Indoor thermal environment optimal control for thermal comfort and energy saving based on online monitoring of thermal sensation

A thermal comfort field study was investigated in residential buildings of cold regions in transition season during which the indoor thermal environment conditions are measured, the thermal sensation value of the occupants is questioned and recorded. A seven-point thermal sensation scale was used to evaluate the thermal sensation. The statistical method was used to analyze the data and the conclusions are as follows in transition season: clothing increase in 0.1clo when the indoor air temperature is lowered by 1°C; and clothing will be a corresponding increase in 0.06clo when the outdoor air temperature is lowered by 1°C; clothing also varies with gender, age, weight and thermal history and other related; the measured thermal neutral temperature is 21.3°C; and the minimum accepted temperature is 11.4 °C in transition season in cold regions. Most people choose to change clothes, switch and other passive measures, and occasionally take active measures of heater, electric fans and others.

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Impact of ventilation system type on indoor thermal environment and human thermal comfort in a ceiling cooling room

Thermal Science ◽

10.2298/tsci210108277w ◽

2021 ◽

pp. 277-277

Author(s):

Xiaozhou Wu ◽

Genglin Liu ◽

Jie Gao ◽

Shuang Wu

Keyword(s):

Thermal Comfort ◽

Air Temperature ◽

Thermal Environment ◽

Thermal Sensation ◽

Ventilation System ◽

Physical Parameters ◽

Curtain Wall ◽

Indoor Thermal Environment ◽

Human Thermal Comfort ◽

System Type

A ceiling cooling (CC) system integrated with a mechanical ventilation system is an advanced HVAC system for the modern office building with glass curtain wall. In this paper, considering the influence of heat transfer of external envelope, the indoor thermal environment and human thermal comfort were objectively measured and subjectively evaluated in a ceiling cooling room with mixing ventilation (MV) or underfloor air distribution (UFAD). Indoor physical parameters and human skin temperatures were measured as the chilled ceiling surface temperature and supply air temperature were 17.1?C-17.6?C and 22.2?C - 22.6?C. Simultaneously, 16 subjects (8 males and 8 females) were selected to subjectively evaluate the thermal environment. The results showed that the difference between mean radiant temperature and air temperature in the occupied zone was 0.8?C with CC+MV and 1.2?C with CC+UFAD, and the indoor air velocity was 0.17m/s with CC+MV and 0.13m/s with CC+UFAD. In addition, the calculated and measured thermal sensation votes with CC+MV were all slightly less than those with CC+UFAD. Therefore, ventilation system type had a slight impact on the indoor thermal environment and human thermal comfort in the ceiling cooling room.

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Does a neutral thermal sensation determine thermal comfort?

Building Services Engineering Research and Technology ◽

10.1177/0143624418754498 ◽

2018 ◽

Vol 39 (2) ◽

pp. 183-195 ◽

Cited By ~ 16

Author(s):

Sally Shahzad ◽

John Brennan ◽

Dimitris Theodossopoulos ◽

John K Calautit ◽

Ben R Hughes

Keyword(s):

Thermal Comfort ◽

Thermal Environment ◽

Thermal Sensation ◽

Building Design ◽

Thermal Preference ◽

Practical Application ◽

Comfort Zone ◽

Indoor Thermal Environment ◽

Human Thermal Comfort ◽

Comfort Condition

The neutral thermal sensation (neither cold, nor hot) is widely used through the application of the ASHRAE seven-point thermal sensation scale to assess thermal comfort. This study investigated the application of the neutral thermal sensation and it questions the reliability of any study that solely relies on neutral thermal sensation. Although thermal-neutrality has already been questioned, still most thermal comfort studies only use this measure to assess thermal comfort of the occupants. In this study, the connection of the occupant’s thermal comfort with thermal-neutrality was investigated in two separate contexts of Norwegian and British offices. Overall, the thermal environment of four office buildings was evaluated and 313 responses (three times a day) to thermal sensation, thermal preference, comfort, and satisfaction were recorded. The results suggested that 36% of the occupants did not want to feel neutral and they considered thermal sensations other than neutral as their comfort condition. Also, in order to feel comfortable, respondents reported wanting to feel different thermal sensations at different times of the day suggesting that occupant desire for thermal comfort conditions may not be as steady as anticipated. This study recommends that other measures are required to assess human thermal comfort, such as thermal preference. Practical application: This study questions the application of neutral thermal sensation as the measure of thermal comfort. The findings indicate that occupant may consider other sensations than neutral as comfortable. This finding directly questions the standard comfort zone (e.g. ASHRAE Standard 55) as well as the optimum temperature, as many occupants required different thermal sensations at different times of the day to feel comfortable. These findings suggest that a steady indoor thermal environment does not guarantee thermal comfort and variations in the room temperature, which can be controlled by the occupant, need to be considered as part of the building design.

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Field Investigation of Indoor Thermal Environment and Thermal Adaption of Dalian Residences in Winter

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.361-363.458 ◽

2013 ◽

Vol 361-363 ◽

pp. 458-463 ◽

Cited By ~ 1

Author(s):

Pei Sheng Zhu ◽

Fei Guo ◽

Tong Zhu ◽

Shu Guo Liu

Keyword(s):

Thermal Comfort ◽

Thermal Environment ◽

Thermal Sensation ◽

Field Investigation ◽

Adaptation Measures ◽

Indoor Thermal Environment ◽

Temperature Range ◽

Neutral Temperature

To study the thermal environment of Dalian residences, in winter from 2011 to 2012 field investigation were conducted on indoor thermal environment, thermal sensation and adaptation measures. Thermal comfort instrument was used, and 102 subjective questionnaires in 36 families were collected. The acceptability to the thermal environment is 93.2%. The neutral temperature is 20.44°C, and the expected temperature is 20.81°C. 80% of the acceptable temperature range is 17.38-24.28°C. 57% of subjects think it is dry indoor and measures shall be taken for humidification.

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Research on Energy Saving Potential of Indoor Thermal Environment Control based on Thermal Sensation

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/199/3/032080 ◽

2018 ◽

Vol 199 ◽

pp. 032080

Author(s):

Wenhong Yu ◽

Chaowen Jiang ◽

Ziyang Gong

Keyword(s):

Energy Saving ◽

Thermal Environment ◽

Thermal Sensation ◽

Indoor Thermal Environment ◽

Energy Saving Potential ◽

Environment Control ◽

Thermal Environment Control

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Evaluation of Indoor Thermal Environment in a Radiant-Cooled-Floor Office Building in Malaysia

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.564.228 ◽

2014 ◽

Vol 564 ◽

pp. 228-233 ◽

Cited By ~ 1

Author(s):

Qi Jie Kwong ◽

Mohamad Afri Arsad ◽

Nor Mariah Adam

Keyword(s):

Thermal Comfort ◽

Thermal Environment ◽

Cooling System ◽

Thermal Sensation ◽

Office Building ◽

Air Velocity ◽

Variable Air Volume ◽

Indoor Thermal Environment ◽

Radiant Cooling ◽

Comfort Parameters

This paper presents the findings of a thermal comfort survey conducted in a tropical green office building. The building was installed with a slab-integrated radiant cooling system, which operated concurrently with an integrated variable-air-volume system. Evaluation of indoor thermal environment was made, where both objective and subjective assessments were carried out. The air temperature, air velocity, relative humidity and surface temperatures were measured by using calibrated sensors. Based on the data collected from the field assessment, the thermal comforts indices with expectancy factor were calculated. The results showed that thermal comfort parameters were within the comfort range specified in a local guideline, except for the air velocity profile. Besides, discrepancy between the Predicted Mean Vote (PMV) with expectancy factor and Actual Mean Vote (AMV) was found, which showed that the former still overestimated the thermal sensation of occupants although an expectancy factor of 0.5 was used.

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Improvements in Energy Saving and Thermal Environment after Retrofitting with Interior Insulation in Intermittently Cooled Residences in Hot-Summer/Cold-Winter Zone of China: A Case Study in Chengdu

Energies ◽

10.3390/en14102776 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2776

Author(s):

Xin Ye ◽

Jun Lu ◽

Tao Zhang ◽

Yupeng Wang ◽

Hiroatsu Fukuda

Keyword(s):

Energy Saving ◽

Thermal Environment ◽

Real Life ◽

Average Energy ◽

Experimental Result ◽

Cold Winter ◽

The South ◽

Indoor Thermal Environment ◽

Space Cooling

Space cooling is currently the fastest-growing end-user in buildings. The global warming trend combined with increased population and economic development will lead to accelerated growth in space cooling in the future, especially in China. The hot summer and cold winter (HSCW) zone is the most densely populated and economically developed region in China, but with the worst indoor thermal environment. Relatively few studies have been conducted on the actual measurements in the optimization of insulation design under typical intermittent cooling modes in this region. This case study was conducted in Chengdu—the two residences selected were identical in design, but the south bedroom of the case study residence had interior insulation (inside insulation on all opaque interior surfaces of a space) retrofitted in the bedroom area in 2017. In August 2019, a comparative on-site measurement was done to investigate the effect of the retrofit work under three typical intermittent cooling patterns in the real-life scenario. The experimental result shows that interior insulation provides a significant improvement in energy-saving and the indoor thermal environment. The average energy savings in daily cooling energy consumption of the south bedroom is 42.09%, with the maximum reaching 48.91%. In the bedroom with interior insulation retrofit, the indoor temperature is closer to the set temperature and the vertical temperature difference is smaller during the cooling period; when the air conditioner is off, the room remains a comfortable temperature for a slightly longer time.

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Study on the Thermal Performance of the Vernacular Dwellings in Wei-He Plain of Shaanxi Province

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.476-478.1589 ◽

2012 ◽

Vol 476-478 ◽

pp. 1589-1595

Author(s):

Yi Ping Zhu ◽

Xi Liao ◽

Shu Yun Wu ◽

Jing Luo ◽

Yuan Jiang ◽

...

Keyword(s):

Energy Saving ◽

Thermal Insulation ◽

Thermal Performance ◽

Thermal Environment ◽

Local Area ◽

Shaanxi Province ◽

Indoor Thermal Environment ◽

Questionnaire Surveys

Based on indoor thermal environment test and questionnaire surveys, the paper studies on thermal insulation capacity and indoor thermal environment of the vernacular dwellings in Wei-he Plain of Shaanxi Province, China, and analyses their heating methods and application status. Besides, the popularity of sustainable techniques in local area has been evaluated and summarized. Moreover, the paper discusses the present problems in local indoor thermal environment and energy-saving status.

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Towards Sustainable Development: Building’s Retrofitting with PCMs to Enhance the Indoor Thermal Comfort in Tropical Climate, Malaysia

Sustainability ◽

10.3390/su13073614 ◽

2021 ◽

Vol 13 (7) ◽

pp. 3614

Author(s):

Zeyad Amin Al-Absi ◽

Mohd Isa Mohd Hafizal ◽

Mazran Ismail ◽

Azhar Ghazali

Keyword(s):

Climate Change ◽

Sustainable Development ◽

Thermal Comfort ◽

Phase Change Materials ◽

Thermal Environment ◽

High Energy ◽

Transition Temperatures ◽

Indoor Thermal Environment ◽

Adaptive Thermal Comfort ◽

The Difference

Building sector is associated with high energy consumption and greenhouse gas emissions, which contribute to climate change. Sustainable development emphasizes any actions to reduce climate change and its effect. In Malaysia, half of the energy utilized in buildings goes towards building cooling. Thermal comfort studies and adaptive thermal comfort models reflect the high comfort temperatures for Malaysians in naturally conditioned buildings, which make it possible to tackle the difference between buildings’ indoor temperature and the required comfort temperature by using proper passive measures. This study investigates the effectiveness of building’s retrofitting with phase change materials (PCMs) as a passive cooling technology to improve the indoor thermal environment for more comfortable conditions. PCM sheets were numerically investigated below the internal finishing of the walls. The investigation involved an optimization study for the PCMs transition temperatures and quantities. The results showed significant improvement in the indoor thermal environment, especially when using lower transition temperatures and higher quantities of PCMs. Therefore, the monthly thermal discomfort time has decreased completely, while the thermal comfort time has increased to as high as 98%. The PCM was effective year-round and the optimum performance for the investigated conditions was achieved when using 18mm layer of PCM27-26.

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Energy-saving potential of intermittent heating system: Influence of composite phase change wall and optimization strategy

Energy Exploration & Exploitation ◽

10.1177/0144598720969217 ◽

2020 ◽

pp. 014459872096921

Author(s):

Yanru Li ◽

Enshen Long ◽

Lili Zhang ◽

Xiangyu Dong ◽

Suo Wang

Keyword(s):

Energy Consumption ◽

Thermal Comfort ◽

Phase Change ◽

Air Temperature ◽

Indoor Air ◽

Thermal Environment ◽

Optimization Strategy ◽

Indoor Thermal Environment ◽

Indoor Thermal Comfort ◽

Intermittent Heating

In the Yangtze River zone of China, the heating operation in buildings is mainly part-time and part-space, which could affect the indoor thermal comfort while making the thermal process of building envelope different. This paper proposed to integrate phase change material (PCM) to building walls to increase the indoor thermal comfort and attenuate the temperature fluctuations during intermittent heating. The aim of this study is to investigate the influence of this kind of composite phase change wall (composite-PCW) on the indoor thermal environment and energy consumption of intermittent heating, and further develop an optimization strategy of intermittent heating operation by using EnergyPlus simulation. Results show that the indoor air temperature of the building with the composite-PCW was 2–3°C higher than the building with the reference wall (normal foamed concrete wall) during the heating-off process. Moreover, the indoor air temperature was higher than 18°C and the mean radiation temperature was above 20°C in the first 1 h after stopping heating. Under the optimized operation condition of turning off the heating device 1 h in advance, the heat release process of the composite-PCW to the indoor environment could maintain the indoor thermal environment within the comfortable range effectively. The composite-PCW could decrease 4.74% of the yearly heating energy consumption compared with the reference wall. The optimization described can provide useful information and guidance for the energy saving of intermittently heated buildings.

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