scholarly journals Assessment of the Thermal Performance of Vertical Green Walls Using Overall Thermal Transfer Value Based BIM Simulation Method: Case Study of Residential Buildings in Sub-Tropics

2021 ◽  
Vol 8 (2) ◽  
pp. 294-312
Author(s):  
Ali Ahmed Salem Bahdad ◽  
◽  
Sharifah Fairuz Syed Fadzil ◽  
Hilary Omatule Onubi ◽  
◽  
...  
Keyword(s):  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Residential Buildings ◽  
Simulation Method ◽  
Green Technology ◽  
Thermal Transfer ◽  
Building Information ◽  
Long Time ◽  
Building Cooling

Construction of multifunctional building envelopes using vertical greenery walls (VGW) has emerged as a sustainable green technology to improving cooling efficiency. To attaining the desired level of building cooling performance, VGW and overall thermal transfer value (OTTV) of the walls are useful design factors. The study aims to revise the current VGW evaluation, considering the decreased heat flux due to thermal efficiency of wall construction based on OTTV values. To achieve this, OTTV based Building Information Modelling (BIM) simulation method was proposed using Autodesk-Revit and DesignBuilder simulation based on EnergyPlus. Six wall compositions with various OTTV values of south facade for residential buildings located in sub-tropical in cooling season, were evaluated. The findings demonstrate that in the presence of a green system, a good OTTV value of the exterior walls is required for optimal performance, to keep the space within set point of cooling for long time during the cooling season. The comparisons between the bare walls and the VGW have demonstrated a great variation due to the different OTTV reached up to 6.57% and 18.44% reduction in indoor air temperature. The best combination of VGW resulted a maximum of 1.2°C reduction in indoor air temperature, with number of hours (within 28°C or less) were higher by 2506h, representing 85.59% of the overall number of hours (2928h). Overall cooling energy saving is found as 103.3kwh, representing 13.63% of the total of energy saving, and decreased the heat gained by 38.82%, representing 61.51kwh reduction during cooling season compared to base wall.

scholarly journals Microbiome in an Office Building Using a Cooling Trench as an Outdoor Air Duct

2019 ◽  
Vol 111 ◽  
pp. 06045
Author(s):  
Mizuki Niimura ◽  
U Yanagi
Keyword(s):  
Relative Humidity ◽  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Principal Coordinate Analysis ◽  
Office Building ◽  
Metagenomic Analysis ◽  
Outdoor Air ◽  
Energy Saving Technique ◽  
Building Cooling

Subterranean temperature at a depth of 10 m is almost equal to the average outdoor air temperature of the same area. Therefore, if a building cooling trench is used as an outdoor air duct, outdoor air can be cooled in summer and warmed in winter. This energy-saving technique is often used in Japan. However, since the relative humidity in a cooling trench is high, microbe numbers tend to increase in summer. The present study sought to characterize the microbiome status in the cooling trench of such an office building in Japan. Specifically, we performed a metagenomic analysis in which we analyzed DNA directly upon collection from the environment, without intervening cultivation. The results showed the presence of bacteria of the genera Pseudomonas, Lactobacillus, Nesterenkonia, Staphylococcus, Deinococcus, Acinetobacter, Enhydorobacter, and Corynebacterium. Bacteria of the genera Nesterenkonia, Deinococcus, Enhydorobacter, and Corynebacterium predominated on the surface of the trench. Notably, bacteria of the genus Nesterenkonia constituted >50% of the organisms on the surface of the downstream end of the cooling trench. Principal coordinate analysis was used to compare bacterial inhabitants of outdoor air, indoor air from 2nd- and 3rdfloor offices, and the region downstream of the cooling trench. The results suggested that the microbiome of air in this cooling trench influenced indoor air within the building.

scholarly journals Probabilistic modeling of the indoor climates of residential buildings using EnergyPlus

2017 ◽  
Vol 41 (3) ◽  
pp. 225-246 ◽  
Author(s):  
Elizabeth Buechler ◽  
Simon Pallin ◽  
Philip Boudreaux ◽  
Michaela Stockdale
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Indoor Air ◽  
Air Conditioning ◽  
Residential Buildings ◽  
The United States ◽  
Climate Data ◽  
Indoor Climate ◽  
Oak Ridge ◽  
Simulation Engine

The indoor air temperature and relative humidity in residential buildings significantly affect material moisture durability, heating, ventilation, and air-conditioning system performance, and occupant comfort. Therefore, indoor climate data are generally required to define boundary conditions in numerical models that evaluate envelope durability and equipment performance. However, indoor climate data obtained from field studies are influenced by weather, occupant behavior, and internal loads and are generally unrepresentative of the residential building stock. Likewise, whole-building simulation models typically neglect stochastic variables and yield deterministic results that are applicable to only a single home in a specific climate. The purpose of this study was to probabilistically model homes with the simulation engine EnergyPlus to generate indoor climate data that are widely applicable to residential buildings. Monte Carlo methods were used to perform 840,000 simulations on the Oak Ridge National Laboratory supercomputer (Titan) that accounted for stochastic variation in internal loads, air tightness, home size, and thermostat set points. The Effective Moisture Penetration Depth model was used to consider the effects of moisture buffering. The effects of location and building type on indoor climate were analyzed by evaluating six building types and 14 locations across the United States. The average monthly net indoor moisture supply values were calculated for each climate zone, and the distributions of indoor air temperature and relative humidity conditions were compared with ASHRAE 160 and EN 15026 design conditions. The indoor climate data will be incorporated into an online database tool to aid the building community in designing effective heating, ventilation, and air-conditioning systems and moisture durable building envelopes.

scholarly journals Theoretical Study on the Relationship of Building Thermal Insulation with Indoor Thermal Comfort Based on APMV Index and Energy Consumption of Rural Residential Buildings

2021 ◽  
Vol 11 (18) ◽  
pp. 8565
Author(s):  
Jinzhe Nie ◽  
Yuxin Pang ◽  
Congcong Wang ◽  
Han Zhang ◽  
Kuichao Yin
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Indoor Air ◽  
Residential Buildings ◽  
Field Investigation ◽  
Energy And Environment ◽  
Indoor Thermal Comfort ◽  
Adaptive Thermal Comfort ◽  
Insulation Thickness ◽  
The Relationship

In the field investigation of rural dwellings, it was found that thermal feelings are significantly different with varied envelopes even under the same indoor air temperature, and this paper explores the phenomenon in simulation. Based on building thermal investigations in several villages of North China, a typical energy and environment simulation model for rural residences was developed using DeST, and the hourly parameters of temperature and humidity were used to calculate the adaptive thermal comfort (APMV) of the rooms. The results show that the main reason for the different thermal comfort at the same air temperature is the large difference in the inner surface temperature. By adjusting the insulation thickness of the envelope structure, the relationship between it and the APMV value is obtained. By adjusting the insulation thickness of the enclosure structure and getting the correlation between it and the APMV value, it is obtained that when the heat transfer coefficient of the enclosure structure meets 0.5 W/ (m2−K), the indoors can be in thermal comfort. This paper considers that the indoor air temperature cannot represent the APMV to evaluate the indoor thermal comfort, and the APMV value should be used to evaluate the thermal comfort of the renovated building and calculate the corresponding energy saving rate.

Field Survey on Occupant Thermal Comfort of Cold Regions in Transition Season

2013 ◽  
Vol 805-806 ◽  
pp. 1620-1624 ◽  
Author(s):  
Wan Ying Qu
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Indoor Air ◽  
Field Survey ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Residential Buildings ◽  
Cold Regions ◽  
Indoor Thermal Environment ◽  
Transition Season

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.

Indoor air distribution in a room with underfloor air distribution and chilled ceiling: Effect of ceiling surface temperature and supply air velocity

2019 ◽  
Vol 29 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Jie Gao ◽  
Haichao Wang ◽  
Xiaozhou Wu ◽  
Fenghao Wang ◽  
Zhen Tian
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Indoor Air ◽  
Residential Buildings ◽  
Air Distribution ◽  
Cooling Load ◽  
Air Velocity ◽  
Underfloor Air Distribution ◽  
Chilled Ceiling ◽  
Cooling Loads

An underfloor air distribution (UFAD) system integrated with a chilled ceiling (CC) cooling system may be a potential advanced heating, ventilation and air conditioning system in modern non-residential buildings with high sensible cooling loads. This article presents an experimental study concerning the effect of ceiling surface temperature and supply air velocity on the indoor air distribution in a room with UFAD as the internal and external sensible cooling loads change. The vertical distributions of indoor air temperature, air velocity and contaminant (CO2) concentration were evaluated by vertical air temperature difference (VATD), turbulence intensity (TI) and contaminant removal effectiveness (CRE), respectively. The results showed that the average VATD, TI and CRE levels were 0.5°C–1.0°C, 31%–41% and 0.85–1.06 when both internal and external sensible cooling loads were 41.5 W/m2. These evaluation indices varied clearly when the external sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2, whereas they remained almost the same when the internal sensible cooling load increased from 41.5 W/m2 to 69.5 W/m2. The maximum TI coincided with the minimum CRE under the condition of a constant sensible cooling load. Moreover, an air diffusion performance index clearly reduced with an increase in the heat removal effectiveness. It is recommended that it is important to balance the indoor air quality and energy consumption in a room with UFAD + CC.

Study of Residential Energy-Saving Green Technology

2013 ◽  
Vol 446-447 ◽  
pp. 1552-1557
Author(s):  
Wei Cheng
Keyword(s):  
Energy Saving ◽  
Residential Buildings ◽  
Green Building ◽  
Green Technology ◽  
Appropriate Technology ◽  
Green Paper ◽  
High Tech ◽  
Housing Design ◽  
Ecological Principles ◽  
Outdoor Spaces

The green house is a green building technology in residential application of the specific embodiment .It is the use of ecological principles and following the principles of sustainable development, ecological balance that is to design, organize indoor and outdoor spaces in residential buildings of various material factors and create no pollution, ecological smooth the built environment. Ecological Housing characteristics summarize in four aspects, namely, comfortable, healthy, efficient and beautiful. The pursuit of comfort and health are the basis of ecological residence and the pursuit of efficiency is the core of ecological residence as well as the pursuit of beauty is in harmony with nature ecological house of perfection. At present, the construction market in the application of ecological and energy-saving technologies exist errors, green technology does not mean that the ecological high-tech and high cost. Green paper from the overall current situation of residential construction, and ecological building techniques are used in a variety of ecological and energy-saving technologies that were specific research in the "Ecological housing design," The profound basis of knowledge and research focusing on ecological housing should be adopted by the design principles of appropriate technology through the specific architectural practice. It summarizes the key on the actual project that should be considered and applied technology.

Design and Application of a Seasonal Solar Soil Heat Storage System Applied in Greenhouse Heating

2014 ◽  
Vol 672-674 ◽  
pp. 21-25
Author(s):  
Liang Zhang ◽  
Peng Xu ◽  
Jia Chen Mao ◽  
Xu Tang
Keyword(s):  
Solar Energy ◽  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Solar Collector ◽  
Heat Storage ◽  
Storage System ◽  
Control Subsystem ◽  
And Control ◽  
Design And Application

A seasonal solar soil heat storage (SSSHS) system applied in greenhouse heating has been designed and introduced. The system consists of solar collector subsystem, soil heat storage subsystem, greenhouse heating subsystem, hydronic subsystem and control subsystem. By applying soil heat storage, solar energy stored in the soil under the greenhouse can be transferred and utilized in winter to realize the utilization of cross-seasonal energy. TRNSYS is used to simulate the process and effect in the system of the solar energy collection and soil heat storage in Shanghai, and the simulation is calibrated to improve the precision of the TRNSYS model. When the indoor air temperature of the greenhouse is kept at 12°C throughout the year, the energy saving by using the SSSHS system in Shanghai can be 46.2kWh/(m2∙year).

scholarly journals Causes of Quality Failures in Building Energy Renovation Projects of Northern China: A Review and Empirical Study

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2442 ◽  
Author(s):  
Yuting Qi ◽  
Queena Qian ◽  
Frits Meijer ◽  
Henk Visscher
Keyword(s):  
Energy Saving ◽  
Time Pressure ◽  
Residential Buildings ◽  
Northern China ◽  
Building Energy ◽  
Project Managers ◽  
Chinese Government ◽  
Skilled Workers ◽  
Construction Companies ◽  
Building Information

Building energy renovations can effectively improve the environmental performance and energy sustainability of existing buildings. From 2007 onwards, the Chinese government has promoted energy-saving renovations of existing urban residential buildings. Nevertheless, various quality failures happen during the construction period in energy-saving renovation projects of residential buildings. Yet, the causes and their characters remain largely unknown. Through a literature review, this paper investigates the causes of quality failures. Validated through experts’ interviews, a total of 18 causes were identified in building energy renovation projects. These causes were analyzed from two main aspects: the importance of a cause (related to impact and frequency), and the level of effort required to address a cause (related to origin and scale), using both a questionnaire survey and a focus group. The results indicate that the critical causes of quality failures are working under high-cost and high-time pressure, adverse natural conditions, fraud of construction companies, incomplete construction site survey, poor checking procedures of supervisors, poor operational skilled workers, inadequate equipment performance, lack of experienced project managers, and incomplete building information in projects. The causes were classified as external and internal causes of building energy renovation projects. The outcome of this paper should aid policy makers and project coordinators to focus on critical causes of quality failures, and to develop effective actions and policy interventions to achieve successful renovation projects with high-quality performance.

Energy Saving Analysis on Solar Capillary Radiation Heating System

2013 ◽  
Vol 448-453 ◽  
pp. 2807-2814 ◽  
Author(s):  
Jin Shun Wu ◽  
Song Pan ◽  
Jun Wei ◽  
Hong Wei Liu ◽  
Yi Xuan Wei ◽  
...  
Keyword(s):  
Water Temperature ◽  
Energy Saving ◽  
Air Temperature ◽  
Indoor Air ◽  
Solar Collector ◽  
Experimental System ◽  
Heating System ◽  
Capillary Network ◽  
Water Volume ◽  
Low Grade

Radiation capillary used as air conditioning terminal lower the demand of heating water temperature. In additional, solar collectors could also supply amount of low grade energy for heating. Meanwhile, solar is a kind of renewable, sustainable and environment friendly energy. It will save a massive of conventional energy if make full use of solar for heating. In this paper, an experimental system made of solar collector, capillary network and pump was built up and tested. According to thermal load of experimental room, both solar collector area and capillary network area are calculated, and circulating water temperature was analyzed in detail. A summary is given about characteristics of heat storage and release of solar collector, indoor air temperature varying and amount of energy saving. The key factors affect efficiency of collector includes water volume, water temperature in tanker and indoor air temperature. The results show that the solar system can well meet the heating demand and the effect of energy saving is very significant compared to common heating system.

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