scholarly journals Effectiveness of a Cool Bed Linen for Thermal Comfort and Sleep Quality in Air-Conditioned Bedroom under Hot-Humid Climate

2021 ◽  
Vol 13 (16) ◽  
pp. 9099
Author(s):  
Sheikh Ahmad Zaki ◽  
Mohamad Faizal Rosli ◽  
Hom Bahadur Rijal ◽  
Farah Nurhanis Hassan Sadzli ◽  
Aya Hagishima ◽  
...  

Comfort temperature and sleep quality involving 20 participants were determined in two cases: Case A (arbitrary, controlled air-conditioner setting) and Case B (adjustment of 3 °C higher than the setting of Case A with cool bed linen). Data of indoor thermal comfort and electricity consumption were collected every night throughout the measurement period. Questionnaires on thermal comfort and sleep quality were distributed twice a night for a duration of three nights for each case; the first night was for respondents’ adaptation and the following two nights were for measurement. The sleep quality of the respondents was objectively measured using a commercially available activity tracker. Results found that most respondents were thermally comfortable in both cases, with 39% lower energy consumption reported for Case B compared to Case A. The thermal conditions of Case B were found to be more tolerable than those of Case A. Most respondents reported to have a calm and satisfied sleep for both cases. Comfort temperature and Sleep Efficiency Index (SEI) were found to be maintained in both cases.

2019 ◽  
Author(s):  
Ng Wai Tuck ◽  
Sheikh Ahmad Zaki ◽  
Aya Hagishima ◽  
Hom Bahadur Rijal ◽  
Mohd Azuan Zakaria ◽  
...  

An effective passive cooling strategy is essential for reducing energy consumption in a residential building without ignoring thermal comfort. Therefore, a field measurement on the thermal performance of a corner terrace house in Kuala Lumpur was conducted to reveal the effectiveness of free running (FR) with four different approaches – no ventilation, full ventilation, day ventilation, and night ventilation. The measurement was done for all bedrooms and family area on the first floor. Also, mixed mode (MM) consisting of natural ventilation, mechanical ventilation with ceiling fan, and cooling with an air-conditioner that represents the actual condition of this house was also measured at living and dining area on the ground floor for comparison. The results reveal that FR from all approaches recorded a mean indoor air temperature of approximately 31 ∘C. The actual thermal condition of the house with MM on the ground floor was recorded at 30 ∘C, 1 ∘C lower than FR approach on the first floor. When compared with relevant international standards on predicting indoor comfort temperature based on outdoor temperature, FR was approximately 5 ∘C higher than predicted temperature based on American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 55 (2017), 3.4 ∘C higher than European Standard EN15251 and 1.5 ∘C higher than adaptive thermal comfort equation (ACE) for hot-humid climate. In comparison, MM performed better and was closer to relevant international standards, especially ACE for the hot-humid climate. As a conclusion, FR is not suitable for a hot-humid climate such as Malaysia to achieve a comfortable indoor thermal environment without any assisted ventilation use in MM.


Buildings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 78
Author(s):  
Kumar Biswajit Debnath ◽  
David P. Jenkins ◽  
Sandhya Patidar ◽  
Andrew D. Peacock

According to the India Energy Security Scenario 2047, the number of residential air conditioner (A/C) units may increase seven-fold by 2037 as compared to 2017. Also, the related energy consumption might increase four times in the next two decades, according to India’s National Cooling Action Plan. Therefore, the study of occupant cooling behaviour is essential to reduce and manage the significant electricity demand, helping to formulate and implement climate-specific cooling policies, and to adopt low-energy and low-cost technologies at mass-market scale. The study aims to analyse residential electricity consumption in order to investigate occupant behaviour, especially for thermal comfort by using space cooling and mechanical ventilation technologies. Among the five climate zones in India, this study focuses on the occupant behaviour in a warm-humid climate using Auroville as a case study, where climate analysis of the past 30 years demonstrated progression towards unprecedented warmer weather in the last five years. In this study, electricity consumption data from 18 households (flats) were monitored for seven months (November 2018–June 2019). The study also elaborated the limitations faced while monitoring and proposed a data filling methodology to create a complete daily profile for analysing occupant behaviour through electricity consumption. The results of the data-driven approach demonstrated the characteristics and complexities in occupant behaviour and insight on the operation of different technologies to attain thermal comfort in residential buildings in an increasingly warming climate.


Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 326
Author(s):  
Wiwik Budiawan ◽  
Kazuyo Tsuzuki

Thermal comfort is crucial in satisfaction and maintaining quality sleep for occupants. In this study, we investigated the comfort temperature in the bedroom at night and sleep quality for Indonesian students during summer and winter. Eighteen male Indonesian students aged 29 ± 4 years participated in this study. The participants had stayed in Japan for about six months. We evaluated the sleep parameters using actigraphy performed during summer and winter. All participants completed the survey regarding thermal sensation, physical conditions, and subjective sleepiness before sleep. The temperature and relative humidity of participants’ bedrooms were also measured. We found that the duration on the bed during winter was significantly longer than that during summer. However, sleeping efficiency during winter was significantly worse than that during summer. The bedroom temperature of the participants was in the range of comfort temperature in Indonesia. With the average bedroom air temperature of 22.2 °C, most of the participants still preferred “warm” and felt “slightly comfortable” during winter. The average comfort temperature each season calculated using the Griffiths method was 28.1 °C during summer and 23.5 °C during winter. In conclusion, differences in adaptive action affect bedroom thermal conditions. Furthermore, habits encourage the sleep performance of Indonesian students.


2020 ◽  
Vol 223 ◽  
pp. 110072 ◽  
Author(s):  
Ng Wai Tuck ◽  
Sheikh Ahmad Zaki ◽  
Aya Hagishima ◽  
Hom Bahadur Rijal ◽  
Fitri Yakub

2020 ◽  
Vol 197 ◽  
pp. 02006
Author(s):  
Miguel Chen Austin ◽  
Milvia Castillo ◽  
Ángela de Mendes Da Silva ◽  
Dafni Mora

The increasing concern expressed by building designers in Panama, due to new building-energy regulations, regarding sustainable development goals and energy efficiency, is leading architects to reanalyse their design strategies and evaluate the vernacular architecture. The main implications of the hot-humid climate characteristics stipulate that the need for cooling of indoor environments drives buildings’ design and settlements. This work aims to assess the use of bioclimatic architecture strategies in three existing building typologies design in Panama, in terms of thermal comfort performance. The approach adopted here is to compare and analyse the vernacular architecture with current architecture. Besides, to evaluate bioclimatic architecture strategies based on recent investigations and the guidelines proposed by Givony, Olgyay, among others. A numerical assessment was performed on the dynamic simulation software DesignBuilder, where the building’s passive strategies are evaluated in terms of operative temperature, relative humidity (rH), PMV, PPD, and discomfort hours (DH). All three houses, the HVA, HCA, and HRES were tested in three different locations within Panama City. Results showed that the strategies in HVA perform best for reducing rH levels, but the HRES performs best in overall thermal comfort performance, apart yet from the high rH levels encountered.


2013 ◽  
Vol 457-458 ◽  
pp. 1498-1502
Author(s):  
Wen Pei Sung ◽  
Rong Chen ◽  
Hung Chang Chang ◽  
Y.K. Zhao

Taiwan is located in the subtropical zone. The climate in summer is hot with high humidity. In order to establish a comfortable office, it needs a lot of active devices, such as: air conditioner to maintain the suitable indoor temperature and humidity. In this study, a business office in the South District Public Health Center, Taichung City is conducted. According to our findings for the office, although the measured indoor temperature was closer to a comfortable temperature during the winter, the occupants of the indoor space still felt excessively warm. By contrast, the occupants of the same space achieved thermal comfort during the summer. This implies that most of the office occupants preferred a cooler environment with a lower temperature. In addition, because the summers in Taiwan are humid and hot, the occupants of an indoor space tend to feel uncomfortable because of the high humidity regardless of whether the temperature is maintained in a comfortable zone. A lower temperature (approximately 21.2-23.9°C) indirectly reduces humidity, thereby making the occupants comfortable.


2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Maryam Qays Oleiwi ◽  
Mohd Farid Mohamed

Past years have witnessed the popularity of traditional Malay house as a common housing type in Malaysia. However, double-storey house has become one of the common types of low-rise housing in Malaysia. Several passive cooling strategies have been adopted to cope with the hot-humid climate of Malaysia. In this study, the thermal comfort of a double-storey house was examined when different passive cooling strategies that were adopted from traditional Malay houses were applied using IES-VE 2019 building simulation software. The simulation was conducted for various design strategies such as changing concrete roof tiles to clay roof tiles, adding two small openings to the attic, removing the ceiling between the upper floor and the attic, and extending the overhang by 50% of its length for all the four facades. All these strategies were tested and compared between full-day natural ventilation and without any ventilation. The thermal comfort of these strategies was graphically defined based on the operative temperature. These analyses revealed that protecting the building envelope by extending the overhang by 50% of its length for all the four facades could ensure the best thermal comfort is achieved compared to other selected strategies. Recommendations for further studies are also outlined in this paper.


Sign in / Sign up

Export Citation Format

Share Document