Supporting Building Energy Efficiency and Environment Rating (BEEER) System through Large-Scale Implementation of Appliances MEPS and EE Labelling Program in Bangladesh Training on passive design strategies PwC India | Clean Energy December 2022 Contents of the training program 1. Basics of Building Simulation & Analysis 2. Climate Study 1. Climate Classification for Bangladesh 2. Weather data study – 1. EPW file components 2. Wind analysis 3. Solar analysis 4. Psychrometric chart analysis 3. Introduction to fundamentals of building physics 1. Building form and orientation 2. Window to wall area ratio 3. Shading devices 4. Selection of opaque and translucent building materials 5. Effective daylighting 6. Effective ventilation 1. Basics of Building Simulation & Analysis Basics of Building Simulation & Analysis Definition Building energy simulation utilizes a physics-based simulation engine used for the prediction and analysis of building energy use by solving heat transfer equations for dynamically varying weather conditions. It helps to predict building energy consumption, CO2 emissions, peak demands, energy cost and renewable energy production which otherwise are difficult to calculate manually. Applications Applications covered in the training Optimization of Optimization of Solar Shading Zoning and Space Impact Analysis of Optimization of Renewable Daylight and Cooling Energy Analysis Massing materials thermal comfort energy integration artificial lighting Consumptions Compliance for Development of a NetZero Optimization of Compliance at Urban energy use HVAC sizing and Optimization of Green Building Digital Twin of orientation, Facility Level forecasting load optimization visual comfort Certifications Existing Building massing and FAR Available Tools – Commercial and Freeware Commercial: IES, Design builder, SketchUP+Sefaira, Rhino-grasshopper, ecoSIM, etc Freeware: Equest, Openstudio, energy plus, etc 4 2. Climate Study Climate Classification for Bangladesh The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. Climate classi�cation of Bangladesh based on BSh köppen-geiger system: 1. BSh- Arid+ Steppe + Hot arid Am 2. Am – Equatorial + monsoonal Aw 3. Aw – Equatorial + desert 6 Weather data study: EPW file components • Dry bulb temperature refers basically to the ambient air • Direct and diffused radiation: Direct radiation is temperature. It is called "Dry Bulb" because the air intercepted unimpeded in a direct line from the temperature is indicated by a thermometer not affected sun. Diffuse radiation is scattered by atmospheric by the moisture of the air. constituents, such as clouds and dust. • Dew point temperature the dew point is the temperature • Direct and diffused illumination Diffuse light the air needs to be cooled to (at constant pressure) in arises from the scattering of light by molecules or order to achieve a relative humidity (RH) of 100% larger particles in the atmosphere and comes from many directions simultaneously; direct light arrives • Relative humidity is a percentage that represents the in a straight line from the sun without being amount of water vapor in the air at a given temperature scattered compared to the max possible water vapor amount at that same temperature • Total sky cover Total cloud cover is the fraction of the sky covered by all the visible clouds. • Barometric pressure is the pressure within the atmosphere of Earth. • Wind speed and direction is a • Ground temperature fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Link to weather files: https://www.ladybug.tools/epwmap/ 7 Weather data study: Dhaka Temperatures:>30 ° C Dry Bulb Temperatures Effect of temperatures and humidity on thermal comfort: Humidity:> 70% Relative Humidity 8 Weather data study : Wind Wind Rose DBT Rose RH Rose Wind rose for 8760 values on the DBT values corresponding to the RH values corresponding to the wind chart wind values values 9 Weather data study : Solar data Total radiation Solar radiation Solar radiation plays a vital role in buildings. The building design should utilize solar radiation to cater to the lighting and heating requirement of the occupants to the maximum possible extent in the daytime from the radiation to provide comfort depending upon the climatic condition of the region. Sun path with corresponding DBT Sun path with corresponding DBT >30 10 Psychrometric Analysis Psychrometric chart guide Thermal comfort on psychrometric chart The psychrometric processes of air include physical and thermodynamic properties such as dry bulb temperature, wet bulb temperature, humidity, enthalpy, and air density. 11 2. Introduction to fundamentals of building physics Building Form and Orientation N-S orientation Cooling consumption: 396 MWh Avoid E-W orientation Recommended N-S or S-N orientation E-W orientation S. Direction Radiation Wall area( m2) Radiation Intensity No (MWh) (MWh /m2) 1 North 375.2 861 0.44 2 South 992.3 861 1.15 Cooling consumption: 3 East 286.6 300 0.96 402 MWh 0.86 4 West 257.9 300 13 Window to Wall Area Ratio Considered a sample room of 3 x 4m with brick wall and single glazed unit located in Dhaka. WWR 90% 70% 50% 40% 30% EPI 301 296 284 276 264 % 0% 2% 6% 8% 12% savings Reduced window to wall area ratio reduces the solar heat intake and therefore reduces the EPI. Low WWR is preferred on east, west and south directions. 14 Passive Design strategy: Shading Devices Shade No shade Vertical Fins Horizontal Box Type EPI 264 255 248 241 227 % 0% 3% 6% 9% 14% savings Installation of shading devices reduces the heat intake from the glazing’s surface and therefore reduce the EPI. The horizontal shades are preferred for North and South directions, whereas vertical shades are preferred on east and west directions. 15 Passive Design strategy: Shading Devices 16 https://www.beepindia.org/ Passive Design strategy: Selection of Materials Brick + Brick + AAC + AAC + Material Brick insulation insulation AAC insulation insulation R-15 R-30 R-15 R-30 EPI 264.8 240.74 239.58 248.61 240.27 239.35 % savings 0% 9% 10% 6% 9% 10% 17 Passive Design strategy: Selection of Window Materials • As with opaque envelope components, U-factors measure thermal conductivity through the window components. • SHGC is the ratio of solar (radiant) heat gain that passes through the fenestration to the total incident solar radiation that falls on it. SHGC is a dimensionless number between 0 and 1. • VLT is the ratio of visible light that passes through a glazing unit to the total visible light incident on it. Clear Blue Grey Clear- Low-e Shade Type 6mm 6mm 6mm DGU DGU U-value 5.7 5.7 5.7 2.7 1.68 SHGC 0.8 0.57 0.55 0.69 0.42 VLT 0.8 0.57 0.43 0.78 0.63 EPI 264.81 259.25 258.33 261.8 244 % savings 0% 2% 2% 1% 8% 18 https://www.beepindia.org/ Passive Design strategy: Effective Daylighting Higher window Shallow floor plate Light shelf • Higher windows provides deeper daylight • Shallow floor • Lighter colors on interior surfaces reflect light penetration plates, allow better. • Generally, daylight penetration depth is greater day light • Helps in daylight distribution and reducing between 6m to 8m from the fenestration penetration glare. 19 Passive Design strategy: Effective Daylighting Key definitions Recommended illuminance values for different spaces  Lux: The amount of light that is cast on a surface is called illuminance, which is measured in lux. Area Illuminance (lux) This can be thought of as light intensity within a Offices specific area. Filing, copying, etc. 300  Lumens: The total output of visible light from a Writing, typing, reading 500 light source is measured in lumens. Typically, the more lumens a light fixture provides, more the Technical drawing 750 brighter it is. Conference and meeting 500  One lux is equal to one lumen per square meter Reception 300 (lux = lumens/m2). Archives 200 20 Passive Design strategy: Effective Daylighting Daylight metrics Design parameters that effect daylight Static daylight metrics Dynamic daylight metrics Building Surface Analysis grid geometry Materials • Daylight Factor • Daylight autonomy • Point-in-time • Continuous daylight autonomy • Useful daylight illuminance Window Wall Shading Sky • Daylight saturation ratio devices • Spatial daylight autonomy Orientation 21 Passive Design strategy: Effective Daylighting 90% 70% 50% 40% 30% 30% + Overhang Useful daylight illuminance improves with lower WWR and shading 22 Passive Design strategy: Effective Ventilation Wind driven natural ventilation Buoyancy driven natural ventilation 23 Thank You © 2022 PwC. All rights reserved. Not for further distribution without the permission of PwC. “PwC� refers to the network of member firms of PricewaterhouseCoopers International Limited (PwCIL), or, as the context requires, individual member firms of the PwC network. Each member firm is a separate legal entity and does not act as agent of PwCIL or any other member firm. PwCIL does not provide any services to clients. PwCIL is not responsible or liable for the acts or omissions of any of its member firms nor can it control the exercise of their professional judgment or bind them in any way. No member firm is responsible or liable for the acts or omissions of any other member firm nor can it control the exercise of another member firm’s professional judgment or bind another member firm or PwCIL in any way. PwC Psychrometric Analysis Acceptable range of operative temperature and humidity for air- Acceptable operative temperature ranges for naturally conditioned spaces conditioned spaces PwC 25