Field Study on Thermal Performance of a Green Office in Bangkok, Thailand: A Possibility of Increasing Temperature Set-Points

Authors: T. Sikram, M. Ichinose, R. Sasaki

Abstract:

In the tropics, indoor thermal environment is usually provided by a cooling mode to maintain comfort all year. Indoor thermal environment performance is sometimes different from the standard or from the first design process because of operation, maintenance, and utilization. The field study of thermal environment in the green building is still limited in this region, while the green building continues to increase. This study aims to clarify thermal performance and subjective perception in the green building by testing the temperature set-points. A Thai green office was investigated twice in October 2018 and in May 2019. Indoor environment variables (temperature, relative humidity, and wind velocity) were collected continuously. The temperature set-point was normally set as 23 °C, and it was changed into 24 °C and 25 °C. The study found that this gap of temperature set-point produced average room temperature from 22.7 to 24.6 °C and average relative humidity from 55% to 62%. Thermal environments slight shifted out of the ASHRAE comfort zone when the set-point was increased. Based on the thermal sensation vote, the feeling-colder vote decreased by 30% and 18% when changing +1 °C and +2 °C, respectively. Predicted mean vote (PMV) shows that most of the calculated median values were negative. The values went close to the optimal neutral value (0) when the set-point was set at 25 °C. The neutral temperature was slightly decreased when changing warmer temperature set-points. Building-related symptom reports were found in this study that the number of votes reduced continuously when the temperature was warmer. The symptoms that occurred by a cooler condition had the number of votes more than ones that occurred by a warmer condition. In sum, for this green office, there is a possibility to adjust a higher temperature set-point to +1 °C (24 °C) in terms of reducing cold sensitivity, discomfort, and symptoms. All results could support the policy of changing a warmer temperature of this office to become “a better green building”.

Keywords: Thermal environment, green office, temperature set-point, comfort.

Digital Object Identifier (DOI): doi.org/10.6084/m9.figshare.12488954

References:

[1] BCI ASIA, Green Building Market Report South East Asia 2014, (Online). Available: https://www.bciasia.com/wp-content/uploads/ 2015/03/Green.Building.Market.Report.2014.pdf (Accessed: 29 June 2019).
[2] K.W. Tham, Indoor air quality and its effects on humans—A review of challenges and developments in the last 30 years. Energy Build. 130 (2016) 637-650.
[3] B. Lin, Y. Liu, Z. Wang, Z. Pei, M. Davies, Measured energy use and indoor environment quality in green office buildings in China, Energy Build. 129 (2016) 9–18.
[4] C. Ionescu, T. Baracu, G.-B. Vlad, H. Necula, A. Badea, The historical evolutionof the energy efficient buildings, Renew. Sustain. Energy Rev. 49 (2015) 243–253.
[5] Eco-Business, Freezing in the tropics - Asean’s air-con conundrum (Online). Available: https://www.iea.org/southeastasia/ (Accessed: 30 June 2019).
[6] S.A. Damiati, S.A. Zaki, H.B. Rijal, S. Wonorahardjo, Field study on adaptive thermal comfort in office buildings in Malaysia, Indonesia, Singapore, and Japan during hot humid season, Build. Environ.109 (2016) 208-223.
[7] M.P. Deuble, R.J. de Dear, Green occupants for green buildings: the missing link, Build. Environ. 56 (2012) 21–27.
[8] BCO. 24_C Study: comfort, productivity and energy consumption: case study. British Council for Offices; 2010.
[9] M. Lakeridou, M.Ucci, A. Marmot, I. Ridley, The potential of increasing cooling set-points in air-conditioned offices in the UK, Applied Energy 94 (2012) 338–348.
[10] N. Yamtraipat, J. Khedari, J. Hirunlabh, J.Kunchornrat, Assessment of Thailand indoor set-point impact on energy consumption and environment, Energy Policy. 34 (2006) 765–770.
[11] ASHRAE, Thermal Environmental Conditions for Human Occupancy, ANSI/ASHRAE standard, 2013, 55—2013.
[12] ISO 9920, Ergonomics of the Thermal Environment: Estimation of Thermal Insulation and Water Vapour Resistance of a Clothing Ensemble International Standard, 2007.
[13] ČSN EN ISO 7730. Moderate thermal environment – Determination of the PMV and PPD indices and specification of the conditions for thermal comfort, Prague, 1997.
[14] F. Nicol, M.A. Humphreys, S. Roaf, Adaptive Thermal Comfort: Principles and Practice, Routledge, London, 2012.
[15] S. K. Jusuf, M. Ichinose, Y. Fukawa, S. Sattayakorn, Study on the thermal performance of office spaces in the tropics: A case study in Singapore, in: Proceedings of 34th International Passive and Low Energy Architecture.