Design and operation optimization of an air conditioning system through simulation: an hour-by-hour simulation study

Document Type: Research Paper


1 Department of Marine and Mechanical Engineering, Chabahar Maritime University, 99717-56499, Chabahar, Iran

2 Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia


In the present research, performance validation of a Heating, Ventilation, and Air Conditioning (HVAC) system operating in a library building was conducted. The operating HVAC system was studied in terms of the provided indoor air conditions and energy consumption level. The fieldwork measurements showed that the HVAC system is not capable of providing the desired indoor air conditions based on the ASHRAE standards. Therefore, two deciding design and operating parameters namely, chilled water cooling coil number of rows and chilled water temperate were investigated to achieve possible improvement in the system performance. For this purpose, different numbers of rows for cooling coil design at different chilled water temperatures were examined. TRNSYS software was employed to investigate the hourly effect of the variables on the system for a whole year of operation.Based on the simulation results, the provided indoor air conditions were appropriate and within the comfort area with the two-row configuration cooling coil. However, the energy performance of the system indicated that the two-row configuration with 10 chilled water temperature was superior in terms of energy consumption, and could provide the desired indoor air conditions, thus it was recommended to be implemented in the existing system.


[1] Straus D.C., Cooley J.D., Wong W.C., Jumper C.A., Studies on the Role of Fungi in Sick Building Syndrome, Archives of Environmental Health (2004) 58: 475-478.

[2] Guptam S. Khare M., Goyal R., Sick Building Syndrome– A Case Study in a Multistory Centrally Air-Conditioned Building in the Delhi City, Building and Environment (2007)  42: 2797-2809.

[3] Mallick F.H., Thermal Comfort and Building Design in Tropical Climates, Energy and Buildings (1996) 23: 161-167.

[4] Sekhar S.C., Willem H.C., Impact of Airflow Profile on Indoor Air Quality –A Tropical Study, Building and Environment (2004) 39: 255-266.

[5] Chan K.T., Chow W.K., Energy Impact of Commercial Building Envelopes in the Sub-Tropical Climate, Applied Energy (1998) 60: 21-39.

[6] Li Z., Chen W., Deng S., Lin Z., The Characteristics of Space Cooling Load and Indoor Humidity Control for Residence in the Subtropics, Building and Environment (2006) 41: 1137-1147.

[7] Henderson H.I., Rengarajan k., Shirey D.B., The Impact of Comfort Control on Air Conditioner Energy Use in Humid Climates, ASHRAE Transaction (1992) 98: 104-112.

[8] Martin R.H., Martinez, F.J.R., Gomez E.V., Thermal Comfort Analysis of a Low Temperature Waste Energy Recovery System: SIECHP, Energy and Buildings (2008) 40: 561-572.

[9] Martinez F.J.R., Alvarez-Guerra Plasencia M.A., Gomez E.V., Diez F.V., Martin R.H., Design and Experimental Study of Mixed Energy Recovery System, Heat Pipe and Indirect Evaporative Equipment for Air Conditioning, Energy and Buildings (2003) 35: 1021-1030.

[10] Yau Y.H., The Use of a Double Heat Pipe Heat Exchanger System for Reducing Energy Consumption of Treating Ventilation Air in an Operating Theatre – A Full Year Energy Consumption Model Simulation, Energy and Buildings (2008) 40: 917-925.

[11] Ahmadzadehtalatapeh M., Yau Y.H., Fully fresh Air Air-Conditioning System Equipped with Double Heat Pipe Based Heat Recovery Technology, International Journal of Engineering (2013) 26: 461-467.

[12] ASHRAE, ASHRAE Standard 55-2004 Atlanta USA (2004).

[13] Yau Y.H., Lee S.K., Feasibility Study of an Ice Slurry-Cooling Coil for HVAC and R Systems in a Tropical Building, Applied Energy (2010) 87: 2699–2711.

[14] Lee S.K., The Energy and Economic Studies of an Ice Slurry System in a Tropical Building , M.S. Thesis, University of Malaya, Malaysia (2008).

[15] Bearg D., Indoor Air Quality and Humidity Control, Air Conditioning, Heating and Refrigeration News (1992).

[16] ASHRAE, ASHRAE Handbook of Fundamentals, SI Edition, Atlanta, USA (2009).