Reducing outdoor air temperature, improving thermal comfort, and saving buildings’ cooling energy demand in arid cities – Cool paving utilization

2021 ◽  
Vol 68 ◽  
pp. 102762
Author(s):  
Amir Aboelata
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Demand ◽  
Outdoor Air ◽  
Cooling Energy Demand

scholarly journals Air Distribution and Air Handling Unit Configuration Effects on Energy Performance in an Air-Heated Ice Rink Arena

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 693 ◽  
Author(s):  
Mehdi Taebnia ◽  
Sander Toomla ◽  
Lauri Leppä ◽  
Jarek Kurnitski
Keyword(s):  
Temperature Gradient ◽  
Air Temperature ◽  
Indoor Air ◽  
Energy Demand ◽  
Energy Performance ◽  
Air Distribution ◽  
Air Handling Unit ◽  
Cooling Coil ◽  
Indoor Conditions ◽  
Cooling Energy Demand

Indoor ice rink arenas are among the foremost consumers of energy within building sector due to their exclusive indoor conditions. A single ice rink arena may consume energy of up to 3500 MWh annually, indicating the potential for energy saving. The cooling effect of the ice pad, which is the main source for heat loss, causes a vertical indoor air temperature gradient. The objective of the present study is twofold: (i) to study vertical temperature stratification of indoor air, and how it impacts on heat load toward the ice pad; (ii) to investigate the energy performance of air handling units (AHU), as well as the effects of various AHU layouts on ice rinks’ energy consumption. To this end, six AHU configurations with different air-distribution solutions are presented, based on existing arenas in Finland. The results of the study verify that cooling energy demand can significantly be reduced by 38 percent if indoor temperature gradient approaches 1 °C/m. This is implemented through air distribution solutions. Moreover, the cooling energy demand for dehumidification is decreased to 59.5 percent through precisely planning the AHU layout, particularly at the cooling coil and heat recovery sections. The study reveals that a more customized air distribution results in less stratified indoor air temperature.

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

2020 ◽  
Vol 15 (3) ◽  
pp. 163-170
Author(s):  
Rajan KC ◽  
Hom Bahadur Rijal ◽  
Masanori Shukuya ◽  
Kazui Yoshida
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Use ◽  
Thermal Environment ◽  
Residential Buildings ◽  
Outdoor Environment ◽  
Adaptive Behaviors ◽  
Outdoor Air ◽  
Indoor Thermal Environment ◽  
Indoor Thermal Comfort

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.

scholarly journals Improved Human Thermal Comfort with Indoor PCM-Enhanced Tiles in Living Spaces in the Arabian Gulf

2018 ◽  
Vol 57 ◽  
pp. 04001 ◽  
Author(s):  
Albert Al Touma ◽  
Djamel Ouahrani
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
Residential Buildings ◽  
Arabian Gulf ◽  
Weather Conditions ◽  
Building Envelope ◽  
Human Thermal Comfort ◽  
Outdoor Environments ◽  
Radiant Temperature ◽  
Cooling Energy Demand

Al-Majlis is the living space in residential buildings of the Arabian Gulf, and is where occupants spend most of their time. For this reason, the human thermal comfort in this space is of extreme importance and is often compromised due to hot outdoor weather conditions. In contrast with many thermal discomfort mitigation methods in outdoor environments, which become unadvisable in indoor spaces, this study investigates the effect of adding PCM-enhanced tiles to portions of the indoor envelope on the occupant’s thermal comfort and the space cooling energy demand. A simulation model of a space with tight building envelope in Qatar was developed on EnergyPlus with and without the addition of PCM-enhanced tiles. The selected country is a representative location of the Arabian Gulf. Considering different occupant’s positions, the addition of the tiles with PCM on their back was found to moderate the mean radiant temperature, operative temperature, Predicted Mean Vote (PMV) and Predicted Percentage of Dissatisfied (PPD), all of which signify an improvement in the human thermal comfort. Lastly, this change in the indoor envelope was found to save 3.3% of the space daily thermal cooling energy demand during one harsh summer representative day.

scholarly journals Thermal comfort and draught assessment in a modern open office building in Tallinn

2019 ◽  
Vol 111 ◽  
pp. 02013 ◽  
Author(s):  
Martin Kiil ◽  
Alo Mikola ◽  
Martin Thalfeldt ◽  
Jarek Kurnitski
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Energy Demand ◽  
Working Environment ◽  
Office Building ◽  
Indoor Climate ◽  
Air Velocity ◽  
Air Exchange Rate ◽  
Air Speed ◽  
Open Office

Modern office building users have high expectations about the working environment and thermal comfort, which requires the installation of complex technical systems such as combined cooling and ventilation. Room conditioning units of these systems must ensure temperature and ventilation control in a way that air velocity is low and the air temperature in acceptable range. Achieving air distribution avoiding draught is one of the key elements of a thermal comfort in modern office landscape. Higher air velocity in occupied zone is easily perceived as draught, which causes occupant dissatisfaction and complaints, as well as decrease in the productivity or effective floor space area. To reduce complaints, room air temperature setpoints or ventilation airflow rates are often modified, which may result in higher heating energy demand. In addition, excessive heating setpoint rise will not only consume more energy, but may cause health problems. Compared to cellular offices it is more difficult to ensure thermal comfort conditions in open office spaces where there are no walls for air flows. In addition, due to the higher number of employees it is more difficult to meet satisfactory conditions for everyone. The aim of this study was to evaluate thermal comfort parameters such as room air temperature, air speed and supply air temperature and how the users sense it in a modern office building in Tallinn, Estonia. Design room air temperature setpoints and air exchange rate were evaluated on open office spaces. Measured data with web-based indoor climate questionnaire was analysed. Results show which design and measured parameters make it possible to match the user comfort at all times.

scholarly journals A Field Study on Thermal Comfort and Cooling Load Demand Optimization in a Tropical Climate

2021 ◽  
Vol 13 (22) ◽  
pp. 12425
Author(s):  
Masoud Esfandiari ◽  
Suzaini Mohamed Zaid ◽  
Muhammad Azzam Ismail ◽  
Mohammad Reza Hafezi ◽  
Iman Asadi ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
Tropical Climate ◽  
High Energy ◽  
Sustainable Construction ◽  
Substantial Part ◽  
Cooling Load ◽  
Improve Energy Efficiency ◽  
Significant Difference ◽  
Cooling Energy Demand

Energy consumption to cool an indoor environment is a substantial part of total energy end-use, particularly in a tropical climate with high energy demand for cooling. To improve energy efficiency, cooling systems can be optimized using a variety of neutral indoor temperatures to maintain a balance between an occupant’s thermal comfort and cooling energy demand. This explanatory study investigated the thermal quality and cooling energy demand of a Platinum-certified office building in the tropical climate of Malaysia. The investigation aimed to suggest a balance between occupant thermal comfort and cooling energy demand. The thermal investigation includes an objective field measurement that implements environmental equipment to monitor thermal quality and a subjective occupant’s thermal feedback using a questionnaire survey. To calculate cooling energy demand, the total equivalent temperature difference method (TETD) is applied. The results suggested an occupant’s cooling sensation of around 24 °C, with no significant difference concerning age and gender. Cooling load calculation indicated a 36% energy reduction by increasing air temperature to 26 °C, for occupants to feel thermally comfortable in a tropical climate. These findings contribute to improving sustainable energy policies, sustainable construction, and thermal comfort improvement for a tropical climate.

scholarly journals An Assessment of the Spatial Comfort at the Open Piazza of Baiturrahman Mosque, Banda Aceh, Indonesia

2020 ◽  
Vol 9 (2) ◽  
pp. 50-62
Author(s):  
Laina Hilma Sari ◽  
Izziah Hasan ◽  
Erna Meutia
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Sensation ◽  
Field Measurements ◽  
Outdoor Thermal Comfort ◽  
Visual Comfort ◽  
Outdoor Air ◽  
White Marble ◽  
The Tropics ◽  
Banda Aceh

 The Baiturrahman Grand Mosque is well-known as the identity of Banda Aceh town, Indonesia. The extensive renovation was carried out in 2015 to the Mosque, presenting an open piazza coated with glossy white marble replacing the previous greeneries and grass. This change creates a much different thermal sensation of the prior environment. This condition also invites the contrast to respond and define spatial comfort, including thermal and visual comfort. Therefore, this study conducts an assessment of thermal and visual comfort at the open piazza, which was done through field measurements. The outdoor thermal comfort was calculated using the equations proposed by Sangkertadi that are appropriate for the tropics. The visual comfort was examined using the De Boer glare scale. The result shows the discomfort appearance for both thermal and visual comfort. The study gives recommendations, such as planting greeneries, providing more shades for achieving lower outdoor air temperature. Replacing the glossy marble with the diffusing and rough surface will reduce the glare for getting the more acceptable visual comfort against the marbles.

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