The combined effect of heat and moisture transfer dependent thermal conductivity of polystyrene insulation material: Impact on building energy performance

2018 ◽  
Vol 169 ◽  
pp. 228-235 ◽  
Author(s):  
Maatouk Khoukhi
Keyword(s):  
Thermal Conductivity ◽  
Moisture Transfer ◽  
Building Energy ◽  
Energy Performance ◽  
Combined Effect ◽  
Insulation Material ◽  
Heat And Moisture Transfer ◽  
Building Energy Performance ◽  
Heat And Moisture

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.

Simultaneous determination of thickness, thermal conductivity and porosity in textile material design

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Dinghua Xu ◽  
Peng Cui
Keyword(s):  
Thermal Conductivity ◽  
Human Body ◽  
Moisture Transfer ◽  
Least Squares Method ◽  
Weighted Least Squares ◽  
Optimal Solution ◽  
Comfort Level ◽  
Textile Material ◽  
Heat And Moisture Transfer ◽  
Heat And Moisture

AbstractThe thickness, thermal conductivity and porosity of textile material are three key factors which determine the heat-moisture comfort level of the human body to a large extent based on the heat and moisture transfer process in the human body-clothing-environment system. This paper puts forward an Inverse Problem of Textile Thickness-Heat conductivity-Porosity Determination (IPT(THP)D) based on the steady-state model of heat and moisture transfer and the heat-moisture comfort indexes. Adopting the idea of the weighted least-squares method, we formulate IPT(THP)D into a function minimization problem. We employ the Particle Swarm Optimization (PSO) method to stochastically search the optimal solution of the objective function. We put the optimal solution into the corresponding direct problem to verify the effectiveness of the proposed numerical algorithms and the validity of the IPT(THP)D.

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.

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.

Analysis of Heat and Moisture Transfer Beneath Freezer Foundations-Part II

2004 ◽  
Vol 126 (2) ◽  
pp. 726-731 ◽  
Author(s):  
Moncef Krarti ◽  
Pirawas Chuangchid ◽  
Pyeongchan Ihm
Keyword(s):  
Thermal Conductivity ◽  
Heat Conduction ◽  
Numerical Solution ◽  
Moisture Transfer ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Soil Thermal Conductivity ◽  
Heat And Moisture Transfer ◽  
Conduction Model ◽  
Heat And Moisture

This paper discusses selected results from a numerical solution of two-dimensional heat and moisture transfer within frozen and unfrozen soils beneath freezer slab foundations. In particular, the numerical solution is used to determine soil temperature profiles as well as freezer foundation heat gains. Finally, an effective soil thermal conductivity is successfully utilized in a pure heat conduction model to predict ground-coupled heat gains for freezers.

The Analysis of Coupled Heat and Moisture Transfer in Building Envelop Based on Numerical Simulation

2012 ◽  
Vol 450-451 ◽  
pp. 1471-1476
Author(s):  
Shui Yu ◽  
Xu Zhang
Keyword(s):  
Building Materials ◽  
Moisture Transfer ◽  
Capillary Condensation ◽  
Building Energy ◽  
Environment Impact ◽  
Heat And Moisture Transfer ◽  
Common Structure ◽  
Building Envelop ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

The research of coupled heat and moisture transfer is a complex process, which is the fundamental of decreasing building energy consumption; improving IAQ and increasing the durability of building envelop. CHAMPS-BES software is an outcome of a joint effort between Building Energy and Environmental Systems Laboratory (BEESL) and Institute for Building Climatology (IBK). This software is used for analysis and prediction of hygrothermal performance of building enclosures; impact of outdoor climate and pollution on indoor environment; impact of VOC emissions from building materials and indoor furnishings on indoor air quality. This paper introduces the basic mathematic and physic model, boundary condition, climate condition etc, and analyzes the coupled heat and moisture transfer through common structure of building envelop in Shanghai. According to simulation results, main materials of the wall in ITIS have to endure larger range of temperature than ETIS that leads to the life of materials shorter. Capillary condensation occurs on inside surface of the wall easily when RH is larger than 70% and the minimum pore size of finish layer is around 5×10-9m avoiding capillary condensation and mold growth

A Model for Assessment of Heat and Moisture Transfer Hollow a Hemp Concerte Wall Using Finite Element Method

2022 ◽  
Author(s):  
Salah Ouldboukhitine ◽  
Sofiane Amziane ◽  
Maroua Benkhaled
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Energy Consumption ◽  
Moisture Transfer ◽  
Energy Performance ◽  
Vapor Permeability ◽  
Heat And Moisture Transfer ◽  
Concrete Wall ◽  
Heat And Moisture ◽  
Element Method

The energy performance of buildings represents a major challenge in terms of sustainable development. The buildings and buildings construction sectors combined are responsible for over one-third of global final energy consumption and nearly 40% of total direct and indirect CO2 emissions. In order to reduce the energy consumption of buildings and their harmful impact on the environment, special attention has been paid in recent years to the use of bio-based materials. In the present paper, a model of heat and moisture transfer hollow hemp concrete wall is proposed using finite element method. The energy and mass balances are expressed using measurable transfer drivers as temperature water content and vapor pressure and coefficients related explicitly to the macroscopic properties of material as thermal conductivity, specific heat, and water vapor permeability. The proposed model is implemented in MATLAB code and validated through experimental measurements.

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