scholarly journals Application Method of a Simplified Heat and Moisture Transfer Model of Building Construction in Residential Buildings

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4180
Author(s):  
Joowook Kim ◽  
Michael Brandemuehl
Keyword(s):  
Latent Heat ◽  
Moisture Transfer ◽  
Residential Buildings ◽  
Building Energy ◽  
The United States ◽  
Building Envelope ◽  
Outdoor Environment ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Several building energy simulation programs have been developed to evaluate the indoor conditions and energy performance of buildings. As a fundamental component of heating, ventilating, and air conditioning loads, each building energy modeling tool calculates the heat and moisture exchange among the outdoor environment, building envelope, and indoor environments. This paper presents a simplified heat and moisture transfer model of the building envelope, and case studies for building performance obtained by different heat and moisture transfer models are conducted to investigate the contribution of the proposed steady-state moisture flux (SSMF) method. For the analysis, three representative humid locations in the United States are considered: Miami, Atlanta, and Chicago. The results show that the SSMF model effectively complements the latent heat transfer calculation in conduction transfer function (CTF) and effective moisture penetration depth (EMPD) models during the cooling season. In addition, it is found that the ceiling part of a building largely constitutes the latent heat generated by the SSMF model.

Development of a numerical approach to assess the effect of coupled heat and moisture transfer on energy consumption of residential buildings in Moroccan context

2021 ◽  
pp. 174425912110560
Author(s):  
Yassine Chbani Idrissi ◽  
Rafik Belarbi ◽  
Mohammed Yacine Ferroukhi ◽  
M’barek Feddaoui ◽  
Driss Agliz
Keyword(s):  
Energy Consumption ◽  
Building Materials ◽  
Moisture Transfer ◽  
Residential Buildings ◽  
Building Design ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Heat And Moisture Transfer ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

Hygrothermal properties of building materials, climatic conditions and energy performance are interrelated and have to be considered simultaneously as part of an optimised building design. In this paper, a new approach to evaluate the energy consumption of residential buildings in Morocco is presented. This approach is based on the effect of coupled heat and moisture transfer in typical residential buildings and on their responses to the varied climatic conditions encountered in the country. This approach allows us to evaluate with better accuracy the response of building energy performance and the indoor comfort of building occupants. Annual energy consumption, cooling and heating energy requirements were estimated considering the six climatic zones of Morocco. Based on the results, terms related to coupled heat and moisture transfer can effectively correct the existing energy consumption calculations of the six zones of Morocco, which currently do not consider energy consumption due to coupled heat and moisture transfer.

Ground-Coupled Heat and Moisture Transfer From Buildings: Part 1 — Analysis and Modeling

2001 ◽  
Author(s):  
Michael P. Deru ◽  
Allan T. Kirkpatrick
Keyword(s):  
Moisture Transfer ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Ground Temperatures ◽  
Heat Effects ◽  
Tightly Coupled ◽  
Finite Element Procedure ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture ◽  
Properties Of Soil

Abstract Ground-heat transfer is tightly coupled with soil-moisture transfer. The coupling is threefold: heat is transferred by thermal conduction and by moisture transfer; the thermal properties of soil are strong functions of the moisture content; and moisture phase change includes latent heat effects and changes in thermal and hydraulic properties. A heat and moisture transfer model was developed to study the ground-coupled heat and moisture transfer from buildings. The model also includes detailed considerations of the atmospheric boundary conditions, including precipitation. Solutions for the soil temperature distribution are obtained using a finite element procedure. The model compared well with the seasonal variation of measured ground temperatures.

scholarly journals Modification of building energy simulation tool TRNSYS for modelling nonlinear heat and moisture transfer phenomena by TRNSYS/MATLAB integration

2020 ◽  
Vol 172 ◽  
pp. 25009
Author(s):  
Ajaya Ketan Nayak ◽  
Aya Hagishima
Keyword(s):  
Numerical Simulation ◽  
Moisture Transfer ◽  
Ambient Air ◽  
Building Energy ◽  
Energy Simulation ◽  
Modular Structure ◽  
Integration Scheme ◽  
Building Energy Simulation ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

Software for numerical simulation of various types of energy used in buildings, i.e. building energy simulation (BES), have become an essential tool for recent research pertaining to building physics. TRNSYS is a well-known BES used in both academia and the construction industry for a wide range of simulations, such as the design and performance evaluation of buildings and related facilities for heating, cooling, and ventilation. TRNSYS has a modular structure comprising various components, and each component is interconnected and compiled through a common interface using a FORTRAN compiler. Its modular structure enables interactions with various external numerical simulation tools, such as MATLAB, Python, and ESP-r. For ordinary simulations of building energy load using TRNSYS, the generic module Type 56 is usually recommended, which provides detailed physics modelling of building thermal behaviours based on unsteady energy conservation equations and Fourier’s law for each building material. However, Type 56 explicitly depends on the transfer function method to discretise the original differential equations; therefore, it cannot model nonlinear phenomena, such as latent heat and moisture transfer between a building surface and ambient air. In other words, the current TRNSYS cannot be used to estimate the effectiveness of evaporation during cooling, which is a typical passive design method. Hence, the authors developed a MATLAB/TRNSYS integration scheme, in which TRNSYS was modified to model simultaneous heat and moisture transfer from the wet roof surface of a building. This scheme enabled TRNSYS to calculate the rate of evaporative heat and moisture transfer dynamically from the roof surface, assuming a control volume approximation of the roof surface. Finally, the effect of evaporative cooling on the thermal performance of an Indian building was estimated using the modified model.

scholarly journals Numerical Simulation of Phase Change Material Composite Wallboard in a Multi-Layered Building Envelope

2012 ◽  
Author(s):  
Stephen D. Zwanzig ◽  
Yongsheng Lian ◽  
Ellen G. Brehob
Keyword(s):  
Energy Consumption ◽  
Boundary Conditions ◽  
Phase Change ◽  
Latent Heat ◽  
Residential Buildings ◽  
Peak Load ◽  
The United States ◽  
Building Envelope ◽  
Latent Heat Storage ◽  
Exterior Boundary

Residential buildings account for a large portion of total energy consumption in the United States. Residential energy usage can be dramatically reduced by improving the efficiency of building envelope systems. One such method is to incorporate thermally massive construction materials into the building envelope. This benefits building operation by reducing the energy requirement for maintaining thermal comfort, downsizing the AC/heating equipment, and shifting the peak load from the electrical grid. When impregnated or encapsulated into wallboard or concrete systems, phase change materials (PCMs) can greatly enhance their thermal energy storage capacity and effective thermal mass. In this work we numerically study the potential of PCM on energy saving for residential homes. For that purpose we solve the one-dimensional, transient heat equation through the multi-layered building envelope using the Crank-Nicolson discretization scheme. The latent heat storage of the PCM was accounted for with a phase fraction in a latent heat source term. Using this code we examine a PCM composite wallboard incorporated into the walls and roof of a typical residential building across various climate zones. The PCM performance was studied under all seasonal conditions using the latest typical meteorological year (TMY3) data for exterior boundary conditions. Comparisons were made between different PCM wallboard locations. Our work shows that there is an optimized location for PCM placement within building envelope surfaces dependent upon the resistance values between the PCM layer and the exterior boundary conditions. We further identified the energy savings potential by comparing the performance of the PCM wallboard against the performance of a building envelope without PCM. Our study shows that PCM composite wallboard can reduce the energy consumption in summer and winter and can shift the peak electricity load in the summer.

Development of experimental study on coupled heat and moisture transfer in porous building envelope

2012 ◽  
Vol 19 (3) ◽  
pp. 669-674 ◽  
Author(s):  
Guo-jie Chen ◽  
Xiang-wei Liu ◽  
You-ming Chen ◽  
Xing-guo Guo ◽  
Yong-qiang Deng
Keyword(s):  
Experimental Study ◽  
Moisture Transfer ◽  
Building Envelope ◽  
Heat And Moisture Transfer ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

Ground-Coupled Heat and Moisture Transfer from Buildings Part 1–Analysis and Modeling*

2001 ◽  
Vol 124 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Michael P. Deru ◽  
Allan T. Kirkpatrick
Keyword(s):  
Moisture Transfer ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Ground Temperatures ◽  
Heat Effects ◽  
Tightly Coupled ◽  
Finite Element Procedure ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture ◽  
Properties Of Soil

Ground-heat transfer is tightly coupled with soil-moisture transfer. The coupling is threefold: heat is transferred by thermal conduction and by moisture transfer; the thermal properties of soil are strong functions of the moisture content; and moisture phase change includes latent heat effects and changes in thermal and hydraulic properties. A heat and moisture transfer model was developed to study the ground-coupled heat and moisture transfer from buildings. The model also includes detailed considerations of the atmospheric boundary conditions, including precipitation. Solutions for the soil temperature distribution are obtained using a finite element procedure. The model compared well with the seasonal variation of measured ground temperatures.

scholarly journals Simulation Research on the Effect of Coupled Heat and Moisture Transfer on the Energy Consumption and Indoor Environment of Public Buildings

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 141 ◽  
Author(s):  
Shui Yu ◽  
Yumeng Cui ◽  
Yifei Shao ◽  
Fuhong Han
Keyword(s):  
Energy Consumption ◽  
Indoor Environment ◽  
Moisture Transfer ◽  
Building Envelope ◽  
Thermal Calculation ◽  
Heat And Moisture Transfer ◽  
Building Envelopes ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture ◽  
Humidity Environment

A building envelope is a multi-layer porous structure. It transfers heat and moisture to balance the indoor and outdoor temperature difference and water vapor partial pressure difference. This is a typical coupled heat and moisture migration process. When the space is filled with moist air, water or ice, it will directly affect the thermal properties of the material. With respect to moisture coming through the wall into the indoor building, it will also affect the indoor environment and the energy consumption due to the formation of latent heat. However, the moisture transfer process in the building envelopes is not taken into account in the current conventional thermal calculation and energy consumption analysis. This paper analyzes the indoor thermal and humidity environment and building energy consumption of typical cities in Harbin, Shenyang, Beijing, Shanghai, and Guangzhou. The results show that it is obvious that the coupled heat and moisture transfer in the building envelopes has an impact on the annual cooling and heating energy consumption, the total energy consumption, and the indoor thermal and humidity environment. The geographical location of buildings ranging from north to south influences the effect of coupled heat and moisture transfer on the annual energy consumption of the building, moving from positive to negative. It is suggested that the additional coefficient of the coupled thermal and moisture method can effectively correct the existing energy consumption calculation results, which do not take the consumption from the coupled heat and moisture in the building envelopes into account.

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