Field survey of the thermal comfort, quality of sleep and typical occupant behaviour in the bedrooms of Japanese houses during the hot and humid season

Shukuya

et al. 2020

J. Inst. Engineering

The energy use in residential dwellings has been increasing due to increasing use of modern electric appliances to make the lifestyle easier, entertaining and better. One of the major purposes of indoor energy use is for improving indoor thermal environment for adjusting thermal comfort. Along with the use of passive means like the use of mechanical devices, the occupants in any dwellings use active means such as the use of natural ventilation, window opening, and clothing adjustment. In fact, the use of active means when the outdoor environment is good enough might be more suitable to improve indoor thermal environment than the use of mechanical air conditioning units, which necessarily require electricity. Therefore, the people in developing countries like Nepal need to understand to what extent the occupants can use active means to manage their own indoor thermal comfort. The use of active means during good outdoor environment might be an effective way to manage increasing energy demand in the future. We have made a field survey on the occupants’ adaptive behaviors for thermal comfort in a Japanese condominium equipped with Home Energy Management System (HEMS). Online questionnaire survey was conducted in a condominium with 356 families from November 2015 to October 2016 to understand the occupants’ behaviors. The number of 17036 votes from 39 families was collected. The indoor air temperature, relative humidity and illuminance were measured at the interval of 2-10 minutes to know indoor thermal environmental conditions. The occupants were found using different active behaviors for thermal comfort adjustments even in rather harsh summer and winter. Around 80% of the occupants surveyed opened windows when the outdoor air temperature was 30⁰C in free running (FR) mode and the clothing insulation was 0.93 clo when the outdoor air temperature was 0⁰C. The result showed that the use of mechanical heating and cooling was not necessarily the first priority to improve indoor thermal environment. Our result along with other results in residential buildings showed that the adaptive behaviors of the occupants are one of the primary ways to adjust indoor thermal comfort. This fact is important in enhancing the energy saving building design.

Section: Adaptive Behaviorscontrasting

confidence: 57%

Importance of Behavioral Adjustments for Adaptive Thermal Comfort in a Condominium with HEMS System

Shukuya

et al. 2020

J. Inst. Engineering

“…The questionnaire survey was designed based on [2,5] All aforementioned scale was presented in Table 2. Besides that, questions about respondents' sleep quality have been asked in this questionnaire survey.…”

Section: Questionnaire Surveymentioning

confidence: 99%

Field Survey of Thermal Comfort and Sleep Quality in the Bedrooms with Different Cooling Strategies in Malaysia

Sadzli

Zaki

et al. 2019

KSS

This study aims to determine the indoor comfort temperature before sleep and after wake up in air-conditioning (AC) mode with different adaptive cooling strategies. Two units of guest rooms on the university campus were used with a total of 20 participants. The arbitrary-controlled AC setting (case 1) and control of thermostat setting by 3∘C higher than case 1 with installing of cool bed padding (case 2) were employed as cooling strategies in this study. The measurement parameters were indoor and outdoor air temperatures, globe temperature, relative humidity, air velocity, and AC electricity consumption. The questionnaire survey has also been distributed twice a day for “before going to bed” and “after waking up” during measurement simultaneously. It was observed that thermal sensation vote (TSV) indicated for both cases were within -1 ≤ TSV ≤ 1 and respondents might accept the present condition for both cases. Mean thermal preference (TP) in both cases either “before going to bed” and “after waking up” was found mostly close to “0 no change” (0.1 ≤ TP ≤ 0.3) for all cases. Overall comfort (OC) ranged between 4.7 and 4.9 for both cases, indicating for “comfortable.” However, air movement sensation (AMS) shows respondent felt weak airflow inside the room for all ventilation strategies. The skin moisture sensation (SMS) shows value pointed to neutral feeling for all cases. The comfort temperature obtained by Griffiths’ method was approximately 24∘C and 25∘C that for case 1 and case 2, respectively. Meanwhile, most of the respondents experienced calmness during sleeping and satisfied with their sleep in both cases. Sleep efficiency index (SEI) shows case 2 was higher rather than case 1. It seems the second adaptive cooling strategy might effective for reducing AC energy consumption by about 32% and increase 2% of SEI without affecting respondents’ thermal comfort.

“…A number of projects have researched about occupant behaviour in offices [1][2][3][4][5][6][7][8][9][10][11], university buildings [12,13] and dwellings [14][15][16][17][18][19][20][21][22]. The occupant behaviour model developed for office buildings [9] may not apply to Japanese offices and research about occupant behaviour is needed for Japanese offices.…”

Section: Introductionmentioning

confidence: 99%

Study on Behavioural Adaptation for the Thermal Comfort and Energy Saving in Japanese Offices

Humphreys

Nicol

2020

J. Inst. Engineering

Office workers use a variety of adaptive opportunities to regulate their indoor thermal environment. The behavioural adaptations such as window opening, clothing adjustments, heating/cooling use are one of the important factors for the adaptive thermal comfort. It is well-known that they are the most important contributors in the adaptive thermal comfort model. Thus, if we understand the behavioural adaptation properly, we can explain the mechanism of the adaptive model. In addition, the indoor thermal environment is often adjusted using the air conditioning in Japanese office building to improve the thermal comfort and productivity. Thus, it is necessary to conduct research on the behavioural adaptation in the offices because the occupant behavior is different to the dwellings. In order to record the seasonal differences in behavioural adaptation and to develop an adaptive algorithm for Japanese offices, we measured temperatures in 11 office buildings and conducted the thermal comfort and occupant behaviour survey for over a year in Japanese offices. We collected 4,660 samples from about 1350 people. The proportion of ‘open window’ in the free running mode (neither heating or cooling being used) is significantly higher than that of the air-conditioned mode. The behavioural adaptation is related to the outdoor air temperature. The behavioural adaptation predicted by the regression analysis is in good agreement with the measured data. These findings can be applied to the building thermal simulation to predict the behavioural adaptation and energy use in office buildings.