Assessment of Building Envelope Thermal Performance Using Overall Thermal Transfer Value (OTTV) at Labuang Baji Hospital, Makassar
DOI:
https://doi.org/10.70716/reswara.v4i3.730Keywords:
OTTV, Energy Efficiency, Building Envelope, Hospital, Thermal ComfortAbstract
Hospitals are public service buildings with high energy consumption because they operate continuously and require stable thermal comfort. One aspect that affects building energy efficiency is the performance of the building envelope in resisting heat transfer from the outdoor environment. This study examines the Overall Thermal Transfer Value (OTTV) as an indicator of energy efficiency in Building B of Labuang Baji Hospital, Makassar. The assessment was conducted through field observation and measurement of building-envelope parameters, including façade orientation, wall area, glazing area, material type, thermal transmittance, shading conditions, and solar radiation entering the indoor spaces. OTTV analysis was carried out on the fourth, fifth, and sixth floors with reference to SNI 6389:2020, which specifies a maximum OTTV limit of 35 W/m². The results indicate that the average OTTV values ranged from 81.04 W/m² on the fourth floor to 85.93 W/m² on the fifth floor, all of which substantially exceeded the national standard. The northwest façade consistently recorded the highest average OTTV values (92.80–94.03 W/m²), whereas the south façade exhibited the lowest values (69.00–74.38 W/m²), although these also remained well above the allowable limit. These findings demonstrate that the existing building envelope has not yet achieved the required level of thermal efficiency and contributes to increased cooling loads. The results also identify the northwest façade and upper floors as priority targets for energy retrofit interventions. Recommended improvement measures include the use of high-performance glazing, the installation of external shading devices, optimization of the window-to-wall ratio, and improved wall insulation to reduce heat gain and enhance overall building energy efficiency.
References
Al-Masrani, S. M., & Al-Obaidi, K. M. (2019). Dynamic shading systems: A review of design parameters, platforms and evaluation strategies. Automation in Construction, 102, 195–216. https://doi.org/10.1016/j.autcon.2019.01.014
Ascione, F., Bianco, N., De Masi, R. F., & Vanoli, G. P. (2013). Rehabilitation of the building envelope of hospitals: Achievable energy savings and microclimatic control on varying the HVAC systems in Mediterranean climates. Energy and Buildings, 60, 125–138. https://doi.org/10.1016/j.enbuild.2013.01.021
ASHRAE. (1975). ASHRAE Standard 90-75: Energy conservation in new building design.
Badan Standardisasi Nasional. (2020). SNI 6389:2020. Konservasi energi selubung bangunan pada bangunan gedung.
Bellia, L., De Falco, F., & Minichiello, F. (2013). Effects of solar shading devices on energy requirements of standalone office buildings for Italian climates. Applied Thermal Engineering, 54(1), 190–201. https://doi.org/10.1016/j.applthermaleng.2013.01.039
Chaitanya, B., Bahadur, V., Thakur, A. D., & Raj, R. (2018). Biomass-gasification-based atmospheric water harvesting in India. Energy, 165, 610–621. https://doi.org/10.1016/j.energy.2018.09.183
Chan, A. L. S. (2023). Evaluating the appropriateness of adopting a single Overall Thermal Transfer Value and its implication to building energy regulation. Journal of Building Engineering, 76, 107225. https://doi.org/10.1016/j.jobe.2023.107225
Chan, L. S. (2021). Investigating the thermal performance and Overall Thermal Transfer Value (OTTV) of air-conditioned buildings under the effect of adjacent shading against solar radiation. Journal of Building Engineering, 44, 103211. https://doi.org/10.1016/j.jobe.2021.103211
Chou, S. K., & Lee, Y. K. (1988). A simplified Overall Thermal Transfer Value equation for building envelopes. Energy, 13(8), 657–670. https://doi.org/10.1016/0360-5442(88)90096-5
Cui, H., Zhang, L., Yang, H., & Shi, Y. (2024). Optimizing thermal comfort and energy efficiency in hospitals with PCM-enhanced wall systems. Energy and Buildings, 323, 114740. https://doi.org/10.1016/j.enbuild.2024.114740
Elnour, M., Fadli, F., Himeur, Y., Petri, I., Rezgui, Y., Meskin, N., & Ahmad, A. M. (2022). Performance and energy optimization of building automation and management systems: Towards smart sustainable carbon-neutral sports facilities. Renewable and Sustainable Energy Reviews, 162, 112401. https://doi.org/10.1016/j.rser.2022.112401
Guo, S., Wang, W., & Zhou, Y. (2022). Research on energy saving and economy of old buildings based on parametric design: A case study of a hospital in Linyi City, Shandong Province. Sustainability, 14(24), 16681. https://doi.org/10.3390/su142416681
Gupta, V., & Deb, C. (2023). Envelope design for low-energy buildings in the tropics: A review. Renewable and Sustainable Energy Reviews, 186, 113650. https://doi.org/10.1016/j.rser.2023.113650
Halawa, E., Ghaffarianhoseini, A., Ghaffarianhoseini, A., Trombley, J., Hassan, N., Baig, M., Yusoff, S. Y., & Ismail, M. A. (2018). A review on energy conscious designs of building façades in hot and humid climates: Lessons for (and from) Kuala Lumpur and Darwin. Renewable and Sustainable Energy Reviews, 82, 2147–2161. https://doi.org/10.1016/j.rser.2017.08.061
International Energy Agency. (2021). Energy efficiency 2021. https://www.iea.org/reports/energy-efficiency-2021
International Organization for Standardization. (2018). ISO 50001:2018. Energy management systems—Requirements with guidance for use.
Irvandi, M., Soebiyan, V., & Tomasowa, R. (2021). OTTV based shading devices optimization for multi-storey building in tropical Jakarta. IOP Conference Series: Earth and Environmental Science, 794(1), Article 012239. https://doi.org/10.1088/1755-1315/794/1/012239
Kapoor, N. R., Kumar, A., Meena, C. S., Kumar, A., Alam, T., Balam, N. B., & Ghosh, A. (2021). A systematic review on indoor environmental quality in naturally ventilated school classrooms: A way forward. Advances in Civil Engineering, 2021, Article 8851685. https://doi.org/10.1155/2021/8851685
Lionar, R., Kroll, D., Soebarto, V., Sharifi, E., & Aburas, M. (2024). A review of research on self-shading façades in warm climates. Energy and Buildings, 314, 114203. https://doi.org/10.1016/j.enbuild.2024.114203
Ma, S., Deng, W., Lu, J., Zhou, T., & Liu, B. (2023). Investigation of thermal comfort and preferred temperatures for healthcare staff in hospitals in Ningbo, China. Journal of Building Engineering, 80, 108029. https://doi.org/10.1016/j.jobe.2023.108029
Ma, Z., Cooper, P., Daly, D., & Ledo, L. (2012). Existing building retrofits: Methodology and state-of-the-art. Energy and Buildings, 55, 889–902. https://doi.org/10.1016/j.enbuild.2012.08.018
Shah, I., Soh, B., Lim, C., Lau, S.-K., & Ghahramani, A. (2023). Thermal transfer and temperature reductions from shading systems on opaque facades: Quantifying the impacts of influential factors. Energy and Buildings, 278, 112604. https://doi.org/10.1016/j.enbuild.2022.112604
Szokolay, S. (2012). Introduction to architectural science: The basis of sustainable design (3rd ed.). Routledge.
Zahari, A. F., Mulyadi, R., & Jamala, N. (2023). The effect of shading devices on OTTV (Overall Thermal Transfer Value) value of office buildings: Case study of PT Industri Kapal Indonesia (IKI) Building. ASTONJADRO, 12(3), 868–885. https://doi.org/10.32832/astonjadro.v12i3.14255
Zune, M., Tubelo, R., Rodrigues, L., & Gillott, M. (2021). Improving building thermal performance through an integration of Passivhaus envelope and shading in a tropical climate. Energy and Buildings, 253, 111521. https://doi.org/10.1016/j.enbuild.2021.111521
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Syamsuddin Mustafa, Syamfitriani Asnur, Andi Besse Opu (Author)
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
