scholarly journals Identifying the critical orientation of wood-frame walls in assessing moisture risks using hygrothermal simulation

2021 ◽  
Vol 2069 (1) ◽  
pp. 012011
Author(s):  
Chetan Aggarwal ◽  
Maurice Defo ◽  
Hua Ge ◽  
Michael A Lacasse

Abstract Hygrothermal simulations can be used as a reliable tool in analysing moisture performance. For an efficient analysis, it is important to appropriately select the wall orientation in the simulations. ASHRAE 160 recommends to using orientation with highest amount of annual wind-driven rain (WDR) and the orientation with the least annual solar radiation. The objective of this work was to identify the orientation which leads to the worst moisture performance of different wall assemblies under historical climate in different Canadian cities. Four cardinal orientations (North, East, South, and West) and orientation receiving the highest amount of annual WDR (Default) were tested in this study. The simulations were carried out assuming three scenarios of moisture loads for four different wood-frame (2×6 wood stud) wall systems that differ by their claddings: brick, fibreboard, stucco, and vinyl. With an assumption of no WDR, north facing wall always leads to the worst moisture performance. In the presence of WDR, with and without water source, default orientation leads to the worst moisture performance with few exceptions. As default orientation was based on total sum of WDR, it sometimes may not lead to worst performance and hence hourly distribution of WDR should be taken into consideration.

2021 ◽  
pp. 174425912098876
Author(s):  
Maurice Defo ◽  
Michael Lacasse ◽  
Abdelaziz Laouadi

The objective of this work was to compare the hygrothermal responses and the moisture performance of four wood-frame walls as predicted by four hygrothermal (HAM) simulation tools, namely: DELPHIN, WUFI, hygIRC and COMSOL. The four wall systems differ only in their cladding type; these were fibreboard, vinyl, stucco and brick. Three Canadian cities having different climates were selected for simulations: Ottawa, Ontario; Vancouver, British Columbia and Calgary, Alberta. In each city, simulations were run for 2 years. Temperature and relative humidity of the outer layer of OSB sheathing were compared amongst the four simulation tools. The mould growth index on the outer layer of the OSB sheathing was used to compare the moisture performance predicted by the respective hygrothermal simulation tools. Temperature profiles of the outer layer of the OSB sheathing were all in good agreement for the four HAM tools in the three locations. For relative humidity, the highest discrepancies amongst the four tools were found with stucco cladding where differences as high as 20% could be found from time to time. Mould growth indices predicted by the four HAM tools were similar in some cases but different in other cases. The discrepancies amongst the different HAM tools were likely related to: the material property processing, how the quantity of wind-driven rain absorbed at the cladding surface is computed and some implementation details. Despite these discrepancies, The tools generally yielded consistent results and could be used for comparing the impacts of different designs on the risk of premature deterioration, as well as for evaluating the relative effects of climate change on a given wall assembly design.


2015 ◽  
Vol 6 (2) ◽  
pp. 111-127
Author(s):  
K. Tiwana ◽  
P. Mukhopadhyaya ◽  
E. Zalok ◽  
D. Van Reenen ◽  
C. Copeland ◽  
...  

This paper discusses the results of a research project which aimed at determining the hygrothermal (i.e. thermal and moisture) performance of the Canadian wood-frame building envelope construction in the city of Shanghai in China. The performance assessments of the wood-frame walls were conducted using the two-dimensional hygrothermal simulation tool called hygIRC-2D. In this study an in-fill type wall was considered and hygrothermal simulations were carried out for the weather conditions of Shanghai. Investigations were conducted to determine the influence of the vapour barrier, exterior stucco cladding material and different types of sheathing boards on the moisture performance of in-fill walls. Additional simulations were carried out to determine the influence of air leakage on the moisture performance of in-fill walls. The outputs from the simulations were analysed with the help of a hygrothermal response indicator called RHT index. It was concluded that the design of the in-fill wall including a rain screen but omitting a vapour barrier is expected to lead to the maximum reduction in hygrothermal loading when exposed to the weather conditions of Shanghai, China.


Author(s):  
V. V. Satyamurty ◽  
P. Ravikumar

It has been found that the values of ratio of hourly diffuse illuminance to daily diffuse illuminance, rvd, are very close to the corresponding values for diffuse solar radiation, rd, examined from the measured data of two locations. This has been further confirmed by examining the values for rvd and rd as calculated from TMY2 [1] data base for primary locations. Based on this, it has been proposed that the correlations available in literature to predict rd can be employed to predict rvd Adequacy of the correlation due to Satyamurty and Lahiri [2] available for rd has been examined to predict rvd as obtained from TMY2 data base for the 56 primary locations. It has been found that the values of rvd obtained from measured illuminance data of two locations have been predicted within a rms difference of 7.1% and within a rms difference of 4.3% for the 56 primary locations of TMY2 data when the correlation due to Satyamurty and Lahiri for rd has been employed after suitable modification.


Buildings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 148
Author(s):  
Ming Lu ◽  
Yan Zhang ◽  
Jun Xing ◽  
Wenda Ma

With the development of energy-saving and emission-reduction, solar energy as a clean energy with excellent characteristics has bright prospects for development and application in residential environment with high energy consumption. With the intensification of land use, there are more and more high-rise residential areas in the city. If the residential construction becomes more compact, the solar radiation of the buildings will be in loss. Therefore, there may exist some restrictive relationship between the residential layout patterns and the solar radiation quantity. Through the multiple response frequency analysis method of SPSS, the study summarizes three typical high-rise residential layout patterns, which are parallel determinant, non-parallel determinant and three-sided enclosure. The Autodesk Ecotect is used to simulate the solar radiation quantity of each building roof and south facade. Last, obtain the relationship between the residential layout index and the solar radiation quantity. The results show that there actually exists certain correlativity between solar radiation quantity and floor area ratio, building density and building height; meanwhile, each annual solar radiation quantity changed by residential layout index has its own variable curve. The results also indicate that three-sided enclosure layout pattern has greater solar radiation potential than parallel determinant and non-parallel determinant. By summarizing the corresponding conclusions, the optimal mode of high-rise settlements with high solar radiation is explored, which can provide reference for further residential planning.


2020 ◽  
Vol 1008 ◽  
pp. 72-83
Author(s):  
Asmaa Mohammed Nageib ◽  
Abbas Mohamed El-Zafarany ◽  
Fatma Osman Mohamed ◽  
Mohamed Helmy El-Hefnawy

The office buildings in Egypt, especially in Upper Egypt, reflect serious problems in achieving for energy efficiency as a result of increasing the use of mechanical refrigeration devices in office rooms, due to solar radiation and rising summer temperatures in recent years. Smart windows can play an important role in reducing significantly the energy consumption and maintaining energy inside buildings, also helps to control incoming solar radiation in order to minimize solar gain, especially in summer as well as ensuring the best natural lighting conditions without glare inside a room. This paper aims to evaluate the most efficient daylight and thermal performance of various types of the smart glazing and its impact on the energy consumption in the climatic conditions of one of the office buildings (Diwan governorate) in Sohag governorate as one of Upper Egypt governorates, with determining the best smart glass types for efficient use of energy. The paper follows the theoretical, applied, by studying types of smart glazing and their relation to achieving the energy efficiency. Then using (Energy Plus) simulation tool, which has been used in utilizing its modeling orientation (Design Builder) to study using types of smart glazing on the model of an office room in Building of Diwan governorate of Sohag in the four different orientations (North, East, South and West), when window-to-floor ratios (WFRs) (8%, 16%, 24% and 32%). The paper ends with a presentation of the most important results, recommendations and determination the best types of smart glass that provides energy, daylight without glare and providing greater comfort to users.


2020 ◽  
Author(s):  
Eloisa Di Sipio ◽  
Raffaele Sassi ◽  
Stefano Buggiarin ◽  
Silvia Ceccato ◽  
Antonio Galgaro

<p>The utilization and development of renewable energy sources (RES) is currently a topic of great interest in energy field. In detail, the coupling of different RES and related technologies, as solar thermal and shallow geothermal, for heating/cooling purpose of residential buildings is a promising sector. The possibility to store the thermal energy produced by solar panels in the underground during the summer season, when the insolation is greater, and to use the heat accumulated during the coldest periods, is strictly related, among others, both to the thermo-physical properties of rocks and to the solar radiation locally available. As the ground is the invariant component of the whole system, a better knowledge of its thermal properties (i.e. thermal conductivity, volumetric heat capacity…) is fundamental to evaluate the amount of heat that can be stored.</p><p>This paper presents an innovative methodological approach combining information related to underground thermal energy exchanging and storage capacity with the solar radiation, taking also into account the location of the possible end-users, that is the distribution of the residential buildings in the territory. The Euganean Hills area, located in the Po River Plain (north-east Italy), is selected as demonstration test site. A qualitative map, created using Geographycal Information System (GIS) application, has been realized in order to represent the “Ground thermal suitability” of a territory to sensible heat storage, that is the possibility to store solar energy in the underground for a later use.</p><p>This thematic map is a really promising tool, suitable for local administrator and professionals, for planning the possible exploitation of solar thermal renewable resources available in the area.</p>


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Kacem Gairaa ◽  
Yahia Bakelli

Due to its geographical position in the solar belt, Algeria is blessed with an abundance of solar energy and has the opportunity to utilize this bounty of natural energy effectively, promoting a clean environment and developing renewable energy technologies in the region. This paper assesses and analyses the solar energy potential in Ghardaïa area (south Algeria) to help users for solar energy applications. A database of solar radiation components has been employed for this purpose. The data presented in the paper are compared with other data supplied by renowned regional and international establishments, such as the solar atlas for the Mediterranean and the NASA. The frequency and the hourly distribution of solar radiation components indicate that the region is considered as an economical area and favorable for solar applications, such as the photovoltaic and the concentrating solar power (CSP) technologies. In addition to solar radiation, data of two functions, namely, clearness index and sunshine fraction have been examined; their results specify that the site has a clear sky conditions in most time of the year. In general, the obtained results illustrate that the site under consideration can use solar energy as a promising solution to conventional energy.


1969 ◽  
Vol 20 ◽  
pp. 71-74 ◽  
Author(s):  
Tapani Tukiainen ◽  
Bjørn Thomassen

An airborne hyperspectral survey was organised by the Geological Survey of Denmark and Greenland (GEUS) and carried out in 2000 to test the use of spectral analysis in mineral exploration under Arctic conditions. The hyperspectral data were acquired by using the HyMap imaging system consisting of sensors that collect reflected solar radiation in 126 bands covering the 440–2500 nm wavelength range (Bedini & Tukiainen 2008). The spatial resolution was 4 × 4 m (Tukiainen 2001). Eight sites underlain by Caledonian or post-Caledonian rocks with known mineral occurrences (Fig. 1) were tested. The project was financially supported by the Greenland Bureau of Minerals and Petroleum and the data were analysed by GEUS. Here we provide a summary of the results.


2017 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Nwokolo Samuel Chukwujindu ◽  
Ogbulezie Julie C. ◽  
John-Jaja Sylvia Alwell

In this study, relationship between photosynthetically active radiation (PAR) and global solar radiation (H) over selected climatic zones in Nigeria using 22-years data (July 1983 – June 2005) was analysed. Empirical model was employed as the baseline for theoretical formulation and estimation of the ratio of PAR/H over climatic zones in Nigeria. From the estimated values, the seasonal PAR/H ranged from 1.946-2.005, 1.909-1.955, 1.968-2.039, 1.987-2.060, 1.961-2.041, 1.928-1.984 and 1.946-2.005 in rainy season, and the high values were due to low influence from clearness index, harmattan dust and pyrogenic aerosols from regional biomass burning compared with 1.906-1.923, 1.905-1.917, 1.927-1.952, 1.950-1.999, 1.971-1.985 and 1.889-1.923 recorded in dry season as a result of combined high influence from cloudiness, pyogenic aerosols and harmattan dust with annual mean values of 1.943, 1.921, 1.975, 2.007, 1.986 and 1.936 for Ilorin, Sokoto, Abeokuta, Port Harcourt, Enugu and Gusau respectively. The annual ratio of PAR/H revealed that there is an evidence increase of the values from North-East (Gusau) to South-South (Port Harcourt). These variations were mainly due to trends in cloudiness and associated atmospheric moisture with the movement of the Hadley cell circulation system along the equatorial line. From the analysed results, the model was found suitable and meteorologically reliable to estimate PAR/H accurately from commonly available H data when compared with results within and beyond tropical locations in Nigeria.


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