scholarly journals Assessment of the Effect of Phase Change Material (PCM) Glazing on the Energy Consumption and Indoor Comfort of an Office in a Semiarid Climate

2021 ◽  
Vol 11 (20) ◽  
pp. 9597
Author(s):  
Daniel Uribe ◽  
Sergio Vera
Keyword(s):  
Energy Consumption ◽  
Phase Change ◽  
Thermal Inertia ◽  
Energy Performance ◽  
Office Buildings ◽  
Visual Comfort ◽  
Meaningful Improvement ◽  
Innovative Strategy ◽  
Indoor Comfort ◽  
The Impact

Office buildings are usually characterized by low thermal inertia, which could cause underperformance in terms of energy consumption. Moreover, the use of large, glazed façades in office buildings can cause thermal and visual discomfort due to high solar heat gains and excessive daylight transmitted into the office space. Phase Change Materials (PCMs) integrated into glazing have arisen as an innovative strategy to increase thermal inertia and improve office buildings’ energy performance and indoor comfort at a low cost. This paper aims to analyze the impact of PCM glazing on buildings’ energy performance and occupants’ thermal and visual comfort. The analysis is performed through a one-year real-scale experiment in two offices in Santiago, Chile, with an east-oriented façade and a window-to-wall ratio (WWR) of 56%. The results are analyzed on two timescales: seasonally and daily. Representative days in each season were selected to carry out the analysis. Regarding the energy consumption of the HVAC system, PCM glazing reduces energy consumption during summer and mid-seasons and significantly reduces the peak loads in summer. A meaningful improvement in thermal comfort is achieved due to the control of the mean radiant temperature for the whole year. Considering visual comfort, there is an improvement in the luminance distribution in winter and mid-season cold conditions.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals Green Roofs as Effective Tools for Improving the Indoor Comfort Levels of Buildings—An Application to a Case Study in Sicily

2020 ◽  
Vol 10 (3) ◽  
pp. 893 ◽  
Author(s):  
Laura Cirrincione ◽  
Maria La Gennusa ◽  
Giorgia Peri ◽  
Gianfranco Rizzo ◽  
Gianluca Scaccianoce ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Electric Energy ◽  
Simulation Models ◽  
Green Roofs ◽  
Energy Performance ◽  
Comfort Levels ◽  
Indoor Comfort ◽  
The Impact

In the line of pursuing better energy efficiency in human activities that would result in a more sustainable utilization of resources, the building sector plays a relevant role, being responsible for almost 40% of both energy consumption and the release of pollutant substances in the atmosphere. For this purpose, techniques aimed at improving the energy performances of buildings’ envelopes are of paramount importance. Among them, green roofs are becoming increasingly popular due to their capability of reducing the (electric) energy needs for (summer) climatization of buildings, hence also positively affecting the indoor comfort levels for the occupants. Clearly, reliable tools for the modelling of these envelope components are needed, requiring the availability of suitable field data. Starting with the results of a case study designed to estimate how the adoption of green roofs on a Sicilian building could positively affect its energy performance, this paper shows the impact of this technology on indoor comfort and energy consumption, as well as on the reduction of direct and indirect CO2 emissions related to the climatization of the building. Specifically, the ceiling surface temperatures of some rooms located underneath six different types of green roofs were monitored. Subsequently, the obtained data were used as input for one of the most widely used simulation models, i.e., EnergyPlus, to evaluate the indoor comfort levels and the achievable energy demand savings of the building involved. From these field analyses, green roofs were shown to contribute to the mitigation of the indoor air temperatures, thus producing an improvement of the comfort conditions, especially in summer conditions, despite some worsening during transition periods seeming to arise.

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

scholarly journals An evaluation of the effects of thermal insulation levels on the energy performance of New Zealand office buildings- exploring the impact of building attributes on the performance of thermal insulation

2021 ◽  
Author(s):  
◽  
Brittany Grieve
Keyword(s):  
Energy Consumption ◽  
New Zealand ◽  
Thermal Insulation ◽  
Building Energy ◽  
Energy Performance ◽  
Building Envelope ◽  
Office Buildings ◽  
Building Performance ◽  
Energy Models ◽  
The Impact

<p>This thesis explored the impact of thermal insulation on the energy performance of New Zealand air-conditioned commercial office buildings. A sample of calibrated energy models constructed using real building performance data and construction information was used to ensure that the results produced were as realistic as possible to the actual building performance of New Zealand commercial office buildings. The aim was to assess how different climates and building attributes impact thermal insulation's ability to reduce energy consumption in New Zealand commercial office buildings.   Driven by the ever increasing demands for healthier, more comfortable, more sustainable buildings, building regulations have steadily increased the levels of insulation they require in new buildings over time. Improving the thermal properties of the building envelope with the addition of thermal insulation is normally used to reduce the amount of heating and cooling energy a building requires. Thermal insulation reduces the conductive heat transfer through the building envelope and with a higher level of thermal resistance, the less heat would transfer through the envelope. Consequently, the common expectation is that the addition of thermal insulation to the building envelope will always reduce energy consumption. However, this assumption is not always the case. For internal load dominated buildings located in certain climates, the presence of any or a higher level of thermal insulation may prevent heat loss through the wall, increasing the cooling energy required. This issue is thought to have not been directly examined in literature until 2008. However, an early study undertaken in New Zealand in 1996 found that for climates similar or warmer than Auckland, the addition of insulation could be detrimental to an office building's energy efficiency due to increased cooling energy requirements.  The energy performance of a sample of 13 real New Zealand office building energy models with varying levels of thermal insulation in 8 locations was examined under various scenarios. A parametric method of analysis using building energy modelling was used to assess the energy performance of the buildings. Buildings were modelled as built and standardised with the current NZS4243:2007 regulated and assumed internal load and operational values. The effect the cooling thermostat set point temperature had on the buildings' energy performance at varying levels of insulation was also tested.   The study concluded that the use of thermal insulation in New Zealand office buildings can cause an increase in cooling energy for certain types of buildings in any of the eight locations and thermal insulation levels explored in the study. The increase in cooling energy was significant enough to increase the total energy consumption of two buildings when modelled as built. These buildings were characterised by large internal loads, low performance windows with high window to wall ratios and low surface to volume ratios. The current minimum thermal resistance requirements were found to not be effective for a number of buildings in North Island locations.</p>

Impact of roof shading on building energy performance in warm & humid climatic places of India

2020 ◽  
pp. 50-64
Author(s):  
Kuladeep Kumar Sadevi ◽  
Avlokita Agrawal
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Energy Performance ◽  
General Assumption ◽  
Climatic Conditions ◽  
Building Envelope ◽  
Passive Cooling ◽  
Base Case ◽  
U Value ◽  
The Impact

With the rise in awareness of energy efficient buildings and adoption of mandatory energy conservation codes across the globe, significant change is being observed in the way the buildings are designed. With the launch of Energy Conservation Building Code (ECBC) in India, climate responsive designs and passive cooling techniques are being explored increasingly in building designs. Of all the building envelope components, roof surface has been identified as the most significant with respect to the heat gain due to the incident solar radiation on buildings, especially in tropical climatic conditions. Since ECBC specifies stringent U-Values for roof assembly, use of insulating materials is becoming popular. Along with insulation, the shading of the roof is also observed to be an important strategy for improving thermal performance of the building, especially in Warm and humid climatic conditions. This study intends to assess the impact of roof shading on building’s energy performance in comparison to that of exposed roof with insulation. A typical office building with specific geometry and schedules has been identified as base case model for this study. This building is simulated using energy modelling software ‘Design Builder’ with base case parameters as prescribed in ECBC. Further, the same building has been simulated parametrically adjusting the amount of roof insulation and roof shading simultaneously. The overall energy consumption and the envelope performance of the top floor are extracted for analysis. The results indicate that the roof shading is an effective passive cooling strategy for both naturally ventilated and air conditioned buildings in Warm and humid climates of India. It is also observed that a fully shaded roof outperforms the insulated roof as per ECBC prescription. Provision of shading over roof reduces the annual energy consumption of building in case of both insulated and uninsulated roofs. However, the impact is higher for uninsulated roofs (U-Value of 3.933 W/m2K), being 4.18% as compared to 0.59% for insulated roofs (U-Value of 0.33 W/m2K).While the general assumption is that roof insulation helps in reducing the energy consumption in tropical buildings, it is observed to be the other way when insulation is provided with roof shading. It is due to restricted heat loss during night.

Evaluation the effect of the ambient temperature on the liquid petroleum gas transportation pipeline

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ammar Ali Abd ◽  
Samah Zaki Naji ◽  
Ching Thian Tye ◽  
Mohd Roslee Othman
Keyword(s):  
Energy Consumption ◽  
Greenhouse Gases ◽  
Ambient Temperature ◽  
Phase Change ◽  
Liquid State ◽  
Pump Energy ◽  
Compressible Liquid ◽  
Liquefied Petroleum Gas ◽  
Efficient Design ◽  
The Impact

Abstract Liquefied petroleum gas (LPG) plays a major role in worldwide energy consumption as a clean source of energy with low greenhouse gases emission. LPG transportation is exhibited through networks of pipelines, maritime, and tracks. LPG transmission using pipeline is environmentally friendly owing to the low greenhouse gases emission and low energy requirements. This work is a comprehensive evaluation of transportation petroleum gas in liquid state and compressible liquid state concerning LPG density, temperature and pressure, flow velocity, and pump energy consumption under the impact of different ambient temperatures. Inevitably, the pipeline surface exchanges heat between LPG and surrounding soil owing to the temperature difference and change in elevation. To prevent phase change, it is important to pay attention for several parameters such as ambient temperature, thermal conductivity of pipeline materials, soil type, and change in elevation for safe, reliable, and economic transportation. Transporting LPG at high pressure requests smaller pipeline size and consumes less energy for pumps due to its higher density. Also, LPG transportation under moderate or low pressure is more likely exposed to phase change, thus more thermal insulation and pressure boosting stations required to maintain the phase envelope. The models developed in this work aim to advance the existing knowledge and serve as a guide for efficient design by underling the importance of the mentioned parameters.

Recommended angle of a modular dynamic façade in hot-arid climate: daylighting and energy simulation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Seyedeh Samaneh Golzan ◽  
Mina Pouyanmehr ◽  
Hassan Sadeghi Naeini
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Energy Performance ◽  
Arid Climate ◽  
Visual Comfort ◽  
Building Envelopes ◽  
Content Type ◽  
Optimum Angle ◽  
Energy Efficient Buildings ◽  
Hot Arid Climate

PurposeThe modular dynamic façade (MDF) concept could be an approach in a comfort-centric design through proper integration with energy-efficient buildings. This study focuses on obtaining and/or calculating an efficient angle of the MDF, which would lead to the optimum performance in daylight availability and energy consumption in a single south-faced official space located in the hot-arid climate of Yazd, Iran.Design/methodology/approachThe methodology consists of three fundamental parts: (1) based on previous related studies, a diamond-based dynamic skin façade was applied to a south-faced office building in a hot-arid climate; (2) the daylighting and energy performance of the model were simulated annually; and (3) the data obtained from the simulation were compared to reach the optimum angle of the MDF.FindingsThe results showed that when the angle of the MDF openings was set at 30°, it could decrease energy consumption by 41.32% annually, while daylight simulation pointed that the space experienced the minimum possible glare at this angle. Therefore, the angle of 30° was established as the optimum angle, which could be the basis for future investment in responsive building envelopes.Originality/valueThis angular study simultaneously assesses the daylight availability, visual comfort and energy consumption on a MDF in a hot-arid climate.

scholarly journals Intelligent Energy Management Strategy for Automated Office Buildings

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4326 ◽  
Author(s):  
Simplice Igor Noubissie Tientcheu ◽  
Shyama P. Chowdhury ◽  
Thomas O. Olwal
Keyword(s):  
Energy Consumption ◽  
Intelligent System ◽  
Weather Condition ◽  
Electrical Energy ◽  
Integrated System ◽  
Office Buildings ◽  
Photovoltaic System ◽  
Energy Management Strategy ◽  
Significant Saving ◽  
The Impact

The increasing demand to reduce the high consumption of end-use energy in office buildings framed the objective of this work, which was to design an intelligent system management that could be utilized to minimize office buildings’ energy consumption from the national electricity grid. Heating, Ventilation and Air Conditioning (HVAC) and lighting are the two main consumers of electricity in office buildings. Advanced automation and control systems for buildings and their components have been developed by researchers to achieve low energy consumption in office buildings without considering integrating the load consumed and the Photovoltaic system (PV) input to the controller. This study investigated the use of PV to power the HVAC and lighting equipped with a suitable control strategy to improve energy saving within a building, especially in office buildings where there are reports of high misuse of electricity. The intelligent system was modelled using occupant activities, weather condition changes, load consumed and PV energy changes, as input to the control system of lighting and HVAC. The model was verified and tested using specialized simulation tools (Simulink®) and was subsequently used to investigate the impact of an integrated system on energy consumption, based on three scenarios. In addition, the direct impact on reduced energy cost was also analysed. The first scenario was tested in simulation of four offices building in a civil building in South Africa of a single occupant’s activities, weather conditions, temperature and the simulation resulted in savings of HVAC energy and lighting energy of 13% and 29%, respectively. In the second scenario, the four offices were tested in simulation due to the loads’ management plus temperature and occupancy and it resulted in a saving of 20% of HVAC energy and 29% of lighting electrical energy. The third scenario, which tested integrating PV energy (thus, the approach utilized) with the above-mentioned scenarios, resulted in, respectively, 64% and 73% of HVAC energy and lighting electrical energy saved. This saving was greater than that of the first two scenarios. The results of the system developed demonstrated that the loads’ control and the PV integration combined with the occupancy, weather and temperature control, could lead to a significant saving of energy within office buildings.

scholarly journals Energy Conservation Potential of Economizer Controls Using Optimal Outdoor Air Fraction Based on Field Study

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5038
Author(s):  
Goopyo Hong ◽  
Chul Kim ◽  
Jun Hong
Keyword(s):  
Energy Consumption ◽  
Energy Conservation ◽  
Temperature Control ◽  
Energy Savings ◽  
Cooling System ◽  
Energy Performance ◽  
Outdoor Air ◽  
Humid Climate ◽  
Differential Enthalpy ◽  
The Impact

In commercial buildings, HVAC systems are becoming a primary driver of energy consumption, which already account for 45% of the total building energy consumption. In the previous literature, researchers have studied several energy conservation measures to reduce HVAC system energy consumption. One of the effective ways is an economizer in air-handling units. Therefore, this study quantified the impact of the outdoor air fraction by economizer control type in cooling system loads based on actual air-handling unit operation data in a hospital. The optimal outdoor air fraction and energy performance for economizer control types were calculated and analyzed. The result showed that economizer controls using optimal outdoor air fraction were up to 45% more efficient in cooling loads than existing HVAC operations in the hospital. The energy savings potential was 6–14% of the differential dry-bulb temperature control, 17–27% of the differential enthalpy control, 8–17% of the differential dry-bulb temperature and high-limit differential enthalpy control, and 16–27% of the differential enthalpy and high-limit differential dry-bulb temperature control compared to the no economizer control. The result of this study will contribute to providing a better understanding of economizer controls in the hospital when the building operates in hot-humid climate regions.

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