Numerical study to evaluate the human thermal comfort and the buildings energy demand inside the urban canyon

Author(s):  
A Vallati
2018 ◽  
Vol 57 ◽  
pp. 04001 ◽  
Author(s):  
Albert Al Touma ◽  
Djamel Ouahrani

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.


Atmosphere ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 12 ◽  
Author(s):  
Andre Santos Nouri ◽  
Dominik Fröhlich ◽  
Maria Matos Silva ◽  
Andreas Matzarakis

2020 ◽  
Vol 55 (5-6) ◽  
pp. 282-292
Author(s):  
N. Buyak ◽  
V. Deshko ◽  
I. Bilous ◽  
M. Gureev ◽  
O. Holubenko

The dynamic modeling of the energy characteristics of building structures with the help of energy-saving double-glazed windows was carried out in the work. The influence of different variants of windows replacement on the heat energy state of a typical mass building for various glazing coefficients in dynamic grid models created on the basis of the Energy Plus software product was analyzed. It is found that argon-filled glass, selective-coated glass on the outer and inner glass can reduce the energy requirement for the building by 8-10% compared to the double-glazed glass without selectively coating and filling the chambers with air. The load on the heating system is significantly different for the orientations North and South. It is assumed that the coefficient of glassy glass in the orientation of the South during the off-season (autumn / spring), less heating (switched on / off later). For North and South orientations, energy-saving windows with selective coating and / or filled up with inert gas cells have a different effect, which is explained by the coefficients of solar heat transmission, which was obtained on the basis of the simulation model. In addition, current standards in Ukraine do not provide all variants of the coefficients of optical transmittance characteristics of solar heat gains. In this work, a dynamic hourly simulation of the building energy demand in heated space for representative rooms N and S oriented for different glazing coefficients and window types has been carried out. Range of PMV change, average radiating temperature and air temperature in the room for the heating period were estimated. It was established that changing windows glazing can affect the PMV to change almost two times, which indicates the need for an integrated approach to the assessment of thermal comfort. Namely, the importance of taking into account the dynamic changes in the environment parameters and possible thermo-modernization were detected


2021 ◽  
Vol 21 (2) ◽  
pp. 130-147
Author(s):  
Ala'a Abbas Mahdi ◽  
Sara Mohammed Abbas

The current paper reports the analysis and design of air quality and human thermal comfort in rooms using impinging jet ventilation system at different occupant distribution. Theoretical and experimental studies at different situations of occupant distribution used the square cross sectional supply air duct with height from the foot level end (0.1h). This work presents a numerical study for predicting the indoor airflow and temperature distribution by adopting impinging jet ventilation system in office room. The emergence of the three zones flow field of an impinging jet is mostly divided into three distinguished zones: impingement zone, wall jet zone and free jet zone which produce excessive kinetic energy at the stagnation zone and distribute approximately in the longitudinal and lateral directions over the floor. Acceptable Air Distribution Performance Index (ADPI), effective temperature and ventilation efficiency were found at situations of occupant distribution (when the occupant located at the center of the room one sitting in front of the other gives optimum human thermal comfort if compared with the other situations of occupant distributions).


Buildings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 595
Author(s):  
Joanna Ferdyn-Grygierek ◽  
Izabela Sarna ◽  
Krzysztof Grygierek

In regions with temperate climates, the thermal insulation of buildings is increased to reduce the need for heating. It might significantly reduce human thermal comfort in the summer period. The problem can increase with global warming. The aim of the paper is to analyze the heating and cooling demand, as well as thermal comfort in a single-family house located in Poland for three climate scenarios (typical, real, and future weather data) and for two types of thermal insulation of external walls. In the study, two ways of cooling the building were taken into account: using split air conditioners and using fresh airflow provided through the opening of windows. The open area and the temperatures for opening windows have been optimized using a two-criteria function. The energy simulation was carried out in EnergyPlus 9.4 software. The multi-zone model was validated on the basis of the temperature measurement. The results showed that there will be a problem with ensuring thermal comfort in the future, especially in well-insulated buildings. The energy demand for cooling will be greater than the demand for heating. The use of passive cooling is a good solution for residential buildings in these regions, and the number of discomfort hours is small (max 5%).


ICCREM 2020 ◽  
2020 ◽  
Author(s):  
Boshuai Dong ◽  
Chunjing Shang ◽  
Ming Tong ◽  
Jianhong Cai

2017 ◽  
Vol 16 (9) ◽  
pp. 2097-2111 ◽  
Author(s):  
Mohanadoss Ponraj ◽  
Yee Yong Lee ◽  
Mohd Fadhil Md Din ◽  
Zainura Zainon Noor ◽  
Kenzo Iwao ◽  
...  

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3061 ◽  
Author(s):  
Shazia Noor ◽  
Hadeed Ashraf ◽  
Muhammad Sultan ◽  
Zahid Mahmood Khan

This study provides comprehensive details of evaporative cooling options for building air-conditioning (AC) in Multan (Pakistan). Standalone evaporative cooling and standalone vapor compression AC (VCAC) systems are commonly used in Pakistan. Therefore, seven AC system configurations comprising of direct evaporative cooling (DEC), indirect evaporative cooling (IEC), VCAC, and their possible combinations, are explored for the climatic conditions of Multan. The study aims to explore the optimum AC system configuration for the building AC from the viewpoints of cooling capacity, system performance, energy consumption, and CO2 emissions. A simulation model was designed in DesignBuilder and simulated using EnergyPlus in order to optimize the applicability of the proposed systems. The standalone VCAC and hybrid IEC-VCAC & IEC-DEC-VCAC system configurations could achieve the desired human thermal comfort. The standalone DEC resulted in a maximum COP of 4.5, whereas, it was 2.1 in case of the hybrid IEC-DEC-VCAC system. The hybrid IEC-DEC-VCAC system achieved maximum temperature gradient (21 °C) and relatively less CO2 emissions as compared to standalone VCAC. In addition, it provided maximum cooling capacity (184 kW for work input of 100 kW), which is 85% higher than the standalone DEC system. Furthermore, it achieved neutral to slightly cool human thermal comfort i.e., 0 to −1 predicted mean vote and 30% of predicted percentage dissatisfied. Thus, the study concludes the hybrid IEC-DEC-VCAC as an optimum configuration for building AC in Multan.


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