A Study on the Energy Performance Evaluation of a Smart Skin for Reducing Cooling Load of Building Envelope in Office Building

The narrow land in big cities such as Jakarta, increases the amount of high rise building, especially multi-storey office building. Office building consumes much energy to provide air conditioning to meet the thermal comfort inside the building. On the other hand, the building shape, building envelope, and building orientation to the sun's position are the main factors in building design aspects that affect the amount of cooling load. This study aims to investigate the impact of the aspect ratio or the ratio of the longer dimension of an oblong plan to the shorter, on external heat gain of multi-storey office building. Variables examined include the transparent and solid area of building envelope, the total area of the surface of the building envelope in any orientation, and the volume of the building, as well as the influence of those proportion on the external heat gain. This study uses mathematical calculations to predict the cooling load of the building, particularly external heat gain through the walls, roof and glass, as well as comparative analysis of models studied. The study also aims to generate the design criteria of building form and proportion of multi-storey office buildings envelope with lower external heat gain. In Jakarta climatic conditions, the result on rectangular building plan with aspect ratio of 1 to 4 shows that the external heat gain did not differ significantly, and the smallest heat gain is found on the aspect ratio of 1.8. Results also showed that the greater aspect ratio, the greater reduction of external heat gain obtained by changing the orientation of the longest side facing east-west into the north-south, about 2.79% up to 42.14% on the aspect ratio of 1.1 to 4. In addition, it is known that in same building volume, changing the number of floors from 10 to 50 can improve the external heat gain almost twice.

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Transformation of an Office Building into a Nearly Zero Energy Building (nZEB): Implications for Thermal and Visual Comfort and Energy Performance

Energies ◽

10.3390/en12050895 ◽

2019 ◽

Vol 12 (5) ◽

pp. 895 ◽

Cited By ~ 14

Author(s):

Ilaria Ballarini ◽

Giovanna De Luca ◽

Argun Paragamyan ◽

Anna Pellegrino ◽

Vincenzo Corrado

Keyword(s):

Thermal Comfort ◽

Energy Savings ◽

Energy Performance ◽

Primary Energy ◽

Building Envelope ◽

Office Building ◽

Indoor Environmental Quality ◽

Visual Comfort ◽

Zero Energy ◽

Efficiency Measures

Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.

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Effect of Operating Temperatures on Thermal Conductivity of Polystyrene Insulation Material: Impact on Envelope-Induced Cooling Load

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.564.315 ◽

2014 ◽

Vol 564 ◽

pp. 315-320 ◽

Cited By ~ 8

Author(s):

Maatouk Khoukhi ◽

Mahmoud Tahat

Keyword(s):

Thermal Conductivity ◽

Thermal Insulation ◽

Energy Performance ◽

Building Envelope ◽

Insulation Material ◽

Cooling Load ◽

Thermal Insulation Material ◽

Insulation Materials ◽

Energy Performance Of Buildings ◽

The Impact

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.

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ESTIMATING ENERGY SAVING POTENTIAL BY TAKING INTO ACCOUNT INTERDEPENDENCE EFFECT CASE STUDY: HIGH RISE OFFICE BUILDING IN JAKARTA

JURNAL INOVASI PENDIDIKAN DAN SAINS ◽

10.51673/jips.v2i1.476 ◽

2021 ◽

Vol 2 (1) ◽

pp. 26-32

Author(s):

Endang Widayati

Keyword(s):

Energy Saving ◽

Energy Performance ◽

Office Building ◽

Cooling Load ◽

Energy Saving Potential ◽

High Rise

Abstrak: Tujuan studi ini adalah membandingkan perhitungan potensi penghematan energi tanpa memperhitungkan efek interdepensi dengan perhitungan potensi penghematan energi dengan memperhitungkan efek interdependensi berdasarkan studi kasus pada bangunan gedung terkondisikan. Estimasi potensi penghematan energi yang akurat akan menghasilkan proyek konservasi dan efisiensi energi yang bankable akan meningkatkan kepercayaan terhadap investasi proyek – proyek penghematan energi. Hal ini akan meminimalkan ketidakpastian penghematan energi yang dapat dicapai serta meningkatkan potensi untuk mencegah risiko investasi dari implementasi proyek – proyek konservasi dan efisiensi energi. Hasil dari studi ini menunjukkan bahwa terjadi kenaikan estimasi penghematan energi sebesar 4,29% pada ESM-1 yaitu retrofit tata cahaya dan kenaikan estimasi penghematan energi sebesar 22,75% pada ESM-2 yaitu pemasangan VSD pada AHU. Pengaruh interdependensi tersebut adalah adanya pengurangan cooling load pada bangunan gedung karena efek interdependensi pada ESM-1 dan ESM -2. Secara total perhitungan efek interdependensi akan meningkatkan prosentase total estimasi potensi penghematan energi dari 34.23% menjadi 39,05% berdasarkan baseline energi dengan baseyear yang telah ditetapkan atau meningkat sebesar 4,82%. Perhitungan efek interdependensi akan sangat berpengaruh untuk meminimalisasi ketidakpastian apabila proyek proyek konservasi dan efisiensi energi dibiayai dengan energy performance contract dengan skema guaranteed saving maupung shared saving. Perlu tindak lanjut dari studi ini yaitu perhitungan dan verfifikasi penghematan energi hasil implementasi ESM-1, ESM-2 dan ESM-3 pada tahun berjalan.

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Impact of orientation and building envelope characteristics on energy consumption case study of office building in city of Nis

Thermal Science ◽

10.2298/tsci18s5499v ◽

2018 ◽

Vol 22 (Suppl. 5) ◽

pp. 1499-1509

Author(s):

Miomir Vasov ◽

Jelena Stevanovic ◽

Veliborka Bogdanovic ◽

Marko Ignjatovic ◽

Dusan Randjelovic

Keyword(s):

Energy Consumption ◽

Early Stage ◽

Building Energy ◽

Energy Performance ◽

Building Envelope ◽

Office Building ◽

Climatic Data ◽

Building Energy Efficiency ◽

Maximum Difference ◽

Heating And Cooling

Buildings are one of the biggest energy consumers in urban environments, so its efficient use represents a constant challenge. In public objects and households, a large part of the energy is used for heating and cooling. The orientation of the object, as well as the overall heat transfer coefficient (U-value) of transparent and non-transparent parts of the envelope, can have a significant impact on building energy needs. In this paper, analysis of the influence of different orientations, U-values of envelope elements, and size of windows on annual heating and cooling energy for an office building in city of Nis, Serbia, is presented. Model of the building was made in the Google SketchUp software, while the results of energy performance were obtained using EnergyPlus and jEplus, taking into ac-count the parameters of thermal comfort and climatic data for the area of city of Nis. Obtained results showed that, for varied parameters, the maximum difference in annual heating energy is 15129.4 kWh, i. e per m2 27.75 kWh/m2, while the maximum difference in annual cooling energy is 14356.1 kWh, i. e per m2 26.33 kWh/m2. Considering that differences in energy consumption are significant, analysis of these parameters in the early stage of design process can affect on increase of building energy efficiency.

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Comparison between Energy Simulation and Monitoring Data in an Office Building

Energies ◽

10.3390/en15010239 ◽

2021 ◽

Vol 15 (1) ◽

pp. 239

Author(s):

Koldobika Martin-Escudero ◽

Garazi Atxalandabaso ◽

Aitor Erkoreka ◽

Amaia Uriarte ◽

Matteo Porta

Keyword(s):

Building Energy ◽

Energy Performance ◽

Building Envelope ◽

Energy Simulation ◽

Office Building ◽

Mean Bias Error ◽

Bias Error ◽

Data Sets ◽

Hourly Basis ◽

Good Agreement

One of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).

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A Case Study on the Verification of Passive Office Energy Performance Comparing Actual Energy Consumption to Simulation Result

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.361-363.427 ◽

2013 ◽

Vol 361-363 ◽

pp. 427-430 ◽

Cited By ~ 1

Author(s):

Young Sun Ko ◽

Sang Tae No

Keyword(s):

Energy Consumption ◽

Energy Performance ◽

Building Envelope ◽

Office Building ◽

Simulation Accuracy ◽

Existing Building ◽

Heating And Cooling ◽

Insulation Thickness ◽

Actual Energy Consumption ◽

Heating And Cooling Load

The objective of this study is to verify energy performance of passive office building compared to existing building using computer simulation tool, EnergyPlus. S building was selected as a passive office building, which is the first passive office building in KOREA, and the building satisfy the passive house standard. The annual energy consumption data were compared to the heating and cooling load result of EnergyPlus, to verify simulation accuracy. The conditions of existing building were selected from Korean envelope standard and the categories of the conditions are the insulation thickness and glazing composition. As a result, the passive office showed 28% reduced energy consumption, compared to the existing building, with ordinary envelope under Korean building envelope standard.

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Improving Building Energy Performance Using Dual VAV Configuration Integrated with Dedicated Outdoor Air System

Buildings ◽

10.3390/buildings11100466 ◽

2021 ◽

Vol 11 (10) ◽

pp. 466

Author(s):

Nabil Nassif ◽

Iffat Ridwana

Keyword(s):

Energy Consumption ◽

Air Temperature ◽

Energy Savings ◽

Energy Performance ◽

Office Building ◽

Effective Control ◽

Cooling Load ◽

Outdoor Air ◽

System A ◽

Cooling Loads

As building systems account for almost half of the total energy consumed by the building sector to provide space heating, cooling, and ventilation, efficiently designing these systems can be the key to energy conservation in buildings. Dual VAV systems with an effective control strategy can substantially reduce the energy consumption in buildings, providing a significant scope of further research on this system configuration. This paper proposes to utilize the warm air duct of the dual VAV system as a dedicated outdoor air (DOA) unit when no heating is required, which allows the cooling load to be effectively distributed between two ducts. A specific control sequence is proposed with different supply air temperature reset strategies to estimate the heating, cooling loads, and fan power energy consumption of the proposed system. A simple two-zone office building is taken as a preliminary case study to simulate the airflow rates and fan power of a single duct VAV and proposed dual VAV systems to illustrate the concept. Finally, a larger multi-zone office building is simulated to measure the annual heating, cooling loads, and fan power energy and compare the energy savings among the systems. The results show significant fan power reduction ranging from 1.7 to 9% and notable heating energy reduction up to 76.5% with a small amount of cooling load reduction varying from 0.76 to 2.56% depending on the different locations for the proposed dual VAV systems. Further energy savings from different supply air temperature reset strategies demonstrate the opportunity of employing them according to climates and case studies. The proposed dual VAV system proves to have the potential to be adapted in buildings for the purpose of sustainability and energy savings.

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Energy performance modelling and heat recovery unit efficiency assessment of an office building

Thermal Science ◽

10.2298/tsci140311102h ◽

2015 ◽

Vol 19 (3) ◽

pp. 865-880 ◽

Cited By ~ 3

Author(s):

Norbert Harmati ◽

Radomir Folic ◽

Zoltán Magyar

Keyword(s):

Energy Demand ◽

Energy Performance ◽

Building Envelope ◽

Office Building ◽

Hvac System ◽

Analysis Model ◽

Case Scenario ◽

Performance Modelling ◽

Heating And Cooling ◽

Simulation Engine

This paper investigates and analyzes a typical multi-zone office building?s annual energy performance for the location and climate data of central Belgrade. The aim is to evaluate the HVAC system?s and HR unit?s performance in order to conduct the most preferable heating and cooling solution for the typical climate of Belgrade city. The energy performance of four HVAC system types (heat pump - air to air, gas-electricity, electrical and fan coil system) was analyzed, compared and evaluated on a virtual office building model in order to assess the total annual energy performance and to determine the efficiency of the HR unit?s application. Further, the parameters of an energy efficient building envelope, HVAC system, internal loads, building operation schedules and occupancy intervals were implemented into the multi-zone analysis model. The investigation was conducted in EnergyPlus simulation engine using system thermodynamic algorithms and surface/air heat balance modules. The comparison and evaluation of the obtained results was achieved through the conversion of the calculated total energy demand into primary energy. The goal is conduct the most preferable heating and cooling solution (Best Case Scenario) for the climate of Belgrade city and outline major criteria in qualitative enhancement.

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