Phase change materials influence on temperature variatio buildings

Effect of melting point on thermodynamics of thin PCM reinforced residential frame walls in different climate zones

Outline of the incorporation of phase change materials in radiant systems

Buildings use more than 40% of the total power consumed in India. Therefore, implementing energy conservation within buildings is of prime concern. Utilization of passive design parameters, such as Phase Change Material (PCM) incorporation, for energy conservation in buildings is thus a lucrative option. Incorporating PCMs within elements result in lowering of heat gain and temperature within the building. A number of simulation and experimental studies on PCM incorporated buildings, have been carried out. The advancements made in last forty years in the field of PCMs and their utilization as Thermal Energy Storage (TES) medium for buildings have been reviewed and presented in this study. This study focusses on PCM incorporation which is sensitive to its properties and climatic parameters of the location. Thus, there is a need of benchmarking the PCM for their application in buildings. Focus is on buildings in tropical hot climatic conditions, where reduction in cooling load is a challenge. This study lays emphasis on selection of appropriate PCMs based on its phase change temperature. Thermal conductivity, specific heat and latent heat are other properties which must be evaluated before PCM selection and implementation within buildings. The study also encompasses different methods of PCM incorporation being implemented across the world and have marked advantages and disadvantages of each followed by their impact in terms of energy savings.

Incorporating Phase Change Materials (PCMs) into indoor environments can enhance users' thermal comfort and improve the building's energy efficiency. However, the number of PCM studies in hot and humid climates, such as most Brazilian conditions, is comparatively less developed than research for temperate climates. This article investigates the influence of climatic parameters on the PCMs' function to enhance user thermal comfort in an office model in Brazilian climates employing thermo-energy simulation using EnergyPlus for 95 cities with adaptive thermal comfort as a performance indicator. We employed machine learning techniques, including Gradient Boosting and Feature Importance, to quantify the influence of climate parameters, followed by Principal Component Analysis clustering. Results show that incorporating PCMs can potentially increase user thermal comfort in part of Brazil, mainly in cities with average temperatures below 21°C. The comfort increase is not homogeneous, being more relevant in regions with colder temperatures and higher altitudes. When considering better-performing cities, the most influential climatic parameters were dry bulb temperature, relative humidity, and wind direction.

Improving the energy efficiency of passive PCM system using controlled natural ventilation

A novel method to evaluate phase change materials' impact on buildings' energy, economic, and environmental performance via controlled natural ventilation

Study on foam concrete incorporated with expanded vermiculite/capric acid PCM – A novel thermal storage high-performance building material

Evaluating the passive and free cooling application methods of phase change materials in residential buildings: A comparative study

Innovation and progress in the incorporation of phase change materials into radiant floor systems

The energy demand for maintaining the required thermal comfort in the building is always an increasing trend. The use of an air conditioner in the building for providing thermal comfort consumes more energy, and it leads to negative environmental impacts. Thermal energy storage (TES) systems are essential to reduce energy consumption in the building. The phase change material (PCM)-based TES in the building has attracted attention in the recent years. In the PCM-based TES system, the heat energy gained during daytime is absorbed by the PCM and the stored energy is released during the night time. The objective of the work is to control the room temperature fluctuations by incorporating PCM in the building roof. The experiments are conducted in two identical model buildings: one is constructed with the implementation of PCM, and another one is constructed without the implementation of PCM in the building roof. It has been observed that the temperature fluctuations in the building are reduced by the use of PCM in the roof. The average peak temperature rise is reduced about 1–2 °C in the building with PCM incorporation in the roof, and thus, the energy required for maintaining the thermal comfort of the room is greatly reduced.

The use of organic phase change materials (PCM – O) for thermal conditioning of agricultural products is proposed here. In particular, the capacity of PCM – O for controlling temperature is studied for sudden variation of external temperature conditions. Two different situations (a thermal jump and a periodic oscillation) using a simple and appropriate simulation model are presented. This model allows the evaluation of the temperature distribution and the interface position as a time function in the PCM. The obtained results show that the use of these substances is appropriate to control the required temperature of the agricultural products. Besides, these substances can reduce the cost during the transport of these products. PRACTICAL APPLICATIONS Several agricultural products, such as fruits and vegetables, need adequate conditions of storage and transport. It is necessary to maintain certain conditions of temperature and controlled atmosphere. Each product needs different temperature conditions. Temperatures must be maintained within a range that would guarantee the preservation of a product's organoleptic characteristics during a certain period. Thus, the use of phase change materials (PCM) for these purposes has been proposed, to reduce the energy consumption and, accordingly, the cost of transportation. Agricultural products can suffer thermal stress when they are exposed to extreme conditions, such as a sudden change or an oscillation in the external temperature. PCM can control and attenuate the influence of the external temperature on the agricultural product.

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 time of the peak load on the electrical grid. Phase change materials (PCMs) are promising material for that purpose. When impregnated or encapsulated into wallboard or concrete systems, PCMs can greatly enhance their thermal energy storage capacity and effective thermal mass. In this work, a numerical study is conducted to investigate the characteristics of PCMs in building applications. For that purpose a one-dimensional, transient heat equation for a multilayered building envelope is solved using the Crank-Nicolson scheme. The effect of PCM is modeled with a latent heat source term. The code also incorporates sun loading and uses real weather data. Using this code a PCM composite wallboard incorporated into the walls and roof of a residential building was examined. The PCM performance was studied under all seasonal conditions using TMY3 data for exterior boundary conditions. Comparisons were made between different PCM wallboard locations. This work shows that there is an optimized location for PCM placement within building envelope and the location depends on the thermal resistance of the layers between the PCM and the exterior boundary. The energy savings potential was identified by comparing the performance of the PCM wallboard with the performance of a building envelope without PCM. This work shows that a PCM composite wallboard enhanced building can reduce the annual cooling load from the walls by as much as 19.7% and from the roof by as much as 8.1%. Similarly, the annual heating loads can be reduced by as much as 6% and 6.4% for the walls and roof respectively. It was also shown that the peak electricity load can be shifted by as much as three hours in the summer for a south facing wall. Studies are also conducted to compare the PCM performance across three climate zones. This work shows that PCM performance varies significantly across these zones.

Advancements in phase change materials for energy-efficient building construction: A comprehensive review

Improving performance of household refrigerators by incorporating phase change materials

Numerical simulation of thermal mass enhanced envelopes for office buildings in subtropical climate zones