific Northwest National Laboratory. Feb. 01, 2021. LENSID 150-239-918-934-100. doi:10.2172/1827794.
  • Zhao Z, Li Y, Salsbury T, and House J. Global Self-Optimizing Control with Data-Driven Optimal Selection of Controlled Variables with Application to Chiller Plant. Journal of Dynamic Systems, Measurement, and Control. Nov. 12, 2021. LENSID: 017-052-646-194-10X. doi:10.1115/1.4052395.
  • Dong L, Li Y, House J, and Salsbury T. Dither Extremum Seeking Control of a Variable Refrigerant Flow System with Equality Constraint Handling. Science and Technology for the Built Environment. Nov. 02, 2021. LENSID: 036-309-155-754-969. doi:10.1080/23744731.2021.1993671.
  • Zhao Z, Li Y, Salsbury T, and House J. (2021). Extremum-Seeking Control Integrated Online Input Selection with Application to a Chilled-Water Plant. Science and Technology for the Built Environment, 28(2), 170–187. doi: 10.1080/23744731.2021.1987140 

2020

  • Hassanpour H, Mhaskar P, House J, and Salsbury T. A Hybrid Modeling Approach Integrating First-Principles Knowledge with Statistical Methods for Fault Detection in HVAC Systems. Computers & Chemical Engineering. Nov. 2020. LENSID 021-347-957-168-219. doi:10.1016/j.compchemeng.2020.107022.
  • Dong L, Li Y, House J, and Salsbury T. Model-Free Control and Staging for Real-Time Energy Efficient Operation of a Variable Refrigerant Flow System with Multiple Outdoor Units. Applied Thermal Engineering. Nov. 2020. LENSID 031-140-593-849-340. doi:10.1016/j.applthermaleng.2020.115787.
  • Zhao Z, Salsbury T, House J, Alcala C, and Li Y. A Comparison of Two Extremum Seeking Control Strategies Based on Simulation and Laboratory Tests for Heat Pump Air Conditioning. Science and Technology for the Built Environment. Aug. 25, 2020. LENSID 056-986-070-831-762. doi:10.1080/23744731.2020.1806625.
  • Salsbury T, House J, and Alcala C. Self-Perturbing Extremum-Seeking Controller with Adaptive Gain. Control Engineering Practice. Aug. 2020. LENSID 176-481-034-023-191, doi:10.1016/j.conengprac.2020.104456.
  • Zhao Z, Li Y, Salsbury T, House J, and Alcala C. Local Self-Optimizing Control Based on Extremum Seeking Control. Control Engineering Practice. Jun. 2020. LENSID 106-464-371-746-004. doi:10.1016/j.conengprac.2020.104394.

2019

  • Hassanpour H, Mhaskar P, House J, and Salsbury T. A Hybrid Modeling Approach for Fault Detection and Isolation of HVAC Systems. Computers & Chemical Engineering. Jul. 2019. doi:10.1016/j.compchemeng.2019.04.011.
  • Zhao Z, Li Y, Salsbury T, Alcala C, House J. Self-Optimizing Control of an Air Source Heat Pump. 2019 American Control Conference (ACC). Jul. 2019. LENSID: 029-873-208-324-086. doi:10.23919/acc.2019.8815006.

2018

  • Ebegbulem J, Guay M, House J, Salsbury T. Decentralized Proportional-Integral Extremum Seeking Control for HVAC Systems. 2018 IEEE Conference on Control Technology and Applications (CCTA). Aug. 2018. doi:10.1109/ccta.2018.8511534.

2017

  • Dong L, Li Y, House J, and Salsbury T. Mode Switching Control for a Multi-Functional Variable Refrigerant Flow System. Science and Technology for the Built Environment. Dec. 20, 2017. doi:10.1080/23744731.2017.1406275.
  • Mu B, Li Y, House J, and Salsbury T. Real-Time Optimization of a Chilled Water Plant with Parallel Chillers Based on Extremum Seeking Control. Applied Energy. Dec. 2017. doi:10.1016/j.apenergy.2017.09.072.
  • Salsbury T, and Alcala C. A Method for Setpoint Alarming Using a Normalized Index. Control Engineering Practice. Mar. 2017. doi:10.1016/j.conengprac.2016.12.002.

2016

  • Baojie Mu B, Li Y, Salsbury T, and House J. Optimization and Sequencing of Chilled-Water Plant Based on Extremum Seeking Control. 2016 American Control Conference (ACC). Jul. 2016. doi:10.1109/acc.2016.7525272.
  • Mu B, Li Y, House J, and Salsbury T. Experimental Evaluation of Anti-Windup Extremum Seeking Control for Airside Economizers. Control Engineering Practice. May 2016. doi:10.1016/j.conengprac.2016.02.008.

2015

  • Mu B, Li Y, Salsbury T, House J. Extremum Seeking Based Control Strategy for a Chilled-Water Plant with Parallel Chillers. Dynamic Systems and Control Conference (DSCC). Oct. 28, 2015. doi:10.1115/dscc2015-9949.
  • Salsbury T, and Alcala C. Two New Normalized EWMA-Based Indices for Control Loop Performance Assessment. 2015 American Control Conference (ACC). Jul. 2015. doi:10.1109/acc.2015.7170858.
  • Wallace M, Mhaskar P, House J, and Salsbury T. Offset-Free Model Predictive Control of a Heat Pump. Industrial & Engineering Chemistry Research. Jan. 20, 2015, doi:10.1021/ie5017915.

2014

  • Ma J, Qin S J, and Salsbury T. Application of Economic MPC to the Energy and Demand Minimization of a Commercial Building. Journal of Process Control. Aug. 2014. doi:10.1016/j.jprocont.2014.06.011.

2013

  • Ma J, Qin S J, and Salsbury T. Experimental Study of Economic Model Predictive Control in Building Energy Systems. 2013 American Control Conference (ACC). Jun. 2013. doi:10.1109/acc.2013.6580411.
  • Salsbury T, Mhaskar P, and Qin S J. Predictive Control Methods to Improve Energy Efficiency and Reduce Demand in Buildings. Computers & Chemical Engineering. Apr. 2013. doi:10.1016/j.compchemeng.2012.08.003.

2012

  • Wallace M, Das B, Mhaskar P, House J, and Salsbury T. Offset-Free Model Predictive Control of a Vapor Compression Cycle. Journal of Process Control. Aug. 2012. doi:10.1016/j.jprocont.2012.06.011.
  • Wallace M, McBride R, Aumi S, Mhaskar P, House J, and Salsbury T. Energy Efficient Model Predictive Building Temperature Control. Chemical Engineering Science. Feb. 2012. doi:10.1016/j.ces.2011.07.023.

2011

  • Ma J, Qin J S, and Salsbury T. Real-time Model Predictive Control for Energy and Demand Optimization of Multi-zone Buildings. ISGT 2011. Jan. 2011. doi:10.1109/isgt.2011.5759140.

2010

  • Salsbury T, and Singhal A. Shape-Based Stiction Detection Using Area Calculations. Book Chapter. Advances in Industrial Control. 2010, doi:10.1007/978-1-84882-775-2_9

2009

  • Salsbury, T. A Practical Algorithm for Diagnosing Control Loop Problems. Energy and Buildings. Jan. 1999. doi:10.1016/s0378-7788(98)00053-x.

2005

  • Salsbury T, and Singhal A. A New Approach for ARMA Pole Estimation Using Higher-Order Crossings. Proceedings of the 2005. American Control Conference. 2005. LENSID: 024-869-308-180-119, doi:10.1109/acc.2005.1470698.

1998

  • Salsbury, T. A Temperature Controller for VAV Air-Handling Units Based on Simplified Physical Models. HVAC&R Research. Jul. 1998. doi:10.1080/10789669.1998.10391404.

1997

  • Buswell R, Haves P, and Salsbury T. A Model-Based Approach to the Commissioning of HVAC Systems. 1997. LENSID: 100-513-863-112-518.
  • Salsbury T, and Diamond R. Model-Based Diagnostics for Air Handling Units. 1997. LENSID: 115-099-712-739-907.

1996

  • Haves P, Salsbury T, and Wright J. Condition Monitoring in HVAC Subsystems Using First Principles Models. ASHRAE Transactions. 1996. LENSID: 034-299-710-698-208.
  • Haves P, Jorgensen D, Salsbury T, and Dexter A. Development and Testing of a Prototype Tool for HVAC Control System Commissioning. Report. 1996. LENSID: 046-988-603-320-970.
  • Salsbury T. Fault Detection and Diagnosis in HVAC Systems Using Analytical Models. Dissertation Thesis. 1996. LENSID: 115-099-712-739-907.

1994

  • Benouarets M, Dexter A, Fargus R, Haves P, Salsbury T, and Wright J. Model-Based Approaches to Fault Detection and Diagnosis in HVAC Systems. Proc. System Simulation in Buildings' 94. 1994. LENSID: 052-565-623-474-662.