Faculty Directory

Hwang, Yunho

Hwang, Yunho

Research Professor
Co-director - Center for Environmental Energy Engineering
Mechanical Engineering
Center for Environmental Energy Engineering
Maryland Applied Graduate Engineering
Maryland Energy Innovation Institute
4164 Glenn. L. Martin Hall Building


  • Ph.D. ('97), M.S. ('95) - Mechanical Engineering

    University of Maryland (College Park, USA)
  • B.S. ('83) - Mechanical Engineering 

    Korea University (Seoul, South Korea)


Dr. Yunho Hwang is a research professor and co-director of the Center for Environmental Energy Engineering (CEEE).  He is a worldly-known expert for “Energy Efficiency and New Innovative Energy Systems Research” in the field of refrigeration and air-conditioning (RAC). He started his industrial career at Samsung Electronics in 1983, developed energy-efficient heat pump systems, and replaced ozone-depleting R12 with R134a in household refrigerators. Since he joined the University of Maryland in 1993, he developed R-22 alternative refrigerants for air-conditioning systems and then started his research on enhanced CO2 systems. From 1997, he started Energy Efficiency and Heat Pumps Consortium as a director and successfully developed multiple innovative energy-efficient and sustainable RAC technologies. In addition to developing energy-efficient technologies such as two-stage CO2 split cycle, saturation cycle, and hybrid separate sensible and latent cooling technology, he has initiated new innovative researches on “Not-in-kind” Refrigeration Systems beyond sorption technologies such as elastocaloric cooling systems and electrochemical compression for natural refrigerants. As an educator and researcher, he advised UMD students teams for multiple national and international collegiate design competitions, introduced innovative thermal systems concepts, and helped teams win either First or Second place.  

He is an ASME Fellow, an ASHRAE Fellow, and a member of ASME, ASHRAE, SAE, and IIR. Currently, he serves as a President of Commission B1 and a past chair of the LCCP Working Group for the IIR, and an operating agent of ANNEX 54 for IEA HPT.  He also serves Energy, Elsevier (Netherlands) as a subject Editor since 2015 and Int. Journal of AC&R, World Scientific (US), as an editor since 2013.


Working Fluids, Heat Transfer, Compact Heat Exchangers, Vapor Compression, Sorption Cycles and Caloric Cooling, Electrochemical Compression, Alternative Cooling Technologies and Applications, Advanced Energy Conversion Systems and Integration of Thermal Systems, Renewable Energy, and Waste Heat Utilization

Following list shows current research projects being conducted.

  • Elastocaloric cooling
  • Electrochemical compression
  • Hybrid separate sensible and latent cooling technology
  • Next Generation Heat Exchanger
  • VRF system modleing and field test
  • Microgrid system optimization
  • Roving Comporter

He teaches following courses:

  • ENPM808C: Ocean Energy Harvesting
  • ENME635: Energy Conversion Systems
  • ENME701: Sustainable Energy Production and Utilization
  • ENPM 651: Heat Transfer for Modern Applications
  • ENME423: Building Cooling, Heating, and Power Integration
  • ENME489M: Special Topics in Mechanical Engineering, Ultra-low Energy Use Appliance Design II
  • ENME489M: Special Topics in Mechanical Engineering, Ultra-low Energy Use Appliance Design I
  • ENME808L: Ultra-low Energy Use Appliance Design II
  • ENME808P: Ultra-low Energy Use Appliance Design I


His innovative research during the last 35 years has resulted in 360 publications including two books, nine book chapters, and 17 patents. His very high research impact is proven by Scopus data: h_index 41 with 5,178 citations. He was selected as an author of one of the top 1% most highly cited papers in the author's field worldwide (2016).  His six publications were selected as either most cited articles or most downloaded articles from Elsevier. 

Three Most cited Articles from Elsevier

  • Review of cold storage materials for air conditioning application, Volume 35, Issue 8, December 2012, Pages 2053-2077, Int. J. of Refrigeration, Gang Li, Yunho Hwang*, Reinhard Radermacher
  • Refrigerant injection for heat pumping/air conditioning systems: Literature review and challenges discussions, Int. J. of Refrigeration, Volume 34, Issue 2, March 2011, Pages 402-415, Xing Xu, Yunho Hwang*, Reinhard Radermacher
  • Optimization of propane pre-cooled mixed refrigerant LNG plant, Volume 31, Issues 6-7, May 2011, Pages 1091-1098, Applied Thermal Eng., Abdullah Alabdulkarem, Amir Mortazavi, Yunho Hwang*, Reinhard Radermacher, Peter Rogers

Three Most downloaded Articles from Int. J. of Refrigeration

  • A review of elastocaloric cooling: Materials, cycles and system integrations, April 2016, Suxin Qian, Yunlong Geng, Yi Wang, Jiazhen Ling, Yunho Hwang*, Reinhard Radermacher, Ichiro Takeuchi, Jun Cui
  • Recent advances in vapor compression cycle technologies, December 2015, Chasik Park, Hoseong Lee, Yunho Hwang*, Reinhard Radermacher
  • Review of solar thermal air conditioning technologies, March 2014, Ali Al-Alili, Yunho Hwang*, Reinhard Radermacher

Farewell, Dr. Tao Cao

CEEE alumnus and post-doctoral researcher moved on

CEEE Wins Best Session Paper Award for Experimental Methods at The 15th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics (HEFAT)

The paper is titled "Design Optimization and Experimental Validation of Heat Exchangers Utilizing High Performance, Non-round Tubes.”

CEEE Awarded Peter Ritter von Rittinger International Heat Pump Award

This year the award was presented virtually at 13th International Heat Pump Conference.

CEEE Graduate Research Assistant Accepted into Future Faculty Program

Joseph Baker hopes to help others better understand energy engineering

CEEE Selected as Quarterfinalists in DOE Solar Desalination Competition

The team was awarded $50,000 and has the potential to win up to $1 million as they advance in the competition

Dr. Yunho Hwang Receives 2020 Dean's Outstanding Performance Award in Research

Dr. Hwang has spent over 20 years at CEEE and now serves as co-director for the center

Fall 2019 Consortium "Best Student Presentation" Announced

Ellery Klein was a sponsor favorite for his excellent audience engagement and confidence with his topic.

Dr. Hwang and Dr. Aute Named New CEEE Co-Directors

They aim to expand CEEE's status as one of the leading Centers for HVAC&R Research in the world

Hwang Becomes Operating Agent of IEA Annex 54

Also new Associate Editor of ASME Journal

Prof. Yunho Hwang Recognized as ASHRAE Fellow

Received the award at the Society's Winter Conference in Atlanta, Georgia.

Zhenning Li Wins Best Student Consortium Presentation Award

Research was on 'CoilDesigner Updates'.

Mechanical Engineering at ASME IMECE Conference

Professor Radermacher was a plenary speaker and ME alumnus Ryan Kennett won Best Student Paper at this year’s conference.

Researchers Introduce RoCo, a Mobile Personal Heating and Cooling Device

UMD Invention Has Potential to Cut Energy Costs in Residential and Large Building AC

Meet the visiting students!

Students from universities abroadvisit CEEE to work in labs, gain research and cultural experience.

Professor from Beijing visits UMD to research ways to increase HVAC efficiency and reduce energy use

Rang Tu is an assistant professor from the University of Science and Technology Beijing in China.

Hyundai Motor Company engineer and global R&D expert conducts research with CEEE

Jae Yeon Kim's project is Efficient architecture designs of vehicle thermal management system (VTMS) for Eco friendly vehicles using numerical simulations.

The University of Maryland Receives $50,000 Grant from Dominion Foundation

Award supports new research on high efficiency solar-powered cooling systems.

UMD Startup To Solve Energy Conversion Challenges in Thermal Systems

Optimized Thermal Systems provides engineering consulting for HVAC&R systems.

Dasgupta, Fourney and Hwang Named ASME Fellows

Three Mechanical Engineering faculty named American Society of Mechanical Engineers Fellows

2014 Annual Wrap Up

Center for Environmental Engineering News Highlights of 2014

Hwang Invited to Energy Editorial Board, Chairs ASME 2015 Conference and Delivers Keynote

Professor Yunho Hwang invited to Energy editorial board, chairs ASME 2015 conference and delivers keynote at International Symposium on Refrigeration Technology.