Fairconditioning Student Certificate Workshop Module V APPLICATION OF SIMULATION IN BUILDING ENERGY EFFICIENCY AND SUSTAINABLE COOLING

OVERVIEW What is thermal Comfort? Why worry about thermal comfort? Human thermal comfort. Factors affecting human thermal comfort.

INTRODUCTION OF BUILDING MODELLING & SIMULATION SOFTWARES Simulation: "A computer simulation is a simulation (imitation of real world situation), run on a single computer, or a network of computers, to reproduce behavior of a system. The simulation uses an abstract model (a computer model, or a computational model) to simulate the system." Source: (Wikipedia)

BUILDING SIMULATIONS ARE REQUIRED TO ANALYZE The cumulative building behavior as a result of the building design, components and systems can be deciphered. Simulations enable evaluation of the impact of building design decisions (architectural + services) on various aspects like lighting levels, energy consumption, wind movements, comfort etc. and anticipate real world scenario. This helps make valuable decisions at the design stage to facilitate choice of materials and systems and incorporate the same at implementation stage to achieve energy efficiency

APPLICATION OF SIMULATION SOFTWARE SIMULATION SOFTWARES To complement architectural and system design decisions To check Compliance to Statutory Standards Analysis of performance in Comparison to given Base case Example: Daylight analysis, Solar Insolation Ventilation Analysis Thermal Comfort HVAC system type Validation of Orientation etc Example: ECBC Compliance Environmental Clearance requirement (Wind and Daylight analysis for basements) Example: Whole Building Performance Comparison with ASHRAE Appendix G, NBC (as per LEED requirement) ECBC Compliance for GRIHA GRIHA EPI benchmark

BRIEF HISTORY OF BUILDING SIMULATION

BRIEF HISTORY OF BUILDING SIMULATION

TYPES OF SOFTWARES

AUTODESK ECOTECT Allows the user to play with design ideas at the conceptual level. Integrates lighting, energy and acoustic analysis. Used extensively for lighting analysis.

DIALUX A light planning program for calculation and visualization of indoor and outdoor lighting systems

DOE2 AND VIZ DOE Visual DOE 4.0 is a powerful, yet easy-to-use "front end" to DOE2.1E. It covers all major building systems including lighting, day lighting, HVAC, water heating, and the building envelope. Hourly results are available for detailed analysis

e - QUEST eQUEST is a freeware sophisticated, yet easy to use building energy use analysis tool which provides professional-level results with an affordable level of effort. This is accomplished by combining a building creation wizard, an energy efficiency measure (EEM) wizard and a graphical results display module with an enhanced DOE-2-derived building energy use simulation program.

ENERGY + AND DESIGN BUILDER Energy Plus includes innovative simulation capabilities including time steps of less than an hour. It can be used for simulations of many common HVAC types, naturally ventilated buildings, buildings with day lighting control, double facades, advanced solar shading strategies etc

HOW THE SOFTWARE WORKS? DATA INPUT COMPUTATION OUTPUT

DATA INPUT DETAILED MODE SIMPLE MODE SITE CONTEXT Location/ Climate Basic Software environment (preferences) such as units, project surrounds etc GEOMERTY MODELING Architectural 3d form details (Fenestration, Shading) Orientations Surrounding physical conditions BUILDING PARAMETERS Building envelope Artificial lighting density Occupant density Equipment density HVAC basics SCHEDULES All building parameters Door Window operations MECHANICAL SYSTEM Detailing Based on: System Design Standards of ASHRAE, ECBC, Green Building Rating System Requirements There are two modes of data input depending on the kind of output required. The simple mode is generally carried out with certain assumptions and is mainly worked out to understand the trends of a certain parameters such as energy consumption, thermal comfort or any other. The detailed mode is chosen for a more accurate prediction of the behavior of a given design and to do modifications in the design detail to suit a requirement. ARTIFICIAL LIGHTING Detailed

EXPECTED OUTPUT DATA C Clarity is required as to what the software user should expect as an output. Energy Consumption: Zone wise energy Consumption System wise energy consumption Fuel-type wise energy consumption Energy Performance Index Comfort hours System Sizing System Efficiency Quantification of Savings through Energy Conservation measures and technologies. Fresh air quantities Heat load quantities Artificial Lighting levels CFD analysis Solar Analysis Daylight Analysis Solar Radiation Intensities (Daily, Monthly, Yearly) Shadow patterns (Daily, Monthly, Yearly) The trainer should explain that, it is imperative that Objective of a simulation be clear even before a simulation is conducted. A plan or a programme needs to be in place for the method/ sequence of simulation to be conducted, so that the objective of the simulation be achieved at the end of it.

RESULT INTERPRETATIONS Example: Interpretation of result plays a key role in making design decision based on the simulation. CHECK POINTS Thermal comfort results of a zone => check for set point temperatures, Schedules, Equipment loads, leakages, door window opening schedule etc. Equipment capacity => Validate through CFMs of zones, set point temperatures. The trainer should bring to the notice of the students, that the various results act as check points from which various interpretation of designs in terms of the system type and sizing requirement, material use type, orientations, equipment parameters, set point temperatures etc. The Whole Building Performance method is used as a data for a comparative analysis between a the design of a set base case and the proposed design. COMPARISION Making design decisions by comparison of results by using of different systems/materials etc, and/ or it combinations.

The output quality depends on input data quality GARBAGE IN ARBAGE OUT The output quality depends on input data quality The more accurate the input data the more accurate the output Some of the most common garbage that goes in as as follows: Assumed / Inaccurate Schedules, Settings in Set-point Managers in the HVAC loops Error in Modeling, both building geometry and manual HVAC system loop setting. Wrong Interpretation of Base Case Requirements. Inability to translate the system design in the software. etc

LEVELS OF SIMULATION ANALYSIS Simulations can be carried out based on the accuracy of the result required. Simple mode can be adopted for : For a quick understanding of trends and comparisons. Help to make quick Preliminary Architectural Design Decisions. Detailed mode can be adopted for : Accurate results which are close to real conditions. Detailed Design modifications based on the results. Eg: Window louver design, Comfort Hours Calculations etc. Mostly required for proof of Compliance

SIMPLE MODE Case Example: Resbuild Tentative input data can be used. Calculated assumptions and guesses are allowed. Accuracy of result is questionable, but a basic trend can be understood. Case Example: Resbuild Resbuild is a simple toolkit to predict the expected energy demand of a residential building. Energy saving potential of the said building in comparison with a base case. No Modeling is required. Input data involves basic project details including Building and Facade areas, Orientation, Occupancy per unit, Building level LPDs of Common and Living spaces, type of Cooling/ Heating equipment's used that can be chosen from a drop down menu.

PROJECT DETAILS AREA DETAILS

BUILDING ENVELOPE DETAILS LIGHTING DETAILS

SPACE HEATING/ COOLING SYSTEM DETAILS HOT WATER SYSTEM DETAILS

RESULT This software is purely designed for energy simulation of residential buildings. The result is in the form monthly energy consumption values for Lighting, Cooling, Heating, Hot Water, Internal Fans and Appliances in form of graphs and tables. Also shows the energy consumption in comparison with a reference base building. Results such as system efficiency, zone wise energy consumption, are not known. This tool can only be used to only provide a general overview of the project energy performance for a design condition.

DETAILED MODE Case Example: Design Builder Input Data to be as accurate and as detailed as possible The level of detailing will depend upon the level of detailed output and accuracy required. Assumptions need to kept to minimum. Case Example: Design Builder Design Builder is a graphical user interface with Energy Plus energy simulation engine. Provide interface for detailed modeling of each zone Respective schedules for each zone can be set in terms of its Occupancy, Lighting, HVAC, Heat Equipment etc. Option of Simple and Detail HVAC modeling available. Detailed and Accurate input data required. In Detailed mode there are limitation to assemble certain HVAC system.

Detailed Input Parameters Detailed Modeling Detailed Input Parameters

Add Fins/ Shading devices after day light simulations conducted for the same, to curtail unwanted solar radiation

Zone Activity input data (Occupancy details, Temperature set Points, lux levels required, Fresh air requirement, Equipment density.)

Envelope material description with respective Thermal Properties

Window/ Door Opening Schedule

Occupancy Schedules

Lighting Power Densities for each zones

HVAC Detail assembly for each zones

Result output (Annual/ Monthly/Daily) of Energy, Comfort, System Sizing, Site Conditions

UNDERSTAND REQUIREMENT OF THE PROJECT SUMMARY Enable to make Architectural + Services design Decisions Check for Mandatory Compliance Out perform Base Case ASK RIGHT QUESTIONS FOR SIMULATION (What is the output data required?) The trainer has to explain the sequence of simulation to be conducted, i.e right from the understanding the requirement of the project, generating a simulation project programme, conducting the simulation based on the programme, interpreting the results and then application of the simulation results to make design decisions/ modifications/ analysis. OR SIMPLE MODE DETAILED MODE DATA INPUT COMPUTATION DATA OUTPUT RESULT INTERPRETATION DESIGN DECISIONS

UNDERSTANDING HOW BUILDING ENERGY PERFORMANCE IS IMPROVED THROUGH SIMULATION Application of Simulation analysis and Results to achieve energy efficiency - In architectural design - In MEP design especially HVAC Case examples Acres School KK Guest House

CASE STUDY – ARCHITECTURAL DESIGN ACRE SCHOOL - CHEMBUR

ARCHITECTURAL DESIGN INTERVENTIONS BY USING ALTERNATE MATERIAL PARAMETERS Case 1: Conventional (external wall with fly ash, conventional roof) Case 2: AAC Blocks and underdeck insulation for roof Case 3: Combination of AAC blocks and flyash blocks, overdeck insulation for roof Top Roof Concrete tiles, Screed, BBM, RCC slab, Gypsum Plaster Concrete Tiles, Screed, BBM, RCC slab, Air Gap (450mm), Reflective Insulation, Gypsum Board False Ceiling Concrete tiles, Screed, Expanded Rubber Grid, BBM, RCC Slab, Gypsum Plaster U Value (W/ sqm O K) 2.0253 0.2700 0.4863 Internal Ceiling Ceramic Tiles, Screed, RCC, Gypsum Plaster 2.3149 External Wall External Cement Plaster, Fly ash blocks, Internal Plaster External cement plaster, AAC blocks Internal Plaster External cement Plaster, AAC Blocks, Internal Plaster 1.87 1.1552 Internal Wall Composition Internal Plaster, Flyash Blocks, Internal Plaster Internal Plaster, AAC Blocks, Internal Plaster 1.4202 0.9547 External Glazing ST 450 5.2379 Internal Glazing Clear Glass 5.7 This is a case example where the intention of conducting the simulation was to analyze the change in cooling energy requirement for the building and in turn the saving in energy cost, by changing the envelope material based on the thermal properties of the materials. The simulations were carried out using IES software.

Estimated Energy consumption by HVAC (in kWh) 94,762.70 90,358.00 The trainer has to explain that the simulation enable to make material choices that lead to overall energy consumption reduction. Case 1 Case 2 Case 3 Estimated Energy consumption by HVAC (in kWh) 94,762.70 90,358.00 93,473.75 Total energy consumption (in kWh), including HVAC, lighting and equipment 1,44,967.80 1,40,563.10 1,43,679.05 Energy savings in HVAC over Case 1 4.65% 1.36% Energy saving in Total Energy over Case 1 3.04% 0.89% Energy Costs savings in total energy consumption (Rs) 30,832.90 9,021.23

CASE STUDY - HVAC Design Decision KK Guest House - Bangalore

HVAC system selection This simulation was conducted to understand the change in energy consumption one the HVAC system is changed. The table shows the HVAC system description with its costs and respective benefits. The next slide shows the % savings in Electrical Consumption.

HVAC Design Interventions through simulation - The trainer explains that in this case 3 options of HVAC systems were used as 3 different cases for comparison. The simulation helped in understanding how much saving in energy possible by simply changing the HVAC systems.

SAMPLE DEMONSTRATION OF SIMULATION PROCESS Case 1 - Energy Consumption reduction through reduction in WWR. Case 2 - Energy Consumption reduction through introduction of better performing glass. Arriving which case is the best

SIMPLE MODE DATA INPUT Same for both cases SIMULATION APPLICATION DEMONSTRATION - Case 1 UNDERSTAND REQUIREMENT OF THE PROJECT The project requires to reduce energy consumption through architectural interventions. Enable to make Architectural + Services design Decisions Will reducing WWR (Window to wall Ratio) reduced overall energy demand? ASK RIGHT QUESTIONS FOR SIMULATION (What is the output data required?) Check points: Internal Heating Loads/ Energy consumption for Cooling of spaces, when Comfort conditions are at acceptable limits. The question can be can be answered by comparing results of simulations of two similar cases with Different WWRs. SIMPLE MODE Model - Same for both cases except for WWR Climate Data Schedules Lighting Systems Other Equipment HVAC System - Same System but on Autosize DATA INPUT Same for both cases

Input Data SIMULATION APPLICATION DEMONSTRATION - Case 1 Case A Case B Location (Weather File) Chennai Builtup area 1000 m2 Orientation Longer side facing North & South WWR 40% 60% Envelope Material Wall BBM (U Value - 2.122 W/m2 K) Roof RCC slabwith brick bat coba water proofing (U Value - 1.541 W/m2 K) Glazing Single Glazing Clear Glass (U Value - 3.779 W/m2 K) SHGC - 0.72 Schedules Occupancy 9:00am to 5:00pm Equipment Lighting 30% on from 9:00am to 10:00 am and 4:00pm to 5:00pm Door/ Window Opening Closed all the time HVAC system Split AC (COP - 3)

SIMULATION APPLICATION DEMONSTRATION - Case 1 Input Data Case A Case B Model with 60% WWR Model with 40% WWR

9.57% reduction in Cooling Energy Check 2 - Energy Consumption - Case B should have reduced energy consumption CASE A CASE B 9.57% reduction in Cooling Energy 10.68% reduction in Fan Energy 7.68% reduction in Total Energy

OUTPUT DATA Check 1 - Comfort - Should be achieved in both cases to achive parity in both cases (discomfort < 300 hrs per year) CASE - A CASE - B

UNDERSTAND REQUIREMENT OF THE PROJECT SIMULATION APPLICATION DEMONSTRATION - Case 2 UNDERSTAND REQUIREMENT OF THE PROJECT The project requires to reduce energy consumption through architectural interventions. Enable to make Architectural + Services design Decisions Does use of glass with lower U Value and SHGC reduce overall energy consumptions. ASK RIGHT QUESTIONS FOR SIMULATION (What is the output data required?) Check points: Internal Heating Loads/ Energy consumption for Cooling of spaces, when Comfort conditions are at acceptable limits. The question can be can be answered by comparing results of simulatons of two similar cases with Different glass materials. SIMPLE MODE Model - Same for both cases except for Glass type Climate Data Schedules Lighting Systems Other Equipment HVAC System - Same System but on Autosize DATA INPUT Same for both cases

SIMULATION APPLICATION DEMONSTRATION - Case 2 Input Data Case B Case C Location (Weather File) Chennai Builtup area 1000 m2 Orientation Longer side facing North & South WWR 40% Envelope Material Wall BBM (U Value - 2.122 W/m2 K) Roof RCC slabwith brick bat coba water proofing (U Value - 1.541 W/m2 K) Glazing Single Glazing Clear Glass (U Value - 3.779 W/m2 K) SHGC - 0.72 Single Glazing Clear Glass (U Value - 2.665 W/m2 K) SHGC - 0.497 Schedules Occupancy 9:00am to 5:00pm Equipment Lighting 30% on from 9:00am to 10:00 am and 4:00pm to 5:00pm Door/ Window Opening Closed all the time HVAC System Used Split AC (COP - 3)

SIMULATION APPLICATION DEMONSTRATION - Case 2 Input Data Case B Case C

OUTPUT DATA Check 1 - Comfort - Should be achieved in both cases to achive parity in both cases (discomfort < 300 hrs per year) CASE - B CASE - C

7.75% reduction in Cooling Energy Check 2 - Energy Consumption - Case C should have reduced energy consumption than Case B CASE C CASE B 7.75% reduction in Cooling Energy 8.46% reduction in Fan Energy 6.08% reduction in Total Energy

COMPARISION OF CASES CASE A CASE B CASE C 13.3% Saving than Case A

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