Effect of high performance Fenestration on Commercial Building Energy Consumption
Sagaiyaraj B.**,Jahandideh M.M.*, Yarmand H.*, Kazi.S.N.*, Abu Bakar.M.*
* Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
** Blue Snow Consulting & Engineering Sdn Bhd(744370-V),Malaysia
This paper presents a parametric study for estimation of energy saving potential of various types of fenestration in commercial buildings in Malaysia. The study is based on simulation of building energy consumption for various thermal conductivity (U- values) and shading coefficient (SC) values of constituents. The results show that by using low SC value window materials the building energy consumption could be reduced by 22% which could be further lower by 4% using low U-value window materials. The results also show that the effect of the SC of a window is more important for increasing building energy efficiency compared to its U-value.
Keywords: Building Energy; Energy saving; Conservation; Fenestration; Shading Coefficient.
Energy consumption of the building and its impact to the environment have become a key issue faced by the building professionals such as Architects, MEP Engineers and Sustainability Engineers. In Malaysia, there is a growing concern about energy consumption, especially electricity use in buildings, and its implication that increases global greenhouse gas emissions. With the rapid economic growth and improvement in living standards, there has been a remarkable increase in the commercial building energy use (Lam & Ng, 1994; Li & Lam, 2001).
A significant amount of the electricity consumption is used for air-conditioning systems of the buildings. Recent energy audits on air-conditioned commercial buildings have revealed that air-conditioning accounts for 57 % of the total electricity use in typical commercial buildings in a tropical region such as Kuala Lumpur, where the summer is
long, hot and humid (Saidur, 2009) .
In commercial buildings, a large portion of facade area is glass, these ‘curtain-walled’ facades comprise of a large portion of the heat ingress into a building i.e. increasing the heat load. This issue is crucial for tropical climate areas such as Malaysia where solar intensity is higher and daytime period is one of the longest(Wong, Wan, & Lam, 2010).
The weather pattern in Malaysia is primarily summer all round the year and is non-seasonal (Oldeman & Frere, 1982) . Two important factors have high influence on energy consumption of the HVAC system of a building are the Shading Coefficient (SC) and U-value of the Glazing system, especially one that has extremely high window-to-wall ratio (Cordoba, Macias, & Espinosa, 1998) .
In this paper, results from simulations carried out on the building by Carrier’s Hourly Analysis Program (HAP) shows the effect of glazing SC as well as U-value on the total energy consumption of the building. It also compares the two factors to determine which parameter is of more crucial to the energy saving potential of the building.
Carrier’s Hourly Analysis Program (HAP) performs a true hour-by-hour energy analysis, using measured weather data for all 8,760 hours of the year to calculate building heat transfer and loads, air system operation, and airconditioning plant equipment operation.
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E-mail address: Bernard @bluesnowenergy.com