Increase Building Energy Efficiency Research Articles

External Thermal Insulation Composite Systems (ETICS) from Industry and Academia Perspective

External Thermal Insulation Composite System (ETICS) is a commonly used solution in EU countries to increase building energy efficiency. The article describes ETICS in terms of environmental impact from two perspectives, i.e., industry and academia. In EU countries, ETICS manufacturers to place construction products to the market must subject it to the assessment and verification of constancy of performance (AVCP). The basis of this process is the European Technical Assessment (ETA). Based on the number of issued and valid ETAs for ETICS and the number of Environmental Product Declarations (EPDs), the dimension of sustainability issues was discussed. Analysis of one of the environmental indicators (Global Warming Potential—GWP) for ETICS with EPS, XPS, and MW showed only a general trend. However, there are significant differences between the values of the GWP and other environmental indicators that one can use for future AVCP of construction products. In the light of the research described in the paper, it seems reasonable to conclude that AVCP for ETICS in terms of sustainability will be challenging to implement in practice-based only on environmental indicators according to EN 15804. The article also reviews scientific publications on the sustainability of ETICS.

Eminent Domain Law as Climate Policy

In 2019, several state legislatures adopted aggressive clean energy laws and other states are poised to do the same. These policies require electric utilities to secure all of the electricity they sell to customers from carbon-free energy resources by a specified date and many also require the state to drastically reduce carbon emissions from the transportation sector, increase energy efficiency in buildings, and otherwise decarbonize their economies. In order to meet these mandates, states must transform the physical infrastructure used to create and transport energy. This will require building new power plants that run on carbon-free energy resources like wind, solar, hydropower, or nuclear energy; constructing the electric transmission lines and other infrastructure needed to deliver these energy resources to consumers; setting standards and mandates for new buildings, vehicles, and transportation infrastructure that will reduce carbon emissions; and providing direct funding, tax incentives, new permitting processes, and staff to support the public and private actors that will implement these changes. These needs are becoming well documented. What remains completely unexplored, however, is the potential for state property law reform — most notably eminent domain law — to limit the development of fossil fuels and promote the growth of alternative energy to support these new clean energy policies. This Article contends that states should consider eliminating existing eminent domain rights for fossil fuel projects and extending eminent domain rights for clean energy projects as part of their state climate policies. Moreover, each state’s approach to eminent domain reform may differ based on the current energy mix in the state as well as the potential for technological development. These policy conversations regarding the use of eminent domain for energy projects are critical to developing robust state clean energy laws. They also can provide a useful template for Congress if, in the future, it decides to enact federal climate policy.

An Investigation on Natural Window Ventilation: Improving Indoor Air Quality and Energy Efficiency in an Office Building

With the increment in time spent indoors, the contingence between building occupants and indoor air pollution has been lengthened. Accordingly, indoor air quality became a significant factor since the poor conditions can influence the occupants’ health and efficiency. Indoor air quality is mainly concerned with physical and thermophysical factors in conditioned environments and is related to occupants’ satisfaction levels on a variety of variables such as fresh air adequacy, air temperature, odor, humidity, and air velocity. This paper aims to investigate natural ventilation occupant-control methods to improve indoor air quality and increase building energy efficiency considering clean air intake levels and indoor air temperature levels. For this, variables related to climatic conditions, ventilation systems, and occupant’s control on window opening were investigated to provide healthy and liveable conditions. To comply with these goals, in an open-plan office building, the levels of indoor air quality were determined with the help of DesignBuilder simulation by comparing obtained values under different case modeling variations.

Sizing and performance analyses of a combined heating and cooling system with the integration of short- and long-term storages

Technological advancements in the utilization of renewable energy sources have unveiled potentials for increasing building energy efficiency. Integrating heat pump-based energy systems with thermal storages is a suitable option to meet the thermal requirements of modern buildings and exploiting the available renewable energy sources. However, how to size the main components of a heat pump-based energy system with the integration of short- and long-term storages is not yet well explored. Therefore, this study focused on the design and performance analyses of an integrated heating and cooling system consist of a heat pump, borehole long-term thermal storage, and hot water tank short-term thermal. Heat pump models were introduced as parametric models based on the producer data. The dynamic thermal model of the energy system was developed and analysed in MATLAB. Different combinations of heating and cooling loads were tested. Integration of cooling and heating systems was discussed through different operation strategies and challenges were addressed. The results of the parametric analysis identified the key parameters affecting the design of components and efficiency of the system. Moreover, the results showed that lower cooling to heating load ratio leads to an excessive reduction of the ground temperature and overall efficiency over the long-term operation.

Energetic analysis of a thermal building using geothermal and solar energy sources

The building sector is growing at a rapid pace and has become the third largest consumer of fossil energy, after industry and transportation. To achieve a significant reduction in building energy consumption, aiming a sustainable development, passive methods are not enough: renewable energy technologies should be integrated with passive building concepts and systems, in order to improve energy efficiency. Renewable energy sources (RES) have been largely deployed as green energy producers, reducing power consumption while minimizing greenhouse emissions — they are derived from natural processes that are continuously replenished.This study provides a case study of the implementation of this type of energy resources, in this case geothermal and solar energy sources, in an existing thermal building located in the interior of Portugal, using renewable technologies to satisfy electrical and thermal energy loads.Through dynamic thermal simulation, using the TRACE 700 software, it was possible to obtain results very close to measured ones, and also to assess the implementation of appropriate rationalization measures to reduce energy consumption and increase building energy efficiency.

Using Latent Energy of Water-ice Phase Change to Reduce Energy Losses in Buildings in Cold Climate

Energy efficiency in buildings is a very important challenge that has to be faced in order to achieve the aims set by the new EU directive on Building energy efficiency encouraging nearly zero energy buildings. Unfortunately in countries with cold climate it is very hard to achieve this goal. The thickness of insulation needed to reach low energy consumption in cold climate is very big and in many cases it is not economically feasible. There is a need for new solutions for increasing building energy efficiency. In this paper a new solution for increasing building energy efficiency is proposed. It is proposed to use the latent energy of water-ice phase change to reduce heat conduction losses through building envelope. The latent energy is recovered by using low potential heat source. In this paper the validity of the proposed new solution is tested on a one dimensional scale – homogeneous infinite wall. The presented methodology is chosen to calculate systems operational efficiency throughout the whole year.

Use of vegetation to increase building energy efficiency: application to a real case study

The research here presented deals with the relationship between vegetation and architecture, and how its presence can influence a building project and performance. In the last years, many ways of integrating green in building envelopes have already been experimented, for their potential of reducing thermal loads; the research investigates a specific solution, the vertical forest, which integrates trees and small bushes in specific permanent planters on balconies of high-rise buildings. The main scope is to understand if trees, treated as shadings, can really affect positively the building energy consumptions. Moreover, other aspects, such as trees mechanical stability, construction issues and maintenance are deepened. Through a particular case study, energy consumptions are analysed using dynamic simulations tools, developed with Grasshopper™ and EnergyPlus™ software, in which trees are considered as special external shadings, characterized by a variable permeability to solar radiation during the year. Results demonstrate that trees can contribute to reduce energy loads, depending on species and orientation, especially in association with traditional shading systems. Eventually, some guidelines on technological and construction aspects, as well as on trees species selection, are given, in order to assure the optimal vegetation life and to maximize its benefits on the building.

Feasibility study on improving the performance of atomization liquid desiccant dehumidifier with standing-wave ultrasound

Abstract Liquid desiccant dehumidification systems are promising to increase building energy efficiency. Furthermore, the dehumidification performance can be improved using ultrasound capable of atomizing liquid desiccant into numerous droplets. However, the droplets fall rapidly by gravity and converge into liquid films at the dehumidifier’s bottom, reducing the effective transfer time, which is another crucial factor for dehumidification, and the energy efficiency of the ultrasonic system. This study investigated a new and improved method using a standing-wave ultrasound and its levitation effects; using this method, desiccant droplets can be levitated and vibrated in humid air, and thereby, the mass transfer can be increased. The feasibility of the method was carefully verified through comparative experiments within an improved ultrasonic liquid desiccant system (ULDS), which was switched between the conventional traveling-wave and the standing-wave ultrasound. Performance criteria related to the moisture removal rate and specific energy consumption of the ultrasonic system were adopted. We found that the standing-wave ultrasound significantly improved the dehumidification performance of ULDS (by 56% on average) at a negligible additional energy cost. Moreover, low-concentration desiccant solutions become useable, and the ultrasonic device is more energy-efficient in the standing-wave ULDS. This study can aid in improving the dehumidification performance of ULDSs.

A Review of Roofing Methods: Construction Features, Heat Reduction, Payback Period and Climatic Responsiveness

The roofs of buildings play an essential role in energy efficiency because a significant amount of solar radiation is absorbed by roofs in hot weather and a significant amount of heat is lost through roofs in cold weather. This paper is a systematic literature review about roofing methods for flat roofs. Ten roofing methods are reviewed in this paper. They are concrete roof, cool roof, insulated roof, roof garden, photovoltaic panels’ roof, biosolar roof, double-skin roof, roof ponds, skylight roof, and wind catcher. The review covers each roof’s main features, heat flux reductions, payback periods, and the appropriate climate for its implementation. Furthermore, the basic principles for selecting appropriate roofing methods are discussed and future studies for integrating these roofing methods are suggested. Some of these methods can eliminate the need of installing HVAC (Heating Ventilation and Air-conditioning) systems and others can achieve a high percentage of heat reduction if they are the right choice and they are implemented in the right circumstances. An incorrect selection could result in mild to severe energy penalties. The review contributes to the increasing knowledge about sustainable roofing and helps designers to increase building energy efficiency by selecting the appropriate roofing method.

Indexes for passive building design in urban context – indoor and outdoor cooling potentials

In this paper, we propose a practical approach for decision-making regarding passive cooling design for buildings in dense urban contexts. For non-cooled buildings under temperate climates, assessment of summer thermal discomfort determines the usual passive cooling design together with fossil energy and GHG savings at earth scale. However, passive cooling techniques for indoor climate can be also valuable for local environment impacts, especially urban heat islands’ mitigation. Lack of simple representative criteria and complexity of simulation outputs constitute a barrier for the development of passive cooling. Based on a study of a generic commercial building, we analyzed several designs with Sankey diagram and we developed two performance indexes. This chart synthesis of complex output data allows a direct comparison of design solutions. This analysis gives hints for better designer understanding of urban climate and building interactions for the studied passive cooling solutions: cool roofing, nocturnal natural ventilation and rooftop PV system as shading device. Our results show that nocturnal natural ventilation is efficient to moderate indoor overheating compared to the "cool roof". In addition, cool roofs reduce anthropogenic heat transferred to urban environment. PV panels as shading device mitigate summer discomfort and produce energy that increase building energy efficiency through the year. We defined two Key Performance Indexes (KPIs) to define cooling potential of both indoor and urban environment. These KPIs obtained for different temperate climates highlight new prospects for the design of efficient urban designs with controlled environmental impacts and decision process of stakeholders.

Survey of resident behaviour related to air conditioner operation in low-cost apartments of kuala lumpur

Predictions of air conditioner (AC) use can greatly facilitate efforts to increase energy efficiency in buildings and promote sustainability. In order to determine the statistical characteristics of occupant behaviour related to AC operation, a series of surveys were conducted between September 2013 and December 2015 in 63 dwellings within two apartments in Kuala Lumpur, Malaysia. Measurements were taken either in the bedroom or living room of each dwelling. The results indicate that occupants who use ACs more frequently tend to use them for longer periods. It was found that AC use in bedrooms is not affected by outdoor temperature but is controlled by the habitual behaviour of the occupant. AC usage in living rooms slightly increases with increases in outdoor temperature. AC usage predominantly occurs at night time, with a maximum of 50 % of occupants using ACs in bedrooms. The start time and duration of use vary for each dwelling. These findings on stochastic resident behaviour might be useful for various building energy simulations in predicting realistic AC loads, particularly in tropical climates.

What next for energy-related building regulations?: the occupancy phase

ABSTRACTBuilding regulations are important policy instruments for increasing building energy efficiency. However, when it comes to actual energy use, studies have shown that improvements in building energy efficiency are offset by changes in the inhabitants’ comfort practices. Nevertheless, the improvement of energy efficiency continues to be a cornerstone in building regulations, with no consideration of how this simultaneously influences everyday practices. The example of Danish building regulations, which are among the strictest in Europe, is critically reviewed for the implications regulatory design can have for reducing energy consumption. Based on readings of policy documents, consultancy reports and research papers from the last two decades, this paper outlines where things go amiss during a building’s lifetime if a user perspective is excluded. The focus is on three phases: the development of new building technologies, the design and construction of buildings, and occupancy. The question of how building regulations could be redesigned to regulate energy use better is explored, along with what research and strategies are needed within four domains: developing alternative measures to energy per square meter; developing more advanced models simulating occupancy; improving feedback technologies’ usability; and the increased use of commissioning and post-occupancy evaluations.

IMPORTANCE OF HEAT INSULATION FOR CREATING ENERGY EFFICIENCY IN CURRENT BUILDINGS: BURSA, NILÜFER/TURKEY EXAMPLE

The majority of the current building stock in Turkey is composed of buildings that are not insulated. One of the most important items of the agenda is insulating these buildings in time to use energy efficiently (to create energy efficiency). Due to the increase of residential energy consumption related to heating and cooling, suggestions to speed up the transformation of uninsulated buildings to insulating buildings are needed. Similar to the rest of the world “Measures to Increase Energy Efficiency of Buildings” are among the future goals of administrational policies. Taking into consideration all the research in this area the residential Ataevler Quarter in the Nilufer district of the city of Bursa - the 4th largest city in Turkey - was selected for the analysis in the scope of this paper. There are a total of 2891 apartments in the research area, which is composed of 16 building complexes and 254 building blocks. The research will first analyze the current situation of the residential area. After the initial analyses CO 2 emissions (tons), heating energy need (kWh/m 2 ) and heat loss amount (kWh) that will have acquired after insulating uninsulated buildings will be presented. The analyses have shown that insulating walls and roofs of the current buildings will reduce CO 2 emissions and fuel consumption almost by 30%. The contribution of this savings to the national economy, budget of the users, and protection of the buildings and the environment is significant. It is believed that the data should be presented to and evaluated by relevant parties in order to contribute to the development of future strategies that aim to reduce energy consumption of current buildings to the minimum. Keywords : Energy efficiency, heat insulation, insulation of buildings

Experimental Study on Thermal Performance Improvement of Building Envelopes Integrated with Phase Change Materials in an Air-conditioned Room

Phase change materials (PCMs) are used to decrease the indoor temperature swing, keep the indoor environment comfortable and increase energy efficiency of buildings by enhancing the thermal storage capacity of building walls. This paper studied the thermal performance of the PCM wall and the reference wall when the air-condition ran continuously and intermittently through experiment. An experimental building with these two kinds of wall units was chosen, and the inner surface temperature and heat flow were measured. Results showed that the PCMs reduced the inner surface temperature 1°C and the inner surface heat flow about 40% during continuous air conditioning. Otherwise, when the air-condition ran intermittently by the working schedule, the cold releasing time of PCM wall was 2 hours longer than the reference wall. The PCMs can improved the thermal performance of building envelope significantly.

Time series analytics using sliding window metaheuristic optimization-based machine learning system for identifying building energy consumption patterns

Smart grids are a promising solution to the rapidly growing power demand because they can considerably increase building energy efficiency. This study developed a novel time-series sliding window metaheuristic optimization-based machine learning system for predicting real-time building energy consumption data collected by a smart grid. The proposed system integrates a seasonal autoregressive integrated moving average (SARIMA) model and metaheuristic firefly algorithm-based least squares support vector regression (MetaFA-LSSVR) model. Specifically, the proposed system fits the SARIMA model to linear data components in the first stage, and the MetaFA-LSSVR model captures nonlinear data components in the second stage. Real-time data retrieved from an experimental smart grid installed in a building were used to evaluate the efficacy and effectiveness of the proposed system. A k-week sliding window approach is proposed for employing historical data as input for the novel time-series forecasting system. The prediction system yielded high and reliable accuracy rates in 1-day-ahead predictions of building energy consumption, with a total error rate of 1.181% and mean absolute error of 0.026kWh. Notably, the system demonstrates an improved accuracy rate in the range of 36.8–113.2% relative to those of the linear forecasting model (i.e., SARIMA) and nonlinear forecasting models (i.e., LSSVR and MetaFA-LSSVR). Therefore, end users can further apply the forecasted information to enhance efficiency of energy usage in their buildings, especially during peak times. In particular, the system can potentially be scaled up for using big data framework to predict building energy consumption.

Cost-efficient one-part alkali-activated mortars with low global warming potential for floor heating systems applications

Increasing building energy efficiency is one the most cost-effective ways to reduce emissions. The use of thermal insulation materials mitigates heat loss in buildings, therefore minimising heat energy needs. In recent years, several papers were published on the subject of foam alkali-activated cements with enhanced thermal conductivity. However, on those papers cost analysis was strangely avoided. This paper presents experimental results on one-part alkali-activated cements. It also includes global warming potential assessment and cost analysis. Foam one-part alkali-activated cements cost simulations considering two carbon dioxide social costs scenarios are also included. The results show that one-part alkali-activated cements mixtures based on 26%OPC + 58.3%FA + 8%CS + 7.7%CH and 3.5% hydrogen peroxide constitute a promising cost-efficient (67 euro/m3), thermal insulation solution for floor heating systems. This mixture presents a low global warming potential of 443 KgCO2eq/m3. The results confirm that in both carbon dioxide social cost scenarios the mixture 26 OPC + 58.3 FA + 8 CS + 7.7 CH with 3.5% hydrogen peroxide foaming agent is still the most cost efficient.

Development of Foam One-Part Geopolymers with Enhanced Thermal Insulation Performance and Low Carbon Dioxide Emissions

Buildings are responsible for more than 40% of the energy consumption and greenhouse gas emissions. Thus, increasing building energy efficiency is one the most cost-effective ways to reduce emissions. The use of thermal insulation materials could constitute the most effective way of reducing heat losses in buildings by minimising heat energy needs. These materials have a thermal conductivity factor lower than 0.065 (W/m.K) while other insulation materials such as aerated concrete can go up to 0.11. Current insulation materials are associated with negative impacts in terms of toxicity. Polystyrene, for example contains anti-oxidant additives and ignition retardants. In addition, its production involves the generation of benzene and chlorofluorocarbons. Polyurethane is obtained from isocyanates, which are widely known for their tragic association with the Bhopal disaster. Besides current insulation materials releases toxic fumes when subjected to fire. This paper presents experimental results on one-part geopolymers. It also includes global warming potential assessment and cost analysis. The results show that only the use of aluminium powder allows the production mixtures with a high compressive strength however its high cost means they are commercially useless when facing the competition of commercial cellular concrete. The results also show that one-part geopolymer mixtures based on 26% Ordinary Portland Cement (OPC)+58.3% Fly Ash (FA)+8% Calcined Stuff (CS) +7.7% Calcium Hydroxide (CH) and 3.5% hydrogen peroxide constitute a promising cost efficient (67 euro/m3), thermal insulation solution for floor heating systems with low global warming potential of 443 KgCO2eq/m3.

Revitalization of Preschool Buildings: A Methodological Approach

It is generally known that a man causes changes in the environment and thus many of these changes affect the relationship between man and his environment. Additionally, population increase and urban concentration directly contribute to pollution and degradation of the environment. Considering that building construction alone represents the largest segment of energy consumption in EU (over 40%), it is logical that it has aroused the interest of scientific and professional community in terms of finding new technologies for increasing building energy efficiency and applying renewable energy sources. Satisfaction of energy demand of a country depends not only on the available energy and economic resources, but also on economic-political and energy conditions in general environment.

Energy Efficient Lighting System in Gaza Strip Buildings

This study aimed at identifying design features that can be incorporated in buildings to make them energy efficient. Energy audit and analysis is necessary to increase building energy efficiency. Three methods to increase energy efficiency were selected based on installation cost: the first method of low cost is replacing T-8 fluorescent lamps (FL) and Metal Halide lamps (ML) with T-5 and High Pressure Sodium (HPS) respectively, the second method of medium cost is replacing all FL and ML lamp with Light Emitting Diode (LED), and the third method of high cost is the automation system for room lighting based on fuzzy logic controller at some places in the building. Energy audit and analysis was performed on Irada building at Islamic University of Gaza (IUG). Good energy saving were achieved using low cost, medium cost, and high cost methods. Finally, this provided much needed power saving to be reused in Gaza Strip.

Thermally activated building systems in context of increasing building energy efficiency

One of the possible ways to provide heating to the building is to use thermally activated building systems. This type of heating, besides providing significant increase in building energy efficiency, allows using low-temperature heating sources. In this paper, special attention is given to opaque part of the building fa?ade with integrated thermally activated building systems. Due to fact that this type of system strongly depends on temperature of this construction-thermal element and type and thickness of other materials of the fa?ade, influence of these parameters on energy efficiency was analyzed in this paper. Since the simplest and most promising way of using geothermal energy is to use it directly, for our analysis this source of energy was selected. Building energy needs for heating were obtained for real residential multi-family building in Serbia by using EnergyPlus software. The building with all necessary input for simulation was modeled in Google SketchUp with aid of Open Studio Plug-in. Obtained results were compared with measured heating energy consumption. The results show that thermally activated building systems represent good way to increase building energy efficiency and that applying certain temperatures within this element, low-energy house standard can be achieved.