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

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.

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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

Journal of Daylighting ◽

10.15627/jd.2021.23 ◽

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.

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Comparative thermal performance of static sunshade and brick cavity wall for energy efficient building envelope in composite climate

Thermal Science ◽

10.2298/tsci1403925c ◽

2014 ◽

Vol 18 (3) ◽

pp. 925-934 ◽

Cited By ~ 5

Author(s):

Meghana Charde ◽

Sourabh Bhati ◽

Ayushman Kheterpal ◽

Rajiv Gupta

Keyword(s):

Energy Consumption ◽

Air Temperature ◽

Indoor Air ◽

Energy Efficient ◽

Building Envelope ◽

Combined Effect ◽

Cavity Wall ◽

Outdoor Air ◽

Reduce Energy Consumption ◽

Energy Efficient Building

Energy efficient building technologies can reduce energy consumption in buildings. In present paper effect of designed static sunshade, brick cavity wall with brick projections and their combined effect on indoor air temperature has been analyzed by constructing three test rooms each of habitable dimensions (3.0 m ? 4.0 m ? 3.0 m) and studying hourly temperatures on typical days for one month in summer and winter each. The three rooms have also been simulated using a software and the results have been compared with the experimental results. Designed static sunshade increased indoor air temperature in winter while proposed brick cavity wall with brick projections lowered it in summer. Combined effect of building elements lowered indoor air temperature in summer and increased it in winter as compared to outdoor air temperature. It is thus useful for energy conservation in buildings in composite climate.

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Probabilistic modeling of the indoor climates of residential buildings using EnergyPlus

Journal of Building Physics ◽

10.1177/1744259117701893 ◽

2017 ◽

Vol 41 (3) ◽

pp. 225-246 ◽

Cited By ~ 3

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.

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Indoor air quality of newly built low-energy preschools – Are chemical emissions reduced in houses with eco-labelled building materials?

Indoor and Built Environment ◽

10.1177/1420326x18792600 ◽

2018 ◽

Vol 28 (4) ◽

pp. 506-519 ◽

Cited By ~ 4

Author(s):

Josefin Persson ◽

Thanh Wang ◽

Jessika Hagberg

Keyword(s):

Air Quality ◽

Relative Humidity ◽

Indoor Air Quality ◽

Air Temperature ◽

Indoor Air ◽

Building Materials ◽

Ventilation System ◽

Sampling Period ◽

Low Energy ◽

Low Energy Buildings

The use of an airtight frame in low-energy buildings could increase the risk of health-related problems, such as allergies and sick building syndromes (SBS), associated with chemical emissions from building materials, especially if the ventilation system is not functioning properly. In this study, the indoor air quality (IAQ) was investigated in newly built low-energy and conventional preschools by monitoring the indoor air temperature, relative humidity, particle-size distribution and levels of carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde and total volatile organic compounds (TVOC). The thermal comfort was satisfactory in all preschools, with average indoor air temperature and a relative humidity at 21.4°C and 36%, respectively. The highest levels of TVOC (range: 130–1650 µg/m3 toluene equivalents) and formaldehyde (range: 1.9–28.8 µg/m3) occurred during the first sampling period associated with strong emissions from building materials. However, those preschools constructed with environmental friendly building materials (such as Swan Eco-label) had lower initial TVOC levels compared to those preschools constructed with conventional building materials. The IAQ and indoor chemical emissions were also strongly dependent on the functioning of the ventilation system. Preliminary risk assessment indicated that exposure to acrolein and crotonaldehyde might lead to respiratory-tract irritation among occupants.

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Characteristics of SARS-CoV-2 aerosol dispersion in indoor air: scoping review

Research Society and Development ◽

10.33448/rsd-v10i4.14300 ◽

2021 ◽

Vol 10 (4) ◽

pp. e44310414300

Author(s):

Anyele Albuquerque Lima ◽

Izabelly Carollynny Maciel Nunes ◽

José Leandro da Silva Duarte ◽

Lucas Meili ◽

Patricia de Carvalho Nagliate ◽

...

Keyword(s):

Viral Load ◽

Relative Humidity ◽

Air Temperature ◽

Indoor Air ◽

Scoping Review ◽

Grey Literature ◽

Flow Diagram ◽

Minimum Size ◽

Management Tool ◽

Cochrane Library

Background: SARS-CoV-2 is the infectious agent responsible for COVID-19, its transmission occurs through the release of respiratory droplets and aerosols. Aim: Identify the main characteristics of SARS-CoV-2 aerosols dispersion in indoor air. Methods: Scoping Review was conducted using the databases: National Library of Medicines – MEDLINE/Pubmed, Scopus, Web of Science, Virtual Health Library (VHL) and Cochrane Library, the search in gray literature was performed on Google Scholar, OpenGrey and Grey Literature Report, from March to September 2020. The descriptors used were "coronavirus" and "aerosol". Data were selected and screened following the protocol established by the The Joanna Briggs Institute, PRISMA flow diagram and EndNote reference management tool. Findings: Ten papers were selected, which presented characteristics that could influence the SARS-CoV-2 aerosols dispersion, with highlight to: aerosol origin; viral load identified in the air (2.86 copies/liter of air); aerosol particle size with viral load (0.25 μm); dispersion (10.00 m); air stay time (3 h); influence of air temperature and relative humidity. Conclusion: Aerosol particles containing SARS-CoV-2 may have infectious viral charge, presenting a minimum size up to 0.25 μm, being able to reach up to 10 m of distance and survive in the air for a few hours. The variables air temperature and relative humidity did not present consistent evidence to influence the dispersion of SARS-CoV-2 aerosols.

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Influence of indoor air temperature and relative humidity on learning performance of undergraduates

Case Studies in Thermal Engineering ◽

10.1016/j.csite.2021.101458 ◽

2021 ◽

pp. 101458

Author(s):

Chao Liu ◽

Yalin Zhang ◽

Limei Sun ◽

Weijun Gao ◽

Xiaotong Jing ◽

...

Keyword(s):

Relative Humidity ◽

Air Temperature ◽

Indoor Air ◽

Learning Performance

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Cooling and Energy-Saving Performance of Different Green Wall Design: A Simulation Study of a Block

Energies ◽

10.3390/en12152912 ◽

2019 ◽

Vol 12 (15) ◽

pp. 2912 ◽

Cited By ~ 1

Author(s):

Jiayu Li ◽

Bohong Zheng ◽

Wenquan Shen ◽

Yanfen Xiang ◽

Xiao Chen ◽

...

Keyword(s):

Surface Temperature ◽

Energy Saving ◽

Air Temperature ◽

Cooling Power ◽

Wall Surface ◽

Low Carbon ◽

Outdoor Air ◽

Green Wall ◽

Green Walls ◽

Wall Surface Temperature

To mitigate the urban heat island (UHI) and release the low carbon potential of green walls, we analyzed the cooling and energy-saving performance of different green wall designs. Envi-met was applied as the main simulation tool, and a pedestrian street named Yuhou Street was selected as the study object. Four designs of walls were summarized and simulated, demonstrating the living wall system (LWS). Super soil had superiority in cooling and energy saving. Outdoor air temperature, indoor air temperature, outside wall surface temperature, and inside wall surface temperature were analyzed. Apart from the outdoor air temperature, the other three temperatures were all significantly affected by the design of green walls. Finally, energy savings in building cavities were determined. The indoor energy saving ratio of the LWS based on super soil reached 19.92%, followed by the LWS based on boxes at 15.37%, and green facades wall at 6.29%. The indoor cooling powers on this typical day showed that the cooling power of the LWS based on super soil was 8267.32 W, followed by the LWS based on boxes at 6381.57 W, and green facades wall at 2610.08 W. The results revealed the difference in cooling and energy-saving performance of different green walls in this typical hot summer area.

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Influence of detailing the climate model on the calculation of energy consumption

E3S Web of Conferences ◽

10.1051/e3sconf/202016402008 ◽

2020 ◽

Vol 164 ◽

pp. 02008

Author(s):

Elena Malyavina ◽

Olga Malikova ◽

Luong Van Pham

Keyword(s):

Energy Consumption ◽

Relative Humidity ◽

Air Temperature ◽

Climate Model ◽

Cooling System ◽

Climatic Data ◽

Outdoor Air ◽

Direct Measurements ◽

Air Conditioning Systems ◽

Parameter Values

The repeatability of outdoor air temperature and enthalpy combinations in a construction area is a necessary initial information for calculating the energy consumption of air conditioning systems. The most convenient form of presenting climatic data in such calculations is the probabilistic-statistical model, which constitutes a Table, the cells of which show the probabilistic repeatability of the outdoor air temperature and relative humidity. The parameter values given on the vertical and horizontal scales, that form the cell boundaries, can be taken with larger or smaller increments. The paper that served as the basis for this article, provides verification of the initial climatic model detailing experimentally under full-scale conditions in the city of Hanoi (Vietnam). The criterion for the appropriate model detailing was the deviation of the energy consumption estimates of the room cooling system, got experimentally and by calculation. Moreover, the calculations were performed not only on two climate probabilistic and statistical models, but also on the data of direct measurements of the outdoor air temperature and relative humidity with an accuracy of 0.1 for temperature and up to 2 % for relative humidity.

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Thermal comfort analysis of radiant cooling panels with dedicated fresh-air system

Indoor and Built Environment ◽

10.1177/1420326x20961142 ◽

2020 ◽

pp. 1420326X2096114

Author(s):

S. Y. Qin ◽

X. Cui ◽

C. Yang ◽

L. W. Jin

Keyword(s):

Relative Humidity ◽

Surface Temperature ◽

Thermal Comfort ◽

Air Temperature ◽

Indoor Air ◽

Area Ratio ◽

Human Thermal Comfort ◽

Air Supply ◽

Radiant Cooling ◽

Air System

Radiant system has been increasingly applied in buildings due to its good thermal comfort and energy-saving potential. In this research, a simplified predicted mean vote (PMV) model and sensible cooling load equation were proposed based on human thermal comfort. Simulations were carried out using Airpak to explore relationships among thermal comfort characteristics, design and operation parameters. Results show that radiant surface temperature, fresh-air supply temperature and the area ratio are correlated approximately linearly with the indoor air temperature, while the relative humidity has little effect on the indoor air temperature. The indoor air velocity in the simulated environment was no more than 0.15 m/s, satisfying the requirements of limit values in the occupied zone. The results indicate that the optimum radiant surface temperature ( tc) is 19°C to 23°C when fresh-air supply temperature ( ts) is 26°C. The relative humidity ( φ) should be maintained at 50% to 70%, and the area ratio of radiant panels to total surfaces ( k1) should be kept within 0.15 to 0.38 when the radiant surface temperature is 20°C and the fresh-air supply temperature is 26°C. The simplified PMV model and the sensible load equation can provide reference for panel design based on characteristics of radiant cooling panels with a dedicated fresh-air system.

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Indoor Daylighting and Thermal Response of a Passive Solar Building to Selective Components of Solar Radiation

Buildings ◽

10.3390/buildings11010034 ◽

2021 ◽

Vol 11 (1) ◽

pp. 34

Author(s):

Ochuko Kelvin Overen ◽

Edson Leroy Meyer ◽

Golden Makaka

Keyword(s):

Relative Humidity ◽

Solar Radiation ◽

Air Temperature ◽

Indoor Air ◽

Temperature Response ◽

Longwave Radiation ◽

Thermal Conditions ◽

Visible Radiation ◽

Downward Longwave Radiation ◽

Passive Solar

Solar radiation provides the most significant natural energy in buildings for space heating and daylighting. Due to atmospheric interference, solar radiation received at the Earth’s surface consists of direct beam and diffuse radiation, where diffuse can be further broken down into longwave and visible radiation. Although each of these components co-occurs, their influence on the indoor visual and thermal conditions of a building differ. This study aims to analyze the influence of the various components of solar radiation on the indoor thermal and daylighting of a passive solar building. Thus, a pyrheliometer, pyranometer, shaded-pyranometer, and pyrgeometer mounted on a SOLYS 2 (Kipp & Zonen, Delft, Netherlands) dual Axis sun tracker, were used to monitor direct, global horizontal, diffuse and downward longwave radiation, respectively. The seasonal indoor air temperature and relative humidity were measured using an HMP 60 temperature relative humidity probe. A Li-210R photometric sensor was used to monitor the indoor illuminance. The summer and winter indoor air temperature, as well as relative humidity, were found to be influenced by diffuse horizontal and global horizontal irradiance, respectively. In summer, the indoor air temperature response to diffuse horizontal irradiance was 0.7 °C/ħW/m2 and 1.1 °C/ħW/m2 to global horizontal irradiance in winter, where ħ is 99.9 W/m2. The indoor daylighting which was found to be above the minimum office visual task recommendation in most countries, but within the useful daylight illuminance range was dominated by direct normal irradiance. A response of 260 lux/ħW/m2 was observed. The findings of the study support the strategic locating of the windows in passive solar design. However, the results show that north-facing clerestory windows without shading device could lead to visual discomfort.

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