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Building Simulation 2014, 7(4): 345-359 https://doi.org/10.1007/s12273-013-0151-6
Research Article | Issue | Published: 29 October 2013

Thermo-economic optimization of rooftop unit’s evaporator coil for energy efficiency and thermal comfort

Show Author's Information Vahid Vakiloroaya1( ),  Bijan Samali2,  Ahmad Fakhar3,  Kambiz Pishghadam4
Center for Built Infrastructure Research, School of Electrical, Mechanical and Mechatronic Systems, University of Technology Sydney, PO Box 123, Broadway, Sydney, NSW, 2007, Australia
Center for Built Infrastructure Research, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
Department of Mechanical Engineering, Faculty of Engineering, Azad University of Kashan, Iran
Department of Sustainable and Net-Zero Energy Building (NZEB) Solutions, Giacomini Inc., Vancouver, BC, Canada
Keywords:
energy saving, HVAC, design optimization, direct expansion evaporator coil, thermo-economic analysis
Cite this article:
Vakiloroaya V, Samali B, Fakhar A, et al. Thermo-economic optimization of rooftop unit’s evaporator coil for energy efficiency and thermal comfort. Building Simulation, 2014, 7(4): 345-359. https://doi.org/10.1007/s12273-013-0151-6
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Abstract Full text About this article

In this paper, the optimization-simulation approach is proposed to investigate energy saving potential of an air-cooled direct expansion rooftop package air conditioning system by refining the model of the HVAC system components and deriving optimal configuration for evaporator coil subject to technical constraints. In this method the frontal area of the evaporator coil is maintained as constant and the variation of other geometrical parameters on the thermal and economical performance of the system is investigated. An actual air-cooled rooftop package of a real-world commercial building in hot and dry climate conditions is used for experimental data collection. Both inputs and outputs are measured from the field monitoring in two summer weeks. Based on the mathematical models and using collected data, modules incorporating the proposed optimal redesign procedure were embedded in a transient simulation tool. A mixed heuristic- deterministic optimization algorithm was implemented in the transient tool to determine the synthesis and design variables that influence the cost and energy efficiency of each configuration. Available experimental results were compared to predicted results to validate the model. Afterwards, the computer model was used to predict how changes in cooling coil geometry would affect the building thermal comfort, the cost and energy consumption of the system.


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About this article

Thermo-economic optimization of rooftop unit’s evaporator coil for energy efficiency and thermal comfort

Show Author's information Vahid Vakiloroaya1( ), Bijan Samali2, Ahmad Fakhar3, Kambiz Pishghadam4
Center for Built Infrastructure Research, School of Electrical, Mechanical and Mechatronic Systems, University of Technology Sydney, PO Box 123, Broadway, Sydney, NSW, 2007, Australia
Center for Built Infrastructure Research, School of Civil and Environmental Engineering, University of Technology Sydney, Australia
Department of Mechanical Engineering, Faculty of Engineering, Azad University of Kashan, Iran
Department of Sustainable and Net-Zero Energy Building (NZEB) Solutions, Giacomini Inc., Vancouver, BC, Canada

Abstract

In this paper, the optimization-simulation approach is proposed to investigate energy saving potential of an air-cooled direct expansion rooftop package air conditioning system by refining the model of the HVAC system components and deriving optimal configuration for evaporator coil subject to technical constraints. In this method the frontal area of the evaporator coil is maintained as constant and the variation of other geometrical parameters on the thermal and economical performance of the system is investigated. An actual air-cooled rooftop package of a real-world commercial building in hot and dry climate conditions is used for experimental data collection. Both inputs and outputs are measured from the field monitoring in two summer weeks. Based on the mathematical models and using collected data, modules incorporating the proposed optimal redesign procedure were embedded in a transient simulation tool. A mixed heuristic- deterministic optimization algorithm was implemented in the transient tool to determine the synthesis and design variables that influence the cost and energy efficiency of each configuration. Available experimental results were compared to predicted results to validate the model. Afterwards, the computer model was used to predict how changes in cooling coil geometry would affect the building thermal comfort, the cost and energy consumption of the system.

Keywords: energy saving, HVAC, design optimization, direct expansion evaporator coil, thermo-economic analysis

References(25)

ANSI/ASHRAE Standard 140 (2007). Standard Method of Test for the Evaluation of Building Energy Analysis Computer Program. Atlanta, GA, USA: American Society of Heating, Refrigerating and Air-Conditioning.
CFA Afonso (2006). Recent advances in building air conditioning systems. Applied Thermal Engineering, 26: 1961-1971.
DOI Google Scholar
J Arias, P Lundqvist (2006). Heat recovery and floating condensing in supermarkets. Energy and Buildings, 38: 73-81.
DOI Google Scholar
ARI Standard 540 (2004). Performance rating of positive displacement refrigerant compressors and compressor units. Air Conditioning and Refrigeration Institute, Arlington, VA, USA.
ASHRAE (2004). ASHRAE Standard 55: Thermal Environment Conditions for Human Occupancy. Atlanta, GA, USA: American Society of Heating, Refrigerating and Air-Conditioning.
ASHRAE (2009). ASHRAE Handbook: Fundamentals. Atlanta, GA, USA: American Society of Heating, Refrigerating and Air-Conditioning Engineers.
EM Barreira, COR Negrao, CJL Hermes (2013). Thermoeconomic analysis and optimization of residential split-type air conditioners. Applied Thermal Engineering, 50: 629-636.
DOI Google Scholar
A Bendaoud, M Ouzzane, Z Aidoun, N Galanis (2010). A new modeling approach for the study of finned coils with CO2. International Journal of Thermal Sciences, 49: 1702-1711.
DOI Google Scholar
Council of Australian Governments (2012). Guide to Best Practice Maintenance and Operation of HVAC Systems for Energy Efficiency. Department of Climate Change and Energy Efficiency, Australia.
AS Huzayyin, SA Nada, HF Elattar (2007). Air-side performance of a wavy-finned-tube direct expansion cooling and dehumidifying air coil. International Journal of Refrigeration, 30: 230-244.
DOI Google Scholar
ISO Standard 7730 (1994). Moderate Thermal Environment, Determination of PMV and PPD Indices and Specifications of the Conditions for Thermal Comfort. Geneva: International Organization for Standardization.
TS Lee, WC Wu, JC Jiang (2012). Improved energy performance of air-cooled water chillers with innovative condenser coil configurations—Part ΙΙ: Experimental validation. International Journal of Refrigeration, 35: 2212-2222.
DOI Google Scholar
Minitab (2010). Minitab User's Guide Release 16. State College, PA, USA: Minitab Inc.
N Nassif (2012). The impact of air filter pressure drop on the performance of typical air-conditioning systems. Building Simulation, 5: 345-350.
DOI Google Scholar
P Sarntichartsak, S Thepa (2013). Modeling and experimental study on the performance of an inverter air conditioner using R410A with evaporatively cooled condenser. Applied Thermal Engineering, 51: 597-610.
DOI Google Scholar
S Sanaye, HR Malekmohammadi (2004). Thermal and economical optimization of air conditioning units with vapor compression refrigeration system. Applied Thermal Engineering, 24: 1807-1825.
DOI Google Scholar
TE Schmidt (1949). Heat transfer calculations for extended surfaces. Refrigeration Engineering, 1949(April): 351-357.
Google Scholar
SC Sekhar, LT Tan (2009). Optimization of cooling coil performance during operation stages for improved humidity control. Energy and Building, 41: 229-233.
DOI Google Scholar
TRNSYS (2006). TRNSYS Software: A Transient System Simulation Program, version 16. Available: http://sel.me.wisc.edu/trnsys.
V Vakiloroaya (2013). Design optimization of the cooling coil for HVAC energy saving and comfort enhancement. Environmental Progress & Sustainable Energy, 32: 1209-1216.
DOI Google Scholar
V Vakiloroaya, J Madadnia, B Samali (2013a). Modeling and performance prediction of an integrated central cooling plant for HVAC energy efficiency improvement. Building Simulation, 6: 127-138.
DOI Google Scholar
V Vakiloroaya, QP Ha, B Samali (2013b). Energy-efficient HVAC systems: Simulation-empirical modeling and gradient optimization. Automation in Construction, 31: 176-185.
DOI Google Scholar
B Wang, L Han, W Shi, X Li (2012). Modeling method of scroll compressor based on suction gas bypass. Applied Thermal Engineering, 37: 183-189.
DOI Google Scholar
CC Wang, KY Chi, CJ Chang (2000). Heat transfer and friction characteristics plain fin-and-tube heat exchangers. Part II: Correlation. International Journal of Heat and Mass Transfer, 43: 2693-2700.
DOI Google Scholar
FWH Yik, J Burnett, I Prescott, (2001). Predicting air-conditioning energy consumption of group of buildings using different heat rejection methods. Energy and Buildings, 33: 151-166.
DOI Google Scholar
Publication history
Copyright

Publication history

Received: 08 March 2013
Revised: 07 June 2013
Accepted: 16 July 2013
Published: 29 October 2013
Issue date: August 2014

Copyright

© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2013
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