scholarly journals Application of Phase Change Materials and Conventional Thermal Mass for Control of Roof-Generated Cooling Loads

2020 ◽  
Vol 10 (19) ◽  
pp. 6875
Author(s):  
Jan Kośny ◽  
William Anthony Miller ◽  
David Yarbrough ◽  
Elisabeth Kossecka ◽  
Kaushik Biswas
Keyword(s):  
Energy Demand ◽  
Phase Change Materials ◽  
Peak Load ◽  
Thermal Response ◽  
Climatic Conditions ◽  
Thermal Mass ◽  
Design Strategies ◽  
Response Characteristics ◽  
Intense Solar Radiation ◽  
Cooling Loads

Among all of the internal fabric and external enclosure components of buildings, sloped roofs and adjacent attics are often the most dynamic areas. Roofs are exposed to high temperature fluctuations and intense solar radiation that are subject to seasonal changes in climatic conditions. Following the currently rising interests in demand-side management, building energy dynamics, and the thermal response characteristics of building components, this paper contains unpublished results from past studies that focused on innovative roof and attic configurations. The authors share unique design strategies that yield significant reduction of daytime roof peak temperatures, thermal-load shavings, and up to a ten-hour shift of the peak load period. Furthermore, advance configurations of the roofs and attics that are discussed in this paper enable over 90% reductions in roof-generated peak-hour cooling loads and sometimes close to 50% reductions in overall roof-generated cooling loads as compared with traditionally constructed roofs with the same or similar levels of thermal insulation. It is expected that the proposed new roof design schemes could support the effective management of dynamic energy demand in future buildings.

scholarly journals Incorporation of Phase Change Materials in Lightweight Aggregate Concrete

2020 ◽  
Vol 16 ◽  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Response ◽  
Lightweight Aggregate ◽  
Hydration Heat ◽  
Lightweight Aggregate Concrete ◽  
Thermal Mass ◽  
Hardened Concrete ◽  
Bioclimatic Design ◽  
Pumice Aggregates

An investigation on some methods for the incorporation of phase change materials (PCMs) into concrete and their effect on its properties is presented. PCMs are characterized by high latent fusion heat, which can increase thermal mass of concrete and contribute to the bioclimatic design of buildings. Concrete compositions with different aggregates (limestone, lightweight or their combination), as well as with different PCMs (paraffinic and dodecyl alcohol) were prepared by different incorporation methods (impregnation to lightweight aggregates or immersion of concrete specimens). Properties of fresh and hardened concrete were studied, as well as hydration heat, thermal response and flammability. The results revealed that the selected PCMs do not significantly affect the properties of concrete. Regarding hydration heat, the presence of the PCM in concrete contributes to a decrease of the temperature peak during hydration which also occurs delayed. Thermal response measurements showed that concrete with purely pumice aggregates has a much better thermal behavior than the other two compositions, while the existence of PCM causes large or small increase of concretes heat capacity, in temperature near to each PCM’s melting point. Finally, appropriate application of PCMs is needed in order to moderate the reported effect on concrete’s fire resistance

Energy demand reduction in the built environment using shallow geothermal integrated energy systems – A comprehensive review: Part I. Design consideration of ground heat exchanger

2021 ◽  
pp. 1-62
Author(s):  
Balaji Kumar
Keyword(s):  
Heat Exchanger ◽  
Built Environment ◽  
Energy Demand ◽  
Numerical Models ◽  
Thermal Response ◽  
Open Loop ◽  
Climatic Conditions ◽  
Heat Transfer Fluid ◽  
Ground Heat Exchanger ◽  
Comprehensive Review

Abstract The research collection aims at finding the various possible opportunities for the effective integration of shallow geothermal energy (SGE) to decrease the energy demand in the built environment and to reduce emission associated with it. The integration of SGE with heat pump using pipe network is extensively reviewed. The open loop and closed loop (vertical, horizontal, energy piles) pipe networks are the most common type of ground heat exchanging methods. The objective of the review is to improve the heat exchanger effectiveness through various design aspects according to the local climatic conditions. This comprehensive review part II contains the research details pertaining to the last two decades about ground heat exchangers (geometrical aspects, borehole material, grout material, thermal response test, analytical and numerical models). Also, the factors influencing the ground heat exchanger's performance such as heat transfer fluid, groundwater flow, and soil properties are discussed in detail. This paper highlights the recent research findings and a potential gap in the ground heat exchanger.

scholarly journals Numerical Simulation of a Novel Dual Layered Phase Change Material Brick Wall for Human Comfort in Hot and Cold Climatic Conditions

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4032
Author(s):  
Atiq Ur Rehman ◽  
Shakil R. Sheikh ◽  
Zareena Kausar ◽  
Sarah J. McCormack
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Characteristics ◽  
Extended Period ◽  
Climatic Conditions ◽  
Heat Of Fusion ◽  
Thermal Mass ◽  
Brick Wall ◽  
Latent Heat Storage ◽  
Human Comfort

Phase change materials (PCMs) have a large number of applications for thermal energy storage (TES) and temperature reduction in buildings due to their thermal characteristics and latent heat storage capabilities. The thermal mass of typical brick walls can be substantially increased using a suitable PCM primarily based on phase change temperature and heat of fusion for different weather conditions in summer and winter. This study proposed a novel dual-layer PCM configuration for brick walls to maintain human comfort for hot and cold climatic conditions in Islamabad, Pakistan. Numerical simulations were performed using Ansys Fluent for dual PCMs layered within a brick wall for June and January with melting temperatures of 29 °C and 13 °C. This study examined and discussed the charging and discharging cycles of PCMs over an extended period (one month) to establish whether the efficacy of PCMs is hindered due to difficulties in discharging. The results show that the combined use of both PCMs stated above provides better human comfort with reduced energy requirements in Islamabad throughout the year than using a single PCM (29 °C) for summer or winter (13 °C) alone.

scholarly journals The way to limit emission – energy efficient buildings. The example of the largest facility in Poland in nearly

2020 ◽  
Vol 29 (1) ◽  
pp. 81-92
Author(s):  
Ewa Figiel ◽  
Dorota Leciej-Pirczewska
Keyword(s):  
Co2 Emission ◽  
Energy Demand ◽  
Energy Use ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Design Strategies ◽  
Energy Technologies ◽  
Mixed Use ◽  
Before And After ◽  
Reduction Of Co2

In Szczecin a mixed-use complex Posejdon is being constructed. It will be the first nearly zero-energy building (NZEB) in Poland that meets the strict ecological standards that all buildings will have to meet after January 2021. The project was presented at the COP24 United Nations Climate Change Conference in Katowice. The calculated building CO2 emission is very low. Based on the example of the Posejdon complex’s office-service section before and after renovation modern technical solutions for meeting the buildings energy demand and the resulting reduction of CO2 emission have been presented. The emissions were obtained after the calculation of energy use in accordance with Polish and European regulations concerning the energy performance of buildings using climatic conditions taken from a Polish meteorological database. The described renewable energy technologies implemented in the Posejdon building, serve as a reference to export management and design strategies to other NZEB with similar characteristics in the same region.

scholarly journals A short review on passive strategies applied to minimise the building cooling loads in hot locations

2021 ◽  
Vol 15 (2) ◽  
pp. 20-30
Author(s):  
Qudama Al-Yasiri ◽  
Márta Szabó
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Phase Change Materials ◽  
Weather Conditions ◽  
Short Review ◽  
Building Energy ◽  
Passive Strategies ◽  
Shading Devices ◽  
Building Cooling ◽  
Cooling Loads

Cooling and air-conditioning systems are responsible for the highest energy consumption in buildings located in hot areas. This high share does not only increase the building energy demand cost but also increases the environmental impact, the topmost awareness of the modern era. The development of traditional systems and reliance on renewable technologies have increased drastically in the last century but still lacks economic concerns. Passive cooling strategies have been introduced as a successful option to mitigate the energy demand and improve energy conservation in buildings. This paper shed light on some passive strategies that could be applied to minimise building cooling loads to encourage the movement towards healthier and more energy-efficient buildings. For this purpose, seven popular passive technologies have been discussed shortly: multi-panned windows, shading devices, insulations, green roofing, phase change materials, reflective coatings, and natural ventilation using the windcatcher technique. The analysis of each strategy has shown that the building energy could be improved remarkably. Furthermore, adopting more passive strategies can significantly enhance the building thermal comfort even under severe weather conditions.

Low Exergy Heating and Cooling in Residential Buildings

2011 ◽  
Author(s):  
Michael Jochum ◽  
Gokulakrishnan Murugesan ◽  
Kelly Kissock ◽  
Kevin Hallinan
Keyword(s):  
Cooling System ◽  
Residential Buildings ◽  
Thermal Mass ◽  
Design Strategies ◽  
High Quality ◽  
Small Temperature ◽  
Transfer Rates ◽  
Heating And Cooling ◽  
Solar Wall ◽  
Cooling Loads

Exergy is destroyed when work is degraded by friction and turbulence and when heat is transferred through finite temperature differences. Typical HVAC systems use a combination of high quality energy from combustion and electricity to overcome relatively small temperature differences between the building and the environment. It is possible to achieve the heating/cooling necessary to maintain comfort in a building without these high quality energy sources and their high potential-energy destruction. A low-exergy heating and cooling system seeks to better match the quality of energy to the loads of the building and thus to minimize exergy destruction and increase the exergetic efficiency of the building’s heating and cooling system. The method described here for low exergy building system design begins by minimizing overall heating and cooling loads using a tight, highly-insulated envelope and passive solar design strategies. Next a low-exergy heating and cooling system is designed that uses hydronic radiant heating and cooling in floors, along with high thermal mass. The large surface area of the floors enable low fluid flow rates and relatively small temperature differences to achieve heat transfer rates that would traditionally be driven by high temperature differentials and flows. The building uses a solar wall to passively drive ventilation requirements and earth tubes to condition the ventilation air. High thermal mass in the floor reduces peak loads and eliminates the need for solar thermal storage tanks. Thus, this paper begins to explore the practical limits of low-exergy design.

scholarly journals A Review on Shape-Stabilized Phase Change Materials for Latent Energy Storage in Buildings

2020 ◽  
Vol 12 (22) ◽  
pp. 9481
Author(s):  
Monika Gandhi ◽  
Ashok Kumar ◽  
Rajasekar Elangovan ◽  
Chandan Swaroop Meena ◽  
Kishor S. Kulkarni ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Liquid State ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Temperature Fluctuations ◽  
Good Evidence ◽  
Thermal Mass ◽  
Indoor Temperature

Many countries in the Global South have hot and dry climates with large diurnal temperature variations, which leads to large demand for space cooling—which is likely to increase with climate change. A common approach to dampen the indoor temperature fluctuations and thus reduce cooling energy demand is the use of thermal mass. However, the use of lightweight structures in many cities (e.g., high-rise structures, or for earthquake protection) precludes the use of traditional forms of thermal mass. Therefore, phase change materials (PCMs) are being widely developed as thermal energy storage systems for building applications. However, challenges such as leakage of PCMs in liquid state and their low thermal conductivity, still limit their applications in buildings. In this paper, we review the potential of Form or Shape-Stabilized Phase Change Materials (SSPCMs), which are developed by incorporating the PCM into a supporting matrix to prevent leakage in liquid state whilst improving thermal conductivity. We review different methods of preparation and the resultant thermal properties and chemical stability. We find good evidence in the literature for SSPCMs to reduce PCM leakage in liquid state, dampen indoor temperature fluctuations, and potentially alleviate peak energy demand by shifting peak loads to off-peak periods.

scholarly journals Using PCM in Two Proposed Residential Buildings in Christchurch, New Zealand

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6025 ◽  
Author(s):  
Erik Schmerse ◽  
Charles A. Ikutegbe ◽  
Amar Auckaili ◽  
Mohammed M. Farid
Keyword(s):  
New Zealand ◽  
Phase Change Materials ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
Homeless People ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Simulation Software ◽  
Thermal Mass

A characteristic feature of lightweight constructions is their low thermal mass which causes high internal temperature fluctuations that require high heating and cooling demand throughout the year. Phase change materials (PCMs) are effective in providing thermal inertia to low-thermal-mass buildings. This paper aims to analyse the thermal behaviour of two proposed lightweight buildings designed for homeless people and to investigate the potential benefit achievable through the use of different types of PCM in the temperate climatic conditions of Christchurch, New Zealand. For this purpose, over 300 numerical simulations were conducted using DesignBuilder® simulation software. The bulk of the simulations were carried out under the assumption that the whole opaque building envelope is equipped with PCM. The results showed significant energy saving and comfort enhancement through the application of PCMs. The integration of PCM in single-structure components led to substantial energy savings between 19% and 27% annually. However, occupant behaviour in terms of ventilation habits, occupancy of zones, etc. remains one of the biggest challenges in any simulation work due to insufficient data.

AN INNOVATIVE COOLING ROOF REDUCING THE ENERGY DEMAND FOR A NON-RESIDENTIAL BUILDING IN TROPICAL CLIMATE

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mauro Rodolfo Cepeda Ortiz
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Residential Building ◽  
Design Strategies ◽  
Building Roof ◽  
Correct Orientation ◽  
Energy Demands ◽  
Tropical Climates ◽  
Roof Design ◽  
Cooling Loads

In tropical climates, high temperatures and high levels of humidity, coupled with inadequate design of buildings, lead to an increase in thermal loads. The roof is the element of the building that receives the greatest amount of solar radiation throughout the year. As a result, the roof receives excessive thermal gain, which is then transmitted to the rest of the building and leads to an increase in final energy demands. Much of this can be solved with passive design strategies. With respect to the main problem of the building roof, natural ventilation can provide improvements in reducing temperatures in this area and the structure below. First, through correct orientation, a reduction of the building’s annual energy consumption by 24.32% was achieved. Secondly, by applying different configurations of the roof a reduction of 78.09% in roof cooling loads was obtained. This was brought about through a combination of optimization of the roof design for natural ventilation and the application of reflective materials with a U value of 0.13 W / mK. From the second scenario it was reduced by 14.74% with the applied strategy.

scholarly journals Using PCM in two proposed residential buildings in Christchurch, New Zealand

2020 ◽  
Author(s):  
Erik Schmerse ◽  
Charles Ikutegbe ◽  
Amar Auckaili ◽  
Mohammed Farid
Keyword(s):  
New Zealand ◽  
Energy Saving ◽  
Phase Change Materials ◽  
Residential Buildings ◽  
Thermal Inertia ◽  
Homeless People ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Simulation Software ◽  
Thermal Mass

A characteristic feature of lightweight constructions is their low thermal mass which causes high internal temperature fluctuations that require high heating and cooling demand throughout the year. Phase Change Materials (PCMs) is effective in providing thermal inertia to low thermal mass buildings. The aim of this paper is to analyse the thermal behaviour of two proposed lightweight buildings designed for homeless people and to investigate the potential benefit achievable through the use of different types of PCM in the temperate climatic conditions of Christchurch, New Zealand. For this purpose, over 300 numerical simulations have been conducted using the simulation software DesignBuilder®. The bulk of the simulations were carried out under the assumption that the whole opaque building envelope is equipped with PCM. The results showed significant energy saving and comfort enhancement through the application of PCMs. Thereby, annual energy saving of over 50 % was reached for some of the PCMs considered. Additionally, the effectiveness of single, PCM-equipped structure components was investigated and substantial benefits between 19 and 27 % annual energy saving were achieved. However, occupant behaviour in terms of ventilation habits, occupancy of zones etc. remains one of the biggest challenges in any simulation work due to insufficient data.

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