Title: Energy, exergy and economic analysis for ON/OFF cycle and VFD HVAC cooling systems

Authors: Waleed M.A. Hamanah; Mahmoud Kassas; Ahmet Z. Sahin; Ibrahim M. El-Amin

Addresses: Electrical Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia ' Electrical Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia ' Mechanical Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia ' Electrical Engineering Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia

Abstract: A comparison of energy, exergy rate and economic analyses for an air conditioning ON/OFF cycle and variable frequency drive (VFD) HVAC systems with heat-mass exchange calculations were performed. The study considered several key performance parameters including; energy consumption, energy saving, exergy destruction rate, exergy efficiency, CO² emission, the coefficient of performance (COP), and cost analysis for both HVAC systems. The total energy consumption, exergy destruction, and CO² emission are lower when a VFD HVAC is used, as compared with an ON/OFF cycle HVAC system. The total exergy destruction decreases by more than 20%, on average, when a VFD is used when compared with the case of the ON/OFF cycle. Thus, this study reveals that, when a VFD is used, the energy efficiency and exergy efficiency increase by more than 37% and 10%, respectively.

Keywords: energy savings; exergy destruction; variable frequency drives; FD ON/OFF cycle; heating; ventilation; and air conditioning; HVAC.

DOI: 10.1504/IJEX.2019.099293

International Journal of Exergy, 2019 Vol.28 No.4, pp.355 - 379

Received: 20 Jun 2018
Accepted: 09 Jan 2019
Published online: 25 Apr 2019 *

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