The Effects of Thermal Mass and Phase Change Material on a Buildings’ Thermal Load

2009 ◽  
Author(s):  
Robert B. Gilbert
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Thermal Load ◽  
Thermal Mass ◽  
Load Reduction ◽  
Difference Model ◽  
Maximum Reduction ◽  
Material Equations ◽  
Change Material ◽  
Sinusoidal Function

A finite-difference model is used to simulate the effects of thermal mass and phase change material on thermal transmission through a building’s envelope wall. The exterior temperature is simulated by a sinusoidal function. The inside temperature is held constant. A comparison is given between the effects of thermal mass and phase change material. The maximum reduction in thermal load and required conditions is given for both thermal mass and phase change material. Equations are given for the maximum thermal load reduction as a function of the inside and outside temperature. Equations are also given which treat the thermal mass as a lumped capacitance and the expected error as a function of the amount of thermal mass. The conditions under which the addition of thermal mass and/or phase change material will result in a reduction of thermal load is given.

The Effect of Thermal Mass on Thermal Transmission Loads

2007 ◽  
Author(s):  
Robert B. Gilbert ◽  
Kelly Kissock
Keyword(s):  
Air Temperature ◽  
Thermal Load ◽  
Weather Conditions ◽  
Weather Data ◽  
Thermal Mass ◽  
Load Reduction ◽  
Difference Model ◽  
Data Files ◽  
The Mean ◽  
Sinusoidal Function

A finite-difference model is used to simulate the effects of thermal mass on thermal load. A sinusoidal function is used to simulate the exterior air temperature. The interior air temperature set point remains constant. The mechanism by which thermal mass affects thermal load is described. Equations are given to calculate thermal load as a function of the exterior air temperature amplitude, the temperature above and below the mean temperature. Equations are given to calculate the minimum thermal load resulting from thermal mass and therefore the maximum thermal load reduction with thermal mass. Equations and methods are given to calculate the minimum thermal load resulting from thermal mass from weather data files, TMY or TMY2 files. A design equation is given as a guideline to determine the amount of thermal mass required to reduce the thermal load with given weather conditions.

scholarly journals Impregnation of Wood with Microencapsulated Bio-Based Phase Change Materials for High Thermal Mass Engineered Wood Flooring

2018 ◽  
Vol 8 (12) ◽  
pp. 2696 ◽  
Author(s):  
Damien Mathis ◽  
Pierre Blanchet ◽  
Véronic Landry ◽  
Philippe Lagière
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Sugar Maple ◽  
Heat Storage ◽  
Red Oak ◽  
Thermal Mass ◽  
Microencapsulated Phase Change Material ◽  
Wood Flooring ◽  
Engineered Wood ◽  
Change Material

Wood is a porous material that can be impregnated and have enhanced properties. Two species of hardwood, red oak (Quercus rubra L.) and sugar maple (Acer saccharum Marsh.), were impregnated in a reactor with a microencapsulated phase change material. The objective was to enhance the thermal mass of wood boards used as surface layers for engineered wood flooring manufacturing. Preliminary experiments were conducted on small samples in order to define suitable impregnation parameters, based on the Bethell cycle. Thin wood boards were impregnated with a microencapsulated phase change material dispersed into distilled water. Several cycles of pressure were applied. Heating storage of the impregnated wood boards was determined using a dynamic heat flow meter apparatus method. A latent heat storage of 7.6 J/g over 3 °C was measured for impregnated red oak samples. This corresponds to a heat storage enhancement of 77.0%. Sugar maple was found to be harder to impregnate and thus his thermal enhancement was lower. Impregnated samples were observed by reflective optical microscopy. Microcapsules were found mainly in the large vessels of red oak, forming aggregates. Pull-off tests were conducted on varnished samples to assess the influence of an impregnation on varnish adhesion and no significant influence was revealed. Engineered wood flooring manufactured with impregnated boards such as characterized in this study could store solar energy and thus improve buildings energy efficiency. Although wood is a material with a low-conductivity, the thermal exchange between the PCM and the building air could be good enough as the microcapsules are positioned in the surface layer. Furthermore, flooring is an area with frequent sunrays exposure. Such high thermal mass EWF could lead to energy savings and to an enhancement of occupant’s thermal comfort. This study aimed to characterize the potential of impregnation with MPCM of two wood species in order to make high thermal mass EWF.

EXPERIMENTAL INVESTIGATION OF PERFORMANCE IMPROVEMENT OF HOUSEHOLD REFRIGERATOR USING PHASE CHANGE MATERIAL

2013 ◽  
Vol 21 (04) ◽  
pp. 1350029 ◽  
Author(s):  
MD. IMRAN HOSSEN KHAN ◽  
HASAN M. M. AFROZ
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Melting Point ◽  
Phase Change ◽  
Phase Change Material ◽  
Performance Improvement ◽  
Thermal Load ◽  
Storage System ◽  
Refrigeration Cycle ◽  
Change Material

An experimental investigation has been carried out to know about the performance improvement of a household refrigerator using phase change material (PCM). PCMs are used as latent heat thermal storage system to enhance the heat transfer of the evaporator. PCM is located behind the five sides of the evaporator cabinet in which the evaporator coil is immersed. Water (melting point 0°C) and Eutectic solutions (melting point −5°C) are used as PCMs for this experiment at different thermal loads. Depending on the types of PCM and thermal load, around 20–27% COP improvement of the refrigeration cycle has been observed with PCM with respect to without PCM. With the increase of the quantity of PCM (0.003 to 0.00425 m3) COP increases about 6%. Between two different PCMs the COP improvement for Eutectic solution is higher than Water. The experimental results with PCM confirm that, depending on the thermal load and the types of PCM average compressor running time per cycle is reduced significantly and it is found about 2–36% as compared to without PCM.

An Investigation on Chevron Plate Heat Exchanger Filled With Organic Phase Change Material

2020 ◽  
Author(s):  
Sunil Kumar ◽  
Ashok Thyagarajan ◽  
Debjyoti Banerjee
Keyword(s):  
Heat Exchanger ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Load ◽  
Load Capacity ◽  
Plate Heat Exchanger ◽  
Hot Water ◽  
Plate Heat ◽  
Change Material

Abstract Thermal management is one of the challenging areas in the view of shrinking devices size requiring efficient cooling to take care of the thermal load. The shrinking size of devices require efficient cooling for thermal load balance capabilities. This complicated requirement can be fulfilled with the help of Thermal Energy Storage (TES) systems. Phase Change Material (PCM) is one of the best examples of TES system. This paper deals with experimental investigation on Chevron Plate Heat Exchanger (CPHE) filled with an organic PCM PureTemp 29. PCM offers efficient performance in storing and releasing large quantities of thermal energy at any given temperature. Water is used as a Heat Transfer Fluid. The melting of PCM also known as discharging is studied at 5, 8 and 10 GPH. The flow of hot water at 38 °C and 32 °C through CPHE leads to melting of PCM known as discharging process. While, the flow of cold water at 20 °C and 26°C respectively through CPHE leads to solidification of PCM known as charging process. Load capacity and thermal efficiency of the PCM has been discussed in order to provide and estimation for future design modifications and efficiency enhancement of heat exchangers.

An analysis of phase change material as thermal mass

2008 ◽  
Vol 464 (2092) ◽  
pp. 1029-1056 ◽  
Author(s):  
M.J Richardson ◽  
A.W Woods
Keyword(s):  
Phase Change ◽  
Penetration Depth ◽  
Phase Change Material ◽  
Dimensionless Parameter ◽  
Thermal Inertia ◽  
Thermal Mass ◽  
Temperature Dependent ◽  
Conventional Concrete ◽  
Infinite Mass ◽  
Change Material

Temperature fluctuations within a building can be attenuated by thermal mass. Adding phase change material (PCM) to thermal mass increases the effective heat capacity during the phase transition. This can anchor the temperature of the mass in a narrow band around the melting point of the PCM, further reducing the temperature swings perceived by occupants of the room. A simple dimensionless model for thermal mass forced by a sinusoidally varying air temperature is developed to calculate the performance of the PCM. The mass temperature satisfies the heat equation, with a temperature-dependent thermal diffusivity, and is solved numerically. For a given PCM, the energy stored and returned to the room, the surface temperature amplitude and the penetration depth of heat pulses into a hypothetical semi-infinite mass can all be calculated as a function of a single dimensionless parameter. For optimal performance, the latent heat of the PCM should be as large as possible, the melting temperature range should be narrow and the thickness of the mass should exceed the penetration depth. The PCM wallboard is shown to be potentially as effective as conventional concrete, so lightweight buildings could enjoy the benefits of thermal inertia commonly associated with heavyweight structures.

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