03/02411 Energy performance of the self-shading building envelope

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.

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Energy Performance of a High-Rise Residential Building Using Fibre-Reinforced Structural Lightweight Aggregate Concrete

Applied Sciences ◽

10.3390/app10134489 ◽

2020 ◽

Vol 10 (13) ◽

pp. 4489

Author(s):

Zakaria Che Muda ◽

Payam Shafigh ◽

Norhayati Binti Mahyuddin ◽

Samad M.E. Sepasgozar ◽

Salmia Beddu ◽

...

Keyword(s):

Residential Building ◽

Green Building ◽

Lightweight Aggregate ◽

Energy Performance ◽

Building Envelope ◽

Lightweight Aggregate Concrete ◽

Aggregate Concrete ◽

High Rise ◽

Passive Design ◽

Envelope Material

The increasing need for eco-friendly green building and creative passive design technology in response to climatic change and global warming issues will continue. However, the need to preserve and sustain the natural environment is also crucial. A building envelope plays a pivotal role in areas where the greatest heat and energy loss often occur. Investment for the passive design aspect of building envelopes is essential to address CO 2 emission. This research aims to explore the suitability of using integral-monolithic structural insulation fibre-reinforced lightweight aggregate concrete (LWAC) without additional insulation as a building envelope material in a high-rise residential building in the different climatic zones of the world. Polypropylene and steel fibres in different dosages were used in a structural grade expanded clay lightweight aggregate concrete. Physical and thermal properties of fibre reinforced structural LWAC, normal weight concrete (NWC) and bricks were measured in the lab. The Autodesk@Revit-GBS simulation program was implemented to simulate the energy consumption of a 29-storey residential building with shear wall structural system using the proposed fibre-reinforced LWAC materials. Results showed that energy savings between 3.2% and 14.8% were incurred in buildings using the fibre-reinforced LWAC across various climatic regions as compared with traditional NWC and sand-cement brick and clay brick walls. In conclusion, fibre-reinforced LWAC in hot-humid tropical and temperate Mediterranean climates meet the certified Green Building Index (GBI) requirements of less than 150 kW∙h∙m−2. However, in extreme climatic conditions of sub-arctic and hot semi-arid desert climates, a thicker wall or additional insulation is required to meet the certified green building requirements. Hence, the energy-saving measure is influenced largely by the use of fibre-reinforced LWAC as a building envelope material rather than because of building orientation.

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The determination of the thermal reliability criterion for building envelope structures

Tehnički glasnik ◽

10.31803/tg-20181123111226 ◽

2019 ◽

Vol 13 (2) ◽

pp. 129-133

Author(s):

Gennadiy Farenyuk

Keyword(s):

Thermal Insulation ◽

Building Energy ◽

Energy Performance ◽

Building Envelope ◽

Time Analysis ◽

Thermal Reliability ◽

Thermal Failure ◽

Reliability Criterion ◽

Building Operation

The paper presents the basic methodical principles for the time analysis of the variations of envelope structures’ thermal insulation properties and for the substantiation of the thermal reliability criterion, which should allow the analysis of the actual parameters of heat losses during the operation of buildings. In the paper, the state of the envelope structures thermal failure, the concept of building thermal envelope thermal reliability and the principles of its rating are defined. The physical meaning and basic criterion of the envelope structure thermal reliability are formulated. The application of the thermal reliability criterion allows determining the probable variations in the thermal insulation properties during the building operation and, accordingly, the changes of the building energy performance over time.

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Experimental Study on the Thermal Behavior of Exterior Coating Textures of Building in Hot and Arid Climates

Sustainability ◽

10.3390/su13084175 ◽

2021 ◽

Vol 13 (8) ◽

pp. 4175

Author(s):

Islam Boukhelkhal ◽

Fatiha Bourbia

Keyword(s):

Energy Consumption ◽

Surface Temperature ◽

External Surface ◽

Thermal Characteristics ◽

Energy Performance ◽

Building Envelope ◽

Interior Space ◽

Design Elements ◽

Aesthetic Appearance ◽

Reduction Of Energy Consumption

The building envelope is the barrier between the interior and exterior environments. It has many important functions, including protecting the interior space from the climatic variations through its envelope materials and design elements, as well as reduction of energy consumption and improving indoor thermal comfort. Furthermore, exterior building sidings, in addition to their aesthetic appearance, can have useful textures for reducing solar gains and providing good thermal insulation performance. This research examined and evaluated the effect of external siding texture and geometry on energy performance. For this objective, a field in situ testing and investigation of surface temperature was carried out on four samples (test boxes) with different exterior textures and different orientations, under the climate zone of Constantine–Algeria during the summer period. The results indicated significant dependability between the exterior texture geometry, the percentage of shadow projected, and external surface temperature. The second part of the research involved a similar approach, exploring the effect of three types of particles with the same appearance but with different thermal characteristics. It was concluded that the natural plant aggregates “palm particles” had the best performance, which contributed to a significant reduction of external surface temperature reaching 4.3 °C, which meant decreasing the energy consumption.

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Energy Saving Technology for Doors and Windows of the Building

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1056.128 ◽

2014 ◽

Vol 1056 ◽

pp. 128-130

Author(s):

Fu Yun Yang

Keyword(s):

Energy Saving ◽

Indoor Environment ◽

Energy Performance ◽

Building Envelope ◽

Energy Performance Of Buildings ◽

Summer Heat ◽

Energy Saving Technology ◽

Heat Preservation

Doors and windows of the building is an important part of the building envelope. AS the transparent and open envelope of the building, doors and windowsare the weakest part in the winter and summer heat preservation. It directly affects the energy performance of buildings. Therefore, do a good job of building doors and windows energy saving is an important way to optimize the indoor environment and realize energy saving.

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Redefining cost-optimal nZEB levels for new residential buildings

E3S Web of Conferences ◽

10.1051/e3sconf/201911103035 ◽

2019 ◽

Vol 111 ◽

pp. 03035 ◽

Cited By ~ 2

Author(s):

Raimo Simson ◽

Endrik Arumägi ◽

Kalle Kuusk ◽

Jarek Kurnitski

Keyword(s):

Energy Use ◽

Net Present Value ◽

Residential Buildings ◽

Energy Performance ◽

Optimal Level ◽

Building Envelope ◽

Simulation Software ◽

The European Union ◽

Apartment Building ◽

Detached House

In the member states of the European Union (EU), nearly-Zero Energy Buildings (nZEB) are becoming mandatory building practice in 2021. It is stated, that nZEB should be cost-optimal and the energy performance levels should be re-defined after every five years. We conducted cost-optimality analyses for two detached houses, one terraced house and one apartment building in Estonia. The analysis consisted on actual construction cost data collection based on bids of variable solutions for building envelope, air tightness, windows, heat supply systems and local renewable energy production options. For energy performance analysis we used dynamic simulation software IDA-ICE. To assess cost-effectiveness, we used Net Present Value (NPV) calculations with the assessment period of 30 years. The results for cost-optimal energy performance level for detached house with heated space of ~100 m2 was 79 kWh/(m2 a), for the larger house (~200 m2) 87 kWh/(m2 a), for terraced house with heated space of ~600 m2 71 kWh/(m2 a) and for the apartment building 103 kWh/(m2 a) of primary energy including all energy use with domestic appliances. Thus, the decrease in cost-optimal level in a five-year period was ~60% for the detached house and ~40% for the apartment building, corresponding to a shift in two EPC classes.

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BIM and BEM Methodologies Integration in Energy-Efficient Buildings Using Experimental Design

Buildings ◽

10.3390/buildings11100491 ◽

2021 ◽

Vol 11 (10) ◽

pp. 491

Author(s):

Jorge González ◽

Carlos Alberto Pereira Soares ◽

Mohammad Najjar ◽

Assed N. Haddad

Keyword(s):

Experimental Design ◽

Energy Efficient ◽

Thermal Characteristics ◽

Energy Performance ◽

Building Envelope ◽

Climatic Zones ◽

Energy Efficient Buildings ◽

Energy Modelling ◽

Building Information ◽

Energetic Performance

Linking Building Information Modelling and Building Energy Modelling methodologies appear as a tool for the energy performance analysis of a dwelling, being able to build the physical model via Autodesk Revit and simulating the energy modeling with its complement Autodesk Insight. A residential two-story house was evaluated in five different locations within distinct climatic zones to reduce its electricity demand. Experimental Design is used as a methodological tool to define the possible arrangement of results emitted via Autodesk Insight that exhibits the minor electric demand, considering three variables: Lighting efficiency, Plug-Load Efficiency, and HVAC systems. The analysis concluded that while the higher the efficiency of lighting and applications, the lower the electric demand. In addition, the type of climate and thermal characteristics of the materials that conform to the building envelope have significant effects on the energetic performance. The adjustment of different energetic measures and its comparison with other climatic zones enable decision-makers to choose the best combination of variables for developing strategies to lower the electric demand towards energy-efficient buildings.

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Application of Urban Scale Energy Modelling and Multi-Objective Optimization Techniques for Building Energy Renovation at District Scale

Sustainability ◽

10.3390/su132011554 ◽

2021 ◽

Vol 13 (20) ◽

pp. 11554

Author(s):

Fahad Haneef ◽

Giovanni Pernigotto ◽

Andrea Gasparella ◽

Jérôme Henri Kämpf

Keyword(s):

Energy Efficiency ◽

Building Energy ◽

Energy Performance ◽

Building Envelope ◽

Optimization Techniques ◽

Multi Objective Optimization ◽

Building Stock ◽

Energy Efficiency Measures ◽

Multi Objective ◽

Efficiency Measures

Nearly-zero energy buildings are now a standard for new constructions. However, the real challenge for a decarbonized society relies in the renovation of the existing building stock, selecting energy efficiency measures considering not only the energy performance but also the economic and sustainability ones. Even if the literature is full of examples coupling building energy simulation with multi-objective optimization for the identification of the best measures, the adoption of such approaches is still limited for district and urban scale simulation, often because of lack of complete data inputs and high computational requirements. In this research, a new methodology is proposed, combining the detailed geometric characterization of urban simulation tools with the simplification provided by “building archetype” modeling, in order to ensure the development of robust models for the multi-objective optimization of retrofit interventions at district scale. Using CitySim as an urban scale energy modeling tool, a residential district built in the 1990s in Bolzano, Italy, was studied. Different sets of renovation measures for the building envelope and three objectives —i.e., energy, economic and sustainability performances, were compared. Despite energy savings from 29 to 46%, energy efficiency measures applied just to the building envelope were found insufficient to meet the carbon neutrality goals without interventions to the system, in particular considering mechanical ventilation with heat recovery. Furthermore, public subsidization has been revealed to be necessary, since none of the proposed measures is able to pay back the initial investment for this case study.

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Refurbishment of a house in a historical building: energy saving, electrification and flexibility

E3S Web of Conferences ◽

10.1051/e3sconf/202019702010 ◽

2020 ◽

Vol 197 ◽

pp. 02010

Author(s):

Giada Romano ◽

Elisa Pennacchia ◽

Sofia Agostinelli

Keyword(s):

Energy Efficiency ◽

Renewable Energy ◽

Energy Saving ◽

Renewable Energy Sources ◽

Energy Performance ◽

Building Envelope ◽

Energy Sources ◽

Automation Systems ◽

Architectural Constraints ◽

Current Energy

Buildings with architectural constraints and recognized historical values require a careful design process, aiming to combine the needs of conservation and the adaptation of the buildings to the modern use and its accessibility. The feasible interventions consist in improving the energy performance of the building envelope, in inserting efficient technological systems and using renewable energy sources where possible. The compatibility between the architectural constraints of the building and its more sustainable future use represents a crucial challenge. This work presents the interventions designed and realized on a small villa located in the Prati district, in Rome. Starting from the requests of the client, the primary objective was to create a comfortable house both in the winter and in the summer season, with widespread use of automation systems for managing the utilities. In line with the current energy scenario, the interventions were oriented to energy efficiency, the reduction of polluting emissions, the electrification of utilities and the use of renewable energy sources. The proposed solutions showed high gains in terms of energy saving even if the changes to the building envelope were limited by the desire to preserve the values of the cultural heritage. Therefore, a virtuous refurbishment can effectively respond to current energy efficiency goals.

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