Upgrade to NZEB: Commercial Building in Warm and Humid Climate, India

SEMINAR

UPGRADE TO NZEB: Commercial Building in Warm and Humid Climate, India

BY

RAUNAKMOHAPATRA (183701072)

SAMARPITASINHARAY (183701120)

MSAP, MAHE

CONTENTS

1 2 3 4 5 6 7 8 9

ABSTRACTANDOUTLINE

INTRODUCTIONANDRELEVANCE

LITERATURESTUDYANDSTUDYPARAMETERS

RESEARCHGAPANDQUESTIOINS

AIM&OBJECTIVES

RESEARCHMETHODOLOGY

LITERATUREREVIEW&MATRIXFORMULATION

DATACOLLECTION

REFERNCES

INTRODUCTION

The notion of a Net Zero Energy Building (NZEB), a structure that produces as much energy as it consumes over the course of a year, has lately progressed from concept to reality. There are currently only a few very efficient buildings that meet the criterion for being labelled "Net Zero."

GLOBAL STANDARD

Key requirements of the Global Net-Zero Standard

1. Focus on rapid, deep emission cuts

2. Set near- and long-term targets:

3. No net-zero claims until long-term targets are met:

4. Go beyond the value chain:

If a net zero energy building consumes only as much renewable energy as it generates on-site, a net zero energy community, or state, produces all of the energy it consumes cleanly on-site, or locally.

INDIA AND NZEB

➢ India is the world's fourth largest carbon dioxide emitter.

CRITERIA

Regardless of the criteria or metric for a Net Zero Energy Building, reducing energy consumption through efficient building design should be a core design objective and the highest focus of all NZEB projects.

Energy efficiency is typically the most cost-effective method with the highest return on investment, and optimising efficiency potential before establishing renewable energy plans will reduce the cost of the renewable energy projects that are required.

➢ In 2019, India released 1.9 tonnes of CO2 per person, compared to 15.5 tonnes for the United States and 12.5 tonnes for Russia.

➢ India declined to set targets ahead of the adoption of the 2015 Paris Agreement

EXISTING BUILDINGS AND NZEB

➢ Existing Buildings are on the radar of certain guides that have loose interpretations of targets for NZEB.

➢ The Bureau of Energy Efficiency (BEE) Guide- Existing Buildings To Nearly Zero Energy Buildings (nZEB) is one of them, but these aren’t specific to technologies and design strategies that one may interpret easily. The main aim is to close this gap.

➢ Net zero energy building is a method of designing to achieve energy efficiency through grid-connected building and other building features.

➢ The building form, envelop and design components also play a big role on reducing the energy demand. They can also be called zero-energy building because of the net annual energy consumption being zero.

➢ Net Zero Buildings have less EUI in comparison with the other conventional buildings as they reduce their energy demands by using energy efficient technologies and materials.

Different design principles can be developed along the following variables:

LIGHTING GUIDELINES

➢ There are two classifications based on energy generation under Net Zero Building: ▪

NearlyNetZeroBuildings

▪ PositiveNetZeroBuildings

➢ Decision makers need to be aware of the fundamental building principles to be adopted and the technologies available at their disposal.

➢ The basic guidelines of net zero energy buildings include the following principles/ technology through which one can achieve building energy neutrality.

EFFICIENT EQUIPMENTS RENEWABLE ENERGY

The different techniques through which the variables are incorporated: ACTIVE PASSIVE

India plans to reach its Net Zero Targets by 2070. The Commercial Building Sector of India is expected to grow in such a way that by 2030, 50% of India’s commercial buildings will have been newly constructed from 2020.

• What are the most efficient techniques to achieve NZEB in existing office building in India?

• Which of these techniques best cater to warm and humid climate?

• This is a massive step towards using sustainable methods in commercial buildings, which would generously contribute to NZEB goals.

• However, the big void, which is the existing buildings needs to be addressed, in order to truly sustain them to suit the future architectural environment.

Research Gap

• There is a gap found in availability of specific guideline for energy efficient methods in warm and humid climate in India, that can be used to achieve Net Zero Energy Building

• What parameters must be the basis to identify such techniques?

Research Questions

• To study about the NZEB concept and identify different variable associated with it.

SCOPE

❑ The study will focus on existing office building and discusses strategies that can be used to retrofit same.

❑ The strategies selected will be catering to warm and humid climate in India.

• To identify efficient technologies to attain net zero energy

❑ According the case studies for the study will be selected and evaluation will be done.

• To analyse these variables and identify techniques suitable for warm and humid climate

LIMITATIONS

• To determine the guidelines for techniques that can be used to retrofit commercial building in warm and humid climate in India

❑ The research will be exploring only on retrofitting guidelines that can be used in commercial buildings

❑ And it only applies to the context chosen. Other climatic considerations are not taken

Objectives

TO IDENTIFY EFFICIENTAND FEASIBLE TECHNIQUES TO ACHIEVE NZEB IN EXISTING INDIAN COMMERCIAL BUILDING IN WARM AND HUMID CLIMATE

After identification of gap, establishing objectives and setting the constraints of the study, the methodology of the study has been developed to derive a detailed guideline for the strategies that can be used to retrofit a commercial building to make it Net Zero Energy.

METHODOLOGY

Literature study on NZEB: understanding different variables for net zero energy building

Obtaining the variables to form a matrix for analysis, in terms of the techniques and components

UNDERSTANDING NET ZERO ENERGY AND DIFFERENT WAYS TO ACHIEVE SAME

Systematic literature review on different papers related to NZEB, to find out strategies used in retrofitting buildings

IDENTIFYING THE VARIABLES FOR APPLICATION

FORM MATRIX

Doing case studies on Net Zero energy projects in warm and humid climate to understand the strategies used

IDENTIFYING DIFFERENT TECHNIQUES

LITERATURE STUDY CASE STUDY

Analyse these strategies in terms of its feasibility and deriving the best techniques for warm and humid climate

IDENTIFY THE EFFICIENT STRATEGIES ACCORDING TO SCOPE MENTIONED

Target: produce a matrix with the variable that will work as a guideline for the commercial building typology

Research Methodology

FORM GUIDELINES ACCORDING TO FEASIILITY OF THE TECHNIQUES USED TO ACHIEVE NZEB

Title of Paper Factors Considered for Study Purpose of the Study Outcomes and Findings

1 Nearly-zero energy buildings: retrofitting to meet the standard Yijun Fu, Shicong Zhang, Xi ChenWei Xu

Case Studies- Building Profile, Heating, Cooling, Domestic Hot Water, Weather Data, Orientation, Weather Data

To demonstrate the potential benefits but also highlight the risks associated with achieving such high energy efficiency standards within the built environment

Inference/Research Gap

2 Design guidelines for Net Zero Energy Building (NZEB) in Warm and Humid Climate of India

Climate Analysis, Rating Codes in India, Passive Strategies, Case Studies

To understand the concept of Net Zero and analyze strategies to achieve net zero goal in high performance office buildings.

The four different sets of retrofit packages assumed various priorities when grouping the EEMs and this presented some interesting results. Suitability will always depend on the baseline building and its current energy demand and usage. measures that only focused on meeting the heating needs (such as the PV panels and Ground Source Heat pump) underperformed at reducing the PEC.

It may be that with the current level and price of EEMs available, finding a balance between the energy and cost benefits is one of the best options to carrying out energy retrofits and as such technologies become widespread in use, it is always possible to carry out further, albeit minor, retrofits in the future to fully meet the required standard. The absence of a harmonious definition and standardised methodology endorsed by the government and industry is currently one of the main obstacles to implementing the standard on a national scale, rather than the lack of technical and financial capabilities.

Recommending most effective design strategies for net zero energy building in warm and humid climate of India.

Net zero buildings mainly work on three parameters, passive and active strategies followed by renewable energy systems. The main principle of these buildings should follow passive strategies first to optimize energy consumption from active strategies. Residual energy demands are fulfilled by renewable energy systems.

3 Design Issues for Net Zero-Energy Buildings

Aelenei L, Aelenei D et al.

Ongoing research insights on best practices leading to NZEBs with close examination on chosen strategies

To bridge the gap of data availability on suitable strategies for making a building NZEB. The paper focuses on a combination of passive and active strategies and runs a feasibility test to see the most efficient outcomes

The outcome is in a form of a matrix which shows the different techniques that respond to heating, cooling, lighting and other equipments. The paper has brought in light through systematic analysis particular strategies from the wide range of techniques to reach a Net Zero Energy goal.

The paper gives a good insight on how through case studies and analysis of NZEB performance along with its challenges, a guideline can be formed to evaluate the best solutions and form the guidelines through a matrix. This method of study can be adapted for our research and done on commercial buildings in warm and humid climate.

4 Identification of key factors for uncertainty in the prediction of the thermal performance of an office building under climate change Wilde P. Tian W.

Research insight through a case study on the uncertainty of heating and cooling loads in an office building to cope with the upcoming climate changes in the years 2030, 2050 and 2080. The article uses two-dimensional Monte Carlo analysis and Energy Plus model of an office building to study the uncertainty in predictions of overheating and energy use in the mentioned time horizons.

Literature Review

To understand the different uncertainties led by climate change, heating, equipments and energy used across different time horizons for an office building.

-Uncertainty in heating energy should decrease overtime

-Uncertainty in cooling and overheating will increase through time

-The key factors identified for the study are as follows:

Future weather, office equipments, lighting and infiltration rate, envelop absorption values etc.

This research helps us to understand different variables and factors, and the various uncertainty associated that are important while retrofitting an office building such that it considers the thermal conditions and climate change in the upcoming years.

Title of Paper Factors Considered for Study Purpose of the Study Outcomes and Findings

5 A review of net zero energy buildings in hot and humid climate: Experience learned from 34 case studies buildings

Feng W., Zhang Q., Ji H., Wang R. et al

Through 34 NZEB cases around the world, analysis of key design strategies, technology choices and energy performance.

To evaluate NZEB performance and summarize best practices for high performance NZEBs. To find policies and information regarding net zero energy buildings in hot and humid climate.

Inference/Research Gap

6 Examining the Role of Building Envelop for Energy Efficiency in Office Buildings in India

Bano F., Arif

Kamal M.

7 The Role of the Building Envelope in Achieving Nearly-Zero Energy Buildings (nZEBs)

Stergiani Charisia

8 Transformation of an Office Building into a Nearly Zero Energy Building (nZEB):

Implications for Thermal and Visual Comfort and Energy Performance

Ilaria Ballarini, Giovanna De

Luca, Argun Paragamyan,

Energy conscious design approach helps designers and building owners to economically reduce building, while increasing comfort. The energy consumed depends on operation, use, type od building and climate, and envelop designing plays a big role to control same.

To ensure the sustainability of energy consumption even with the growing demand of office spaces. Through efficient envelop after evaluating the effects of

-Not all NZEB energy-efficient technologies are energy efficient

-Natural ventilation and other passive technologies can help reduce the cooling energy

-PV are the most common renewable energy technology

-Engaging occupants and effective building base load control is important

-Requirement of national policies and local level standards.

-The building is responsible for 26% of the energy consumption

-Vast potential of energy saving is possible through efficient design of building envelop design

-Recommended orientation according to sun and wind in northwest and south east

-Shape should be a rectangle with aspect 1:2 and width 15m for minimum heat transfer indoors.

The research does a detailed analysis on the case studies and concluded the different passive and active techniques that are suitable and efficient in hot and humid climate.

This concept can be done in the context chosen, as even the paper states, that developments and study still need to be carried out in other countries.

Model Building and Dynamic Simulation, Parametrical analysis with innovations in insulation, efficiency in openings and impact on shading devices,

The effect of various parameters on the energy demand of the building, such as insulation, openings and shading devices, was investigated and evaluated. T

The use of innovative insulation materials with low thermal conductivity, such as the VIP, establish a very promising constructive solution that can combine high energy performance and aesthetics.

Different techniques for efficient envelop design for office buildings. The different components like wall, roof and fenestrations are considered together, incorporating active and passive techniques.

Building Energy Refurbishment; Thermal Comfort; Visual Comfort; Energy Performance

Literature Review

The dynamic simulation analysis indicates that the increased thickness of the insulation layer consists a simple and very effective solution for decreasing the total annual energy demands of a building.

Furthermore, other simple constructive solution, such as the application of openings with improved

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.

The overall energy savings that result from retrofitting actions on existing buildings could be much more significant if the envelope retrofitting design strategies were optimised to enhance a sufficient daylight provision and visual comfort, while guaranteeing the same thermal comfort level.

It should be noted that insulation is generally advantageous in a winter-dominated site to increase the thermal comfort on a yearly basis.

Compared to a uninsulated configuration, the cold discomfort periods in the nZEB decrease much more than the warm discomfort periods increase. Likewise, the increase in the free-floating hours is higher than the increase in the space cooling hours.

Energy audit studies in buildings have shown large potential for energy savings in commercial office buildings.

The Star Rating Program for buildings would create a demand in the market for energy efficient buildings based on actual performance of the building

To apply for rating of office buildings, a standardized format is developed for collection of actual energy consumption: data required includes:

• building’s built up area,

• conditioned and non-conditioned area,

• type of building,

• hours of operation of the building in a day,

• climatic zone

• Information of the facility

The Building Technologies Office research is helping make buildings become smarter about the amount and timing of energy use and emit less carbon through the Gridinteractive Efficient Buildings (GEB) Initiative.

EFFICIENT CONNECTED SMART FLEXIBLE

Persistent Low Energy use Minimises Demand

On Grid Resources & Infrastructure.

Two way communication with flexible technologies, the grid and occupants

Analytics supported by sensors and controls cooptimise efficiency, flexibility and occupant preferences.

Two way communication with flexible technologies, the grid and occupants

Data Collection

Flexible loads and distributed generation/storage can be used to reduce, shift or modulate energy use.

The GEB Initiative works to remake buildings into a clean and flexible energy resources by combining energy efficiency and demand flexibility with smart technologies and communications

The GEB Initiative leads the fundamental research, development, demonstration and deployment of GEBs.

BUILDING ENVELOPE

• The separation between a building's interior and outside.

• The envelope protects the inside while also allowing for climate control.

• The term "building envelope" refers to your home's full ou ter building system.

OF PAPER TYPE METHOD IDENTIFIED OUTCOMES INFERENCE

1 Patterns To Daylight- People And Sustainability

Mixed Daylighting Design

Because solar heat gain can be beneficial or harmful, no pattern is established for daylighting dashboard colour ratings.

• A pleasant, productive, healthful, ecologically sensitive, and cost-effective design must have good daylighting design.

• Step Dimming is a foolproof methods wrt all the expectations made with this research.

2 Potential Benefits Of Cool Roofs On Commercial Buildings: Conserving Energy

Passive Cool Roofs- Solar Absorption, Heating energy. Mercury. Nitrogen oxides. Solar reflectance.

This study compares simulations of the building's cooling and heating energy needs with a cool roof to those with a conventional roof to quantify the impact of a cool roof on the building's conditioning energy consumption.

• The impact of installing a cool roof on energy consumption is well-matched to the climate.

• However, geographical variances in energy pricing and electrical emission parameters, as well as climate, can affect per-CRA figures of yearly energy cost savings and emission reduction.

Solar Passive Design And NZEB

Passive Operable windows, thermal mass, and thermal chimneys are common elements found in passive design.

• During the day, the thermal mass absorbs heat; however, high humidity reduces the cooling impact of the colder thermal mass.

• The efficacy of passive cooling in our location is also influenced by the interior design aspects of a home.

• MOST OPTIMAL: Thermal chimneys can be built in a narrow format (like a chimney) on the interior, with a readily heated black metal absorber behind a glass front that can achieve high temperatures while remaining insulated from the building.

• The chimney must end above the level of the roof.

SL NO. TITLE OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Net-Zero Building Designs In Hot And Humid Climates: A State-of-Art

Passive Basic rules, natural ventilation systems, cooling and dehumidification, insulation, and building materials are all included in the paper's framework.

• Humidity has been identified as the mo st significant issue in these places, maki ng it difficult to implement measures th at have been successful in other climat es.

• Cooling alone is insufficient to provide comfort for residents, yet it accounts fo r the majority of energy usage.

• Improved building envelope, HVAC, lighting system, and integration of passive components for heating and cooling were among the retrofit options.

Natural ventilation systems must be i nstalled in regions where the wind v elocity is strong enough. To achieve energy independence, several design ideas and tactics ar e required to ensure seasonal comf ort performance.

Double glazing with low-E coating and argon gas fill was selected to substitute glazing for windows, thus significantly reducing heat transfer through the building envelope

Net-Zero

Building Designs

In Hot And Humid Climates: A State-of-Art

Passive Basic rules, natural ventilation systems, cooling and dehumidification, insulation, and building materials are all included in the paper's framework.

• Humidity has been identified as the mo st significant issue in these places, maki ng it difficult to implement measures th at have been successful in other climat es.

• Cooling alone is insufficient to provide comfort for residents, yet it accounts fo r the majority of energy usage.

Natural ventilation systems must be i nstalled in regions where the wind v elocity is strong enough.

To achieve energy independence, several design ideas and tactics ar e required to ensure seasonal comf ort performance.

TITLE OF PAPER TYPE METHOD IDENTIFIED OUTCOMES INFERENCE

The Impact of an Ideal Dynamic Building Envelope on the Energy Performance of Low Energy Office Buildings

Mixed Dynamic systems; low energy office buildings; numerical simulation; responsive building components; ideal building skin; façade;

The investigation's findings revealed the benefits of a dynamic WWR setup over a static one. However, the reductions in energy usage were le ss than anticipated.

Even though the gains in energy demand were less than projected, the investigation's findings indicated the benefits of a dynamic WWR design over a static one.

Transformation of an Office Building into a Nearly Zero Energy Building (nZEB):

Implications for Thermal and Visual Comfort and Energy Performance

Passive Aim: To emphasize that energy retrofit efforts on the building envelope would result in considerable improvements in thermal performance, both in terms of energy savings (37% of yearly primary energy for heating) and thermal comfort.

Many studies have examined commonly used retrofit actions and found that a reduction in daylight availability has a negative impact on visual comfort; these actions primarily included

• window replacements,

• solar shading device installations,

• and the reduction of window carcasses due to the thickening of thermal insulation.

Overall energy savings from retrofitting actions on existing buildings may be significantly greater if envelope retrofitting design tactics were optimized to provide adequate daylight and visual comfort while maintaining the same degree of thermal comfort.

part

the

The eight various construction typologies are compared in terms of primary energy usage and carbon footprint across the life cycle of the structure. The transportation of building goods is also included in the inventory analysis throughout the assessment procedure.

The contribution of the materials to t he impact assessment study shows a large influence of the concrete m anufacturing process with over 80%, while the proportion of insulating m aterial ranges from 9% for PCM, 13% for stonewool, and up to 15% for ex truded polystyrene.

Data Collection

HVAC

• The technique of indoor and vehicle environmental comfort is known as HVAC (heating, ventilation, and air conditioning).

• Its purpose is to offer enough thermal comfort and indoor air quality. HVAC system design is a branch of mechanical engineering that is based on thermodynamics, fluid mechanics, and heat transfer concepts.

A Guide For Best Practices For Ground-source (Geothermal) Heat Pumps

TYPE METHOD IDENTIFIED OUTCOMES INFERENCE

• When passing across the perforated holes, part of the air, known as the ‘working (or secondary) air’, is diverted into the adjacent wet channels.

• Within the wet channels, the air travels in normal direction to the dry channel air, taking away the evaporated water from the saturated wet surface of the plate and receiving the sensible heat transferred across the plate.

Although significant progress has been achieved in developing the IEC technology, several inherent difficulties still remain with this subject, namely

• relatively lower cooling effectiveness

• smaller temperature reduction potential

• larger geometrical sizes; and higher dependency to the ambient condition.

Active

• Desiccant Systems- Closed, Commercial, Open, Liquid,

• A desiccant is a solid or liquid which dries air by attracting water molecules onto the desiccant surface. The dry air is then cooled by direct or indirect evaporation and sent to the air-conditioned space.

• For solid desiccants, no corrosive fluid will be involved in system operation. Liquid desiccants, on the other hand, are easy to pump to the desired locations.

• Trying to determine which model is most accurate is very difficult because of the sparsity of reliable experimental data and the uncertainty of internal mass diffusion parameters.

• A number of comparisons have been performed among many of these different computer models.

• Whenever the internal mass transfer is negligible, all of the models will yield excellent agreement with available experimental data.

Active • Ground-coupled systems, Ground water systems- Closed and Open Loop Systems, geothermal heat pumps.

• Understanding the process of heat exchange with the ground requires not only knowing the current heat transfer conditions, but also the heat extraction or rejection to the ground that has occurred in the past.

• A properly designed GHP system will not present any challenges for the experienced installer. The best designs will be simple and will make the installation easy.

• Pumping energy consumption in GHP systems can be excessive if proper care is not taken in the design..

Aside from the energy savings, which are difficult to generalize, there are significant carbon footprint savings that can be realized from GHP when displacing fossil fuels for heating.

Based on a TRNSYS model verified by a domestic NZEB, this study assessed the energy, comfort, and economic performance of commercially available HVAC solutions for a residential NZEB .statistics from the previous year's operations

• The GSHPs with the ERV and specialised dehumidification gave the biggest energy savings and comfort, but they were also the costliest.

• The option with the lowest initial cost that met the net zero energy target with good comfort was the ASHP with dedicated dehumidification and ventilation without recovery.

Active The yearly heating and cooling load of a building is compared to the annual energy consumption by the building's HVAC system in TSPR.

With tailored TSPR calculations, the HVAC System Performance method might be applied to any code or building energy standard.

The TSPR tool, which simplifies the application of the HVAC System Performance method, allows designers and engineers to quickly analyze how alternative system design choices affect the overall performance of the HVAC system.

6 Regenerative Design And Adaptive Reuse Of Existing Commercial Build ings For Net-zero Energy Use

Active Biomass Heating Systems

• Multiple design aspects were evaluated based on detailed energy modelling and simulations, including biomass heating systems.

By combusting biomass fuels, a biomass heating system was incorporated into the building's HVAC system, providing considerable cost-saving, environmental, and social advantages.

SL NO. TITLE OF PAPER TYPE METHOD IDENTIFIED OUTCOMES INFERENCE

Retrofit strategies to obtain a NZEB using low enthalpy geothermal energy systems

By comparing low enthalpy geothermal syst ems, four energy retrofit scenarios may be cr eated.

The difference between using two disti nct geothermal systems (i.e., ground so urce heat pump GSHP, ground-toair heat exchanger GAHX) and a more popular heating and cooling generat or like an airsource heat pump is analyzed from an energy and cost standpoint.

When geothermal energy (which is free a nd fairly consistent throughout the year) is used, energy savings may be considerab ly improved, mostly by installing a GSHP. Air source heat pumps, on the other hand , can fail in especially cold areas.

Integrated HVAC and DHW production systems for Zero Energy Buildings

Active

• Gas boiler

• Solid biomass-based system Solar assisted heat pump Condensing boiler-heat pump Zeolite based integrated system

• Overall, the compact HVAC emerges among reviewed production systems for addressing energy needs for space heating &cooling, DHW, ventilation & air handling in one packaged set-up with a ‘water’ and ‘air’ side.

• The overall energy behavior of this configuration should be monitored to prevent divergences from expected performance.

Multienergy systems allow you to overcome the drawbacks of stand-alone (monocarrier/monoconverter) energy systems by feeding them with a mix of different energy sources.

Case Study: Smart Building Energy Inefficiencies Detection Through Time Series Analysis And Unsupervised Machine Learning

Active Time Series Analysis And Unsupervised Machine Learning

This paper proposed a step-by-step technique for uncovering HVAC management improvement potential in highly efficient buildings using the Kmeans algorithm, an unsupervised machine learning algorithm.

• The findings indicate that utilising time series analysis and an unsupervised learning approach, it is possible to identify timeslots where HVAC usage may be reduced or eliminated.

• Our research demonstrates the possibility of saving up to 6% in energy, which energy managers should consider for future HVAC system configurations.

LIGHTING

• Lighting accounts for more than a quarter of total buildin g energy usage.

• To attain net zero goals, it is critical to optimise lighting en ergy usage.

• Lighting fixtures that are energy efficient are now widely availableThese must be used in tandem with daylighting.

• Daylighting controls and occupancy sensors might help t o minimize lighting energy use even more.

Main Street NetZero Energy Buildings: The Zero Energy method in concept and practice

TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Passive/ Mixed

Optimum shading in the southern façade. Consideration of solar geometry for consideration of adding/ removing interior partitions Overall simulation of daylight distribution for optimal positioning of interior programs

Using daylighting sensors for lighting intensity control (LED with linear control)

Glare

and visual discomfort can be

reduced

Working with the solar movements help reduce cooling requirements, and achieve sufficient daylight in the interior without any visual discomfort

Helps control over-use of mechanical lighting and optimizes daylighting

The study was based on the climatic conditions for Iran. Though being a continental with both hot and cold, the natural lighting or daylighting is strategies can efficiently adapted for retrofitting projects.

Passive Active/ Mixed

Lighting shelves can be used to bring daylight into the deeper parts of the building.

Side-lighting and Top-lighting, Skylights, Transparent roofs, Semi-transparent PV roofs

Daylighting hours according to ECBC: 40% to 60%.

100% daylighting

Side-lighting and Top-lighting are commonly used, others can be used for glare free vision

Through the strategy mentioned the daylighting hours should be maintained.

Artificial lighting sensor (lighting power density) LED fixtures, Task lights, Daylight sensor, Occupancy sensor, Sensor grids

9.50 LPD (80 l/wt.)- 5.0 LPD (100 l/wt.)

Depending on the building size

To attain lighting performance index of 20 kWh/m2/yr. with a LPD of 5.3

Automatic lighting control helps in energy optimization. Censors help in reducing the lighting performance index of the building

Passive Active Mixed

Orientation: east-west axis grants maximum daylight. No shading on northern facades allows indirect light to enter.

Southern façade with overhangs to cover lower vision glass.

Louvers allowing daylight penetration covering 100% office space.

Efficient use of 25-W, T-8 electrical lighting

Design average 0.63 W/ft2, supplying 30 foot candles at the workstation

Localised electric lighting through LED lamps that consumes 13 W.

Daylight dimming sensors, occupancy sensors, manual controls, photosensors

Proper orientation ensures good daylighting opportunities

Shading depending on the facades allows only indirect light to come in, thus reducing the chances of glare and discomfort.

The more space covered by daylight, less is the demand for electric light sources.

Using efficient light sources, allow less consumption of power an thus reduces the overall energy consumption.

Sensors help in automatically

Orientation though a very good strategy is not changeable in the existing building. Thus façade shading and glazing becomes important for optimum use of daylight.

Daylight or natural light covering the maximum space reduces energy needs and is first step towards efficiency Finally, efficient light sources are to be used wherever required.

Sensors help in optimising the power use according to need.

CHAPTER THREE: LIGHTING

PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Transformation of an Office Building into a Nearly Zero Energy Building (nZEB): Implications for thermal and visual comfort and energy performance

Ilaria Ballarini, Vincenzo Corrado, 2019

Active Passive

Lighting- LED luminaires, daylight depending dimmer Photovoltaic system: direct lighting North façade with no shading devices and South façade with shading to prevent direct light

15 kW luminaires and, 8.91 W-m2 LPD properties for the lighting can achieve an efficient system Increase daylight inside the building and create less demand

Efficient technical systems with low energy consumptions

Shading devices can be installed and the building facades modified for the following result.

The

Optimization of Visual Comfort and Energy

Consumption Induced by Natural Light Based on PSO

Yonggang Zhang et. al, 2018

Design and optimization of novel electrowetting-driven solar-indoor lighting system

Yonggang Zhang et. al, 2018

Optimizing window to wall ratio for conserving energy in office buildings for cooling dominant climate with or without daylight utilization

Altaf, Madeeha, 2019

Optimizing of an external perforated screen for improved daylighting and thermal performance of an office space

Cristian Lavin, Francesco Fiorito, 2017

Passive Mixed Curtains on south and east walls

IIoT-based smart controlling system, with cloud based services, smart gateways and automatic curtains with light sensors

Removes discomfort due to direct incident light.

Sensors collect data send periodically through gateways and function the automatic curtain. This provides visual comfort while being low-cost and easy to deploy.

This controls the interior light level and works according to demand. It can control the occupants visual comfort and also pair up with thermal comfort.

Passive/ Mixed E-Sil mechanism: Sunlight collection and transmittance through liquid prism that controls same using reflectance

The light transmitted through reflectance controls the lighting power, and the excess sunlight can be recovered. For e.g., 1m2 of solar collection can provide 2260h for 10m2 surface

Passive WWR ratio of 13 to 30% according to the orientation Optimum WWR can be used to achieve he threshold lighting for the interiors of an office building

This method has a higher installation cost and can be used for office building with lower heights. For tall structures this mechanism cannot be used for the lower levels.

This is feasible for any climate situation, with a cooling demand, and can be used depending on the orientation of the building to achieve optimum lighting.

Passive Perforated screen parallel to windows along the south-east and south-west facing windows

Five performance results show that the glare probability has been reduced and there is optimization of daylight energy use

This methodology is stringent in terms of form, and depending on the location of the windows and facades, performance will vary.

CHAPTER THREE: LIGHTING

SL NO. TITLE OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

An optical design analysis of a novel parabolic trough lighting and thermal system

Mixed

Innovative parabolic trough solar lighting and thermal system: two-axis solar tracking and collector.

The visible light is reflected by a cold mirror, re-concentrated using a secondstage Fresnel lens and transferred through plastic optical fiber to be used as natural interior lighting. The infrared rays are reflected and reaches as thermal system

Total solar energy efficiency- 39.4% with lighting efficiency of 16.3%. Despite the efficiency, warm and humid climate does not require thermal heating. 23.1% out of the 39.4% is responsible for the heating which makes it a better installment for heating than lighting.

McHugh

Skylights (5% roof area)

Passive Daylight adaptation design using data analysis from ray tracing. Geometry factors: Beam radiation and reflector, light shelves, exterior reflectors, overhang

Reduces the requirement of electrical energy.

Need to use Energy conservation measure case,

Corresponds with the robust properties like reflection, transmission and absorption. This will help precisely design the daylight geometry and use appropriate reflectors and materials

Passive South façade shading Balance daylight quality and brightness patterns.

Reduces glare and user discomfort

Creates increase demands of cooling loads. Total result in 5% reduction of energy need.

Allows to appropriately use the geometry to tools to achieve the optimum daylight, that reduces energy requirement without compromising cooling req.

A vey efficient technique in the warm and humid climate, that can be integrated and used for lighting and thermal comfort

American Solar Energy Society, 2010

Regenerative Design of Existing Building for NetZero

Ajla Aksamija, 2015

Passive Curtain wall system

Exterior horizontal sunshades with aerofoil-shaped blades

Controls direct exposure from sunlight and decreases glare, making the interior daylight ambient and comfortable

A good example for retrofitting projects where it can be easily used to control uncomfortable daylight situations

OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Automated

Passive Methodical zoning of occupancy spaces

Lighting design according to occupant needs

Including window glazing with high visual light transmittance for daylighting in the interior spaces

Lighting requirements can be controlled according to need

Good natural daylight can be attained and reduces the need for electrical lighting

These are integrated methods that help the lighting or visual conditions while also keeping in mind the heat gain and occupant comfort, and are holistic approaches

Maria Ferrara, 2017

Passive Louver systems on high WWR facades. South façade- horizontal louvers East façade- vertical louvers with slat tilt angle

Stops building from unnecessary solar gains causing glare and discomfort (both visually and thermally)

This mechanism is suitable for retrofitting building with high WWR and glass facades in a effective way.

Fransisco Fernandez Hernandez, 2017

Multi-objective optimization framework for designing office windows: Quality of view, daylight and energy efficiency

Peirman Pilechiha et al 2015

The influence of daylighting in building with parameters nZEB: application to the case study for an office in Tuscany Mediterranean area

Passive Optimization of window design: Ratio, glazing, orientation, reflectance, size, components and materials

Balance maximum energy efficiency through natural lighting and provide best optical visuals

Though it is an efficient strategy, few constraints are set in case of an existing building and climate 17

Passive Active

Cristina Carletti 2017

Windows with double glazing and appropriate visible light transmittance

Outdoor white diffusing drapes

Reflective factor of interior surfaces

Fluorescent tubes with power consumption of 58W Lamps installed properly calculated by flux method

Allows daylight inside the building reducing artificial lighting demands Reduces the direct sunlight from entering

Energy efficient alternative for artificial lighting

Suitable for climate which require more cooling and helps in reducing visual discomfort

Reduces the amount of energy used by the building

Case study: India’s first Net-Zero Energy BuildingIndira Paryavaran Bhavan

TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Passive Mixed

Skylights and light wells

TDD- tubular daylight device

Soda Pop Bottle solar light

Clerestory windows/ Sawtooth roof Light reflectors and shelves

Louver systems and facade

Passive Zenithal Light pipe

Luminescent Solar Concentrators

Active daylight system with single-axis tracking system:

linear Fresnel, parabolic trough

Active daylighting system with dual-axis sun-tracking system:

Fresnel lens, parabolic dish, heliostat field, himawari system, core sunlight system

View ad Illumination from overhead

Plastic bottle filled with water used for reflecting light

Different window systems to allow indirect light to penetrate in without causing glare

A flexible polymer light guides act as collectors and guide the daylight to the building

Solar concentrators are highly efficient light couplers for sufficient sunlight for indoor illumination.

The light can be used with efficient glazing material

Most inexpensive way, but inefficient for large projects

Good luminous efficacy and lightto-light efficiency

Requires precise sun-tracking system and high optical efficiency for daylight collection and distribution

Active Passive

Lux level sensors

Installed integrated photovoltaic BIPV Courtyard with skylight

Optimize operation of artificial lighting. The total lighting power density is LPD= 5W/m2, which is more efficient than as stated in ECBC

75% of the building floor is provided with adequate daylight

Efficient active sources that require less energy and yield the maximum lighting

Rati Khandelwal, 2020

A simplified method to estimate energy savings of artificial lighting use from daylighting

Passive Active Mixed

Moncef Krarti, 2014

Interior movable shades

Recessed fluorescent troffers: standard commercial installments according to ASHRAE

Daylight sensor

Internal control and reduce glare

Maximum efficiency according to standard

Used for dimming and daylight control to reduce unnecessary use of artificial light

Efficient strategy for low structures and requires careful planning for high stories

Shading according to the report is a difficult attribute of design and requires personal preference. Appropriate lighting density achieved

A single sensor instalment can help achieve a huge difference in energy use

Nneka Obianuju Onubogu, 2021

EFFICIENT APPLIANCES

• Appliances have become an inextricable part of modern life. It's no surprise, therefore, that the amount of energy used by typical equipment in houses is continually increasing.

• Appliance efficiency may go a long way toward conserving energy in buildings. It depends on the appliances that people purchase as well as how they are utilised.

• This section provides information on the many options accessible to users, as well as the criteria for picking the appropriate appliances and best practises for their use.

SL NO. TITLE OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

The operational performance of "net zero energy building":

A study in Hot and Humid

Mixed Solar PV Cells, Energy Metering, Simulation Models

During the design process, a solar PV syste m with a capacity 20% higher than the sim ulated energy consumption was selected.

This technology might hypothetically meet the requirement of zero energy use.

The real power usage was 30.9 perc ent more than the simulation model projected.

Case Study: Smart Building

This paper proposed a step-by-step technique for uncovering HVAC management improvement potential in highly efficient buildings using the Kmeans algorithm, an unsupervised machine learning algorithm.

• The findings indicate that utilising time series analysis and an unsupervised learning approach, it is possible to identify timeslots where HVAC usage may be reduced or eliminated.

• Our research demonstrates the possibility of saving up to 6% in energy, which energy managers should consider for future HVAC system configurations.

Energy saving upto 75% for some of the products. The electrical standards help in less energy use

Using STAR labelled decreases almost have of the energy used especially in offices

SL NO. TITLE OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Integrated HVAC and DHW production systems for Zero Energy Buildings

Active

• Gas boiler

• Solid biomass-based system

• Solar assisted heat pump

• Condensing boiler-heat pump

• Zeolite based integrated system

• Overall, the compact HVAC emerges among reviewed production systems for addressing energy needs for space heating & cooling, DHW, ventilation & air handling in one packaged set-up with a ‘water’ and ‘air’ side.

• The overall energy behavior of this configuration should be monitored to prevent divergences from expected performance.

Multienergy systems allow you to overcom e the drawbacks of standalone (mono-carrier/monoconverter) energy systems by feeding them with a mix of different energy so urces.

6 Regenerative design and adaptive reuse of existing commercial buildings for netzero energy use

Active The yearly heating and cooling load of a building is compared to the annual energy consumption by the building's HVAC system in TSPR.

With tailored TSPR calculations, the HVAC System Performance method might be applied to any code or building energy standard.

The TSPR tool, which simplifies the application of the HVAC System Performance method, allows designers and engineers to quickly analyze how alternative system design choices affect the overall performance of the HVAC system.

Mixed PVs- High efficiency Commercial photovoltaics with high efficiency were evaluated for installation on rooftops.

There are several advantages to using this gridconnected PV system in a business refi t project.

The devices are straightforward to inst all and maintain due to their very basi c setup.

RENEWABLE ENERGY

• Renewable energy systems are the last step towards achieving zero-energy targets and are the indicator of a building’s success towards reaching nZEB..

• Renewable energy systems must step in to balance remaining energy demand once all viable efforts to minimize energy demand have been implemented.

• Renewable energy systems can be included into the building during the early design phase or added later as retrofits. While solar energy is available everywhere, other renewable energy sources are very site dependent.

CHAPTER FIVE: RENEWABLE ENERGY RESOURCE

TITLE OF PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Use of PV panels to produce renewable energy. Energy is available in surplus throughout year.

Here solar energy is used as a heating source, generally for heating domestic water or for cooling in chillers Installed at a higher level to use the wind speed to generate electricity

Sunlight is captured in the area of exposure and electricity is generated. The system should be built in a suitable location where sun exposure is good

Wind power is converted into electricity

Efficient and commonly used method with good results in the selected climate

These solar mechanism however depend on temperature and weather, along with their orientation Not very common in NZEB building, and is not used in low rise

The roof mounted PV systems are more efficient for its exposure. And the boundary systems have a chance being shaded

Off-site renewable energy grids

High energy demands can be met by these off-site grids

They have limited application For commercial offices they are not very relevant until excess energy is required

Zero Energy Buildings: A critical look at the definition

Active Production and use of natural gas

Can be used for space and water heating

Is a continuous source of energy, however requires big investment for installment, and is not required for space heating

Advancing Net-Zero Energy Commercial Buildings

Crystalline PV modules with 0.0 tilt

Mixed NZEB:A- sources on footprint

NZEB:B- sources on site

NZEB:C- off-site sources

NZEB:D- purchase off-site sources

Best available output for commercial system

Incorporating proper technologies help in generating a cost-effective solution for energy efficiency.

These classifications are of NZEB based on their renewable energy source

Because of the high level of success can be used efficiently

For an commercial/ office building, the renewable resources available on the footprint is best

CHAPTER FIVE: RENEWABLE ENERGY RESOURCE

PAPER TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Power

Urban

Power

Tidal

One of the cleanest sources and ensures continuous supply. However can be used in big return projects

Potential/ kinetic energy of water is converted to energy. Largest renewable source

Generated through a complex mechanism, the wind energy is used to move the turbines and produce energy

Most abundant permanent energy resource and is available for both direct an in-direct solar radiation

Generated from heat stored in the earth, but there is small resource opportunity

On-grid are the resources that are integrated within the project and production and supply takes place within the site

The energy that is delivered to the site from an outside production grid source

According to area available for installment, the orientation and roof type, the efficiency of the installments will vary. In case space is a restriction, measures can be taken to use the best materials

Some systems have very high investment initiative to be feasible for a commercial project. Few techniques like solar power or hydro power, are some of the efficient ones

Though being a clean source is not efficient for office retrofit

Is efficient enough and largely used and can be used with the availability of water source

Can be incorporated only in tall structures where the wind pressure requirement is met

Commonly used and easily accessible, the most efficient technique for warm and humid Scarce changes of availability

For a commercial retrofitting project, both scenarios are suitable depending on the amount of energy required. On-grid can be used for low, while off-grid for high energy requirements

The installment of such a model reduces the monthly electricity required and reflects on the financial benefit in their life cycle assessment.

CHAPTER FIVE: RENEWABLE ENERGY RESOURCE

TYPOLOGY METHOD IDENTIFIED OUTCOMES INFERENCE

Activity

Solar thermal as vacuumed pipes for domestic hot water Electricity through solar panels Hybrid system: combination of solar thermal and solar electricity for electricity and heating water

Active Hydro-power Wind power Solar energy

Decrease in energy costs as they are being produced on-site, also resulting in CO2 emission reduction.

Efficient inclusions for a commercial building that can help in attaining zero energy demand

Geothermal energy

Active Thermal and photovoltaic panels are used in the West façade

Potential/ kinetic energy of water is converted to energy. Largest renewable source

Generated through a complex mechanism, the wind energy is used to move the turbines and produce energy

Most abundant permanent energy resource and is available for both direct an in-direct solar radiation

Generated from heat stored in the earth, but there is small resource opportunity

Redesign the surface incorporating solar design to make use of the incident sunlight and generate electricity

Is efficient enough and largely used and can be used with the availability of water source Can be incorporated only in tall structures where the wind pressure requirement is met

Commonly used and easily accessible, the most efficient technique for warm and humid Scarce changes of availability

This acts as a integrated strategy as it solves both façade shading as well as acts as renewable energy source

Wind turbine Integrated to Tall Buildings

Active Wind turbines : On-grid source

Off- grid source

Retrofitting wind turn=bines on building/ creating stand-alone turbines

Wind turbine energy from the farms, a source of clean economical clean power

Minimum height required 1,4 above the roof only in tall structures. This method is not effective for low rise structures

BUILDING ENVELOP COMFORT/ HVAC LIGHTING DESIGN EFFICIENT EQUIPMENT RENEWABLE RESOURCE

ACTIVE DYNAMIC FACADE BIOMASS HEATING

LIFE CYCLE ASSESSMENTFACADES SENSOR BASED COOLING SYSTEM

FORCED VEGETATION

LED FIXTURE

PVS- HIGH EFFICIENCY SOLAR ENERGY

WIND ENERGY

TASK LIGHTING UNSUPERVISED MACHINE

LEARNING

FLOUROSCENT LAMPS ENERGY METERING

BIOMASS

HYDRO POWER

GEOTHERMAL ENERGY DEHUMIDIFICATION

LUX LEVEL SENSOR SIMULATION MODELS

PHOTOVOLTAIC BIPV

OCEAN TIDAL ENERGY

OFFSITE RENEWABLE ENERGY

PASSIVE OVERHANGS DIRECT EVAPORATIVE COOLING

COOL ROOFS INDIRECT EVAPORATIVE COOLING

FAÇADE DESIGN SOLAR ASSISTED HEAT PUMP

SHADING DEVICES

CONDENSING BOILER-HEAT

PUMP

MIXED MODE

SOLAR RADIATION: ORIENTATION GROUND-COUPLED SYSTEMS

FENESTRATIONS

DOUBLE GLAZING GEOTHERMAL HEATING GEOMETRY & INT. DESIGN

PASSIVE DEHUMIDIFICATION

BUILDING MATERIAL TECH TIME SERIES ANALYSIS

SIMULATION DATA

GLAZING & MATERIAL

DAYLIGHT SENSOR

TSPR ANALYSIS

SMART GLAZING DESSICANT SYSTEMS OCCUPANT SENSOR SPACE HEATING

NZEB: A- FOOTPRINT

NZEB: B- BUILDING SURROUNDING

SMART EXT FENESTRATIONS

SENSOR GRIDS SPACE COOLING

SUNLIGHT TRACKING

SUNLIGHT REFLECTOR

NZEB C: OFFSITE

NZEB D: OFFSITE

BUILDING ENVELOPE HVAC

Building envelop plays an integrated role in controlling the thermal comfort inside the building. It also helps in daylight control, ventilation and heating/cooling. Common passive methods depend on the design elements while new technologies are giving rise to smart fenestrations and dynamic facades. These techniques can be very efficiently incorporated in commercial existing building and can bring about a holistic change for the building. These elements help in controlling the energy, and smart technology controls the energy required, thus helping in achieving Net Zero Energy

For future work, we propose an implementation of a real-time collection of the number of users in the building and measuring the inside temperature, as this is important to understand the relationship between the indoor temperature and the changes in HVAC consumption.

LIGHTING

For lighting design a net zero building should first target reducing for artificial lighting, especially in the daytime. This is seen in cases of properly daylit interiors using various fenestrations and openings.

The next step should be using efficient lighting with less energy consumption and sensors to control them. This finally helps in optimizing the energy use whenever necessary

RENEWABLERESOURCES

Conclusions

EFFICIENTEQUIPMENTS

The most important part of energy requirement in offices are the equipments. They not only take in electricity, but also increase the cooling load by heat generation.

An efficient guideline for the equipments show exactly the specification that can be used to avoid excess energy utilization

Renewable resources are found in many forms, like solar, wind, geothermal etc. However while designing the investment and life cycle analysis helps chose the most feasible and efficient. Solar energy is very commonly used as energy and thermal sources, and is one of the most efficient methods.

Renewable resources become the ultimate factor that helps achieve NZEB by providing the energy required by the building

1. Ecofys. Towards nearly zero-energy buildings. Definition of common principles under the EPBD. Final report for European Commission; February 2013.

10. European Parliament, Council of the European Union. Directive 2010/31/EU of 19 May 2010 on the Energy Performance of Buildings (Recast). Off. J. Eur. Union 2010, 18, 2010.

2. 2. Technical Chamber of Greece. Introduction on Energy Field. Educational material for energy consultants; June 2011

3. 3. Institutions and Author. Study on VIP components and Panels for Service Life Prediction of VIP in Building Applications (Subtask A). HiPTI IEA/ECBCS Annex 39; September 2005

4. 4. Technical Chamber of Greece. Hellenic Regulation on the Energy Performance in the Building Sector. TOTEE 20701-1/2010; April 2012

5. The Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010 on the energy performance of buildings

6. Official Journal of the European Union. AYOUB, J., Factsheet Towards Net Zero Energy Solar Buildings, Task40/Annex 52. SARTORI, I., NAPOLITANO, A. and VOSS, K., 2012,

7. “Net zero energy buildings: A consistent definition framework”, Journal Energy and Buildings. AELENEI, L., LOLLINI, R., GONÇALVES, H., AELENEI, D.,NOGUCHI, M., DONN, M., GARDE, F., 2011,

8. “Passive cooling approaches in net-zero energy solar buildings: lessons learned from demonstration buildings”, CISBAT2011.

9. Department for Communities and Local Government, Sustainable New Homes – The Road to Zero Carbon: Consultation on the Code for Sustainable Homes and the Energy Efficiency standard for Zero Carbon Homes, London: Department for Communities and Local, 2009.

11. Hee, W.J.; Alghoul, M.A.; Bakhtyar, B.; Elayeb, O.; Shameri, M.A.; Alrubaih, M.S.; Sopian, K. The role of window glazing on daylighting and energy savings in buildings. Renew. Sustain. Energy Rev. 2015, 42, 323–343. [CrossRef]

12. Reinhart, C.F. Effects of Interior Design on the Daylight Availability in Open Plan Offices. In Proceedings of the ACEEE Summer Study of the American Commission for an Energy Efficient Environment, Pacific Grove, CA, USA, 18–23 August 2002.

13. Mainini, A.G.; Bonatoa, D.; Polia, T.; Speroni, A. Lean strategies for window retrofit of Italian office buildings: Impact on energy use, thermal and visual comfort. Energy Procedia 2015, 70, 719–728. [CrossRef]

14. Dussault, J.; Gosselin, L. Office buildings with electrochromic windows: A sensitivity analysis of design parameters on energy performance, and thermal and visual comfort. Energy Build. 2017, 153, 50–62. [CrossRef]

15. Ajaji, Y.; André, P. Thermal comfort and visual comfort in an office building equipped with smart electrochromic glazing: An experimental study. Energy Procedia 2015, 78, 2464–2469. [CrossRef]

16. Hernández, F.F.; López, J.M.C.; Suárez, J.M.P.; Muriano, M.C.G.; Rueda, S.C. Effects of louvers shading devices on visual comfort and energy demand of an office building. A case study. Energy Procedia 2017, 140, 207–216. [CrossRef]

Thank you ☺