Dr. Paramjit Singh Bilga is a Professor in the Department of Mechanical Engineering at Guru Nanak Dev Engineering College, Ludhiana, an Autonomous and Oldest Government Aided Engineering College of Punjab, affiliated to I. K. Gujral Punjab Technical University, Jalandhar - Kapurthala, Punjab, India. He completed his B.E. (Mechanical) from Panjab University, Chandigarh in 1989, M.Tech (Energy Studies) and Ph.D. from Centre for Energy Studies, Indian Institute of Technology, Delhi in 1994 and 2009 respectively. He has twenty-five years of teaching and research experience in the field of design, analysis, modeling, simulation and optimization of thermal energy, environment and safety engineering systems. He has done the project and research work during his graduation as well as post-graduation programs in the area of Refrigeration and Air Conditioning and is teaching this subject.