scholarly journals A simple heat and moisture transfer model to predict ground temperature for shallow ground heat exchangers

2017 ◽  
Vol 103 ◽  
pp. 295-307 ◽  
Author(s):  
Maha Chalhoub ◽  
Michel Bernier ◽  
Yves Coquet ◽  
Mikael Philippe
Keyword(s):  
Heat Exchangers ◽  
Moisture Transfer ◽  
Ground Temperature ◽  
Transfer Model ◽  
Heat And Moisture Transfer ◽  
Ground Heat Exchangers ◽  
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.

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.

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 Simplified two-step, cross-sectional approach for coupled heat and moisture transfer modeling of shallow, horizontal, ground-based heat Exchangers

2020 ◽  
Vol 205 ◽  
pp. 07004
Author(s):  
Hyunjun Oh ◽  
James M. Tinjum
Keyword(s):  
Heat Exchangers ◽  
Moisture Transfer ◽  
Environmental Control ◽  
Meteorological Data ◽  
Fluid Temperature ◽  
Heat And Moisture Transfer ◽  
Cross Sectional ◽  
Ambient Temperatures ◽  
Coupled Heat And Moisture ◽  
Heat And Moisture

This study evaluates a two-step, cross-sectional approach for designing shallow, unsaturated, horizontal, ground-based heat exchangers (GHXs). Numerical modeling was conducted for coupled heat and moisture transfer around GHXs under transient climatological conditions through a cooling season. Soil samples were collected in Texas and Wisconsin to measure thermal conductivity dry-out curves and soil-water characteristic curves for use in the modeling. Average daily meteorological data from central Texas was applied for the top boundary condition. Heat generation from the GHX was calculated by total condenser heat rejection from an environmental control unit based on ambient temperatures and unit specifications. In the first step of the modeling, results showed that the fluid temperature through the GHX loop was approximately 43 ºC, and rapid heat and moisture fluxes were observed around the GHX loops. High moisture flux along the upper surface was also observed due to high ambient temperatures that occur during the summer season. Using these results, exiting temperature of the GHX was estimated for the second cross-sectional modeling step. This two-step, cross-sectional modeling approach provides a systematic analysis of coupled heat and moisture transfer around shallow, horizontal, unsaturated GHX loops, thus simplifying high computational effort needed for full three-dimensional modeling of shallow GHX systems.

Heat and moisture transfer performance of thin cotton fabric under impingement drying

2018 ◽  
Vol 89 (15) ◽  
pp. 3089-3097
Author(s):  
Miao Qian ◽  
Jinghan Wang ◽  
Zhong Xiang ◽  
Zhewei Zhao ◽  
Xudong Hu
Keyword(s):  
Moisture Content ◽  
Cotton Fabric ◽  
Moisture Transfer ◽  
Transfer Model ◽  
Transfer Performance ◽  
Heat And Moisture Transfer ◽  
Drying Time ◽  
Uniform Distributions ◽  
Heat And Moisture ◽  
Over Time

To investigate the drying characteristics of thin cotton fabric for reducing the energy consumption during the heat setting process, a two-dimensional heat and moisture transfer model considering lateral heat and moisture transmission under the impingement drying condition was developed in this study. The curves of the variation in fabric temperature and moisture content over time were obtained and the results indicate that the drying rate increases with the decrease in the moisture content in the fabric. In addition, non-uniform distributions of temperature and moisture on the fabric over time were obtained. The drying time per unit area on the fabric was found to increase with time. Further, experiments were conducted to test the heat and moisture transfer performance of the fabric, and the experimental results agree reasonably well with the calculations.

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