Christoph ReinhartRoyal Academy of Engineering – December 11 2013Christoph ReinhartRoyal Academy of Engineering – December 11 2013

Environmental Performance Simulation From evaluating performance to suggesting new formsfor buildings and neighborhoods

Massachusetts Institute of TechnologyDepartment of ArchitectureBuilding Technology Program

Rules of Thumb

Urban Modeling Mobility

Microclimate Cambridge Solar Map

Wiki says: The collection of scientific knowledge that focuses on the

analysis and control of the physical phenomena affecting buildings.

What is Building Science?

Buildings account for roughly a third of carbon emissions.

We spend 90% of our time indoors.

What are key drivers?

Research Hypothesis

q Technologies are in place to design and construct affordable, resource-efficient and comfortable buildings.

q Current design practice and education relies on a non-standardized and mostly not validated design analysis workflows.

“Our research goal is to change current sustainable design practice by developing, validating and testing workflows and metrics that lead to

improved design solutions as far as occupant comfort and health as well as building energy use are concerned. The premise of this work is that an

informed decision is a better decision.”

Sustainable Design Lab @ MIT

Carlos CerezoTimur DoganDiego Ibarra (GSD)Alstan Jakubiec Aiko NaganoChristoph Reinhart Cody RoseTarek RakhaJulia Sokol

Building Performance SimulationBuilding Performance Simulation: An computer-based attempt to model the various energy and mass flows within a building in order to predict one or several performance aspects of a design.

Operational EnergyOperational Energy Solar RadiationSolar Radiation DaylightDaylight

Return on InvestmentReturn on Investment Occupant ComfortOccupant Comfort WalkabilityWalkability

Today’s PresentationFrom evaluating performance to

suggesting new forms

q Environmental performance simulations are now capable of predicting the physical performance of commonly used building typologies and technologies.

q Parts of this analysis can be done by architects and planners themselves. Is this true/desirable?

q We can increasingly expand our analysis to the urban/neighborhood realm.

Why Environmental Performance Simulation?

q To demonstrate code compliance and to reduce risk.

q To compare different design variants.

Do today’s simulation programs work?

ASHRAE thinks so.

ASHRAE 140 -2007 Standard Method for the Evaluation of Building Energy Analysis Computer Programs

Purpose of the Standard

q Analyzing and diagnosing buildingenergy simulation software usingsoftware-to-software and software-to-analytical-solution comparisons.

q Checking a program against a previousversion of itself after internal codemodifications such as an algorithmicchange.

Uncle Sam thinks so, too.

Tax Deduction Information

Under IRS rules, taxpayers' building energy use performance must be calculated using software that has been tested according to ANSI/ASHRAE Standard 140 to qualify for tax deductions.

Comparison of measured and simulated energy use for 97 LEED Buildings

PaperH W Samuelson, A Lantz and C F Reinhart, "Non-technical barriers to energy model sharing and reuse", Buildingand Environment, 54, pp. 71-76, 2012.

Model uncertainty from weather, infiltration rate, usage scheduleand occupant behavior.

But, models can be calibrated…

H W Samuelsona, A Ghorayshib and C F Reinhart, Analysis of a Simplified Building Energy Model Calibration Procedure for 18 Real-World Case Studies (in preparation)

climate Data: i

Light. Res. & Technology Mardaljevic, 1995

Accuracy of Daylight Simulations

Energy & Buildings Reinhart, Walkenhorst 2001

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0 200 400 600 800 1000illuminance threshold [lux]

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Energy & Buildings Reinhart, Andersen 2006

The Radiance/Daysim daylight simulation program can efficiently andreliably model annual illuminance time series with a mean relative errorof 20%.

Papers:§ Reinhart C F, Andersen M, “Development and validation of a Radiance model for a translucent panel”, Energy and Buildings 38:7pp. 890-904, 2006§ Reinhart C F, Walkenhorst O, “Dynamic RADIANCE-based daylight simulations for a full-scale test office with outer venetianblinds.” Energy & Buildings, 33:7 pp. 683-697, 2001

Today’s PresentationFrom evaluating performance to

suggesting new forms

q Environmental performance simulations are now capable of predicting the physical performance of commonly used building typologies and technologies.

q Parts of this analysis can be done by architects and planners themselves. Is this true/desirable?

q We can increasingly expand our analysis to the urban/neighborhood realm.

√

Teaching Simulations

How close do ‘simulation novices’ get?

McGill – School of Architecture Crit Room 102- Best Practice Model

- error analysis of 69 student models of a sidelit space- comparison of simulation results using Ecotect-Split-Flux and Radiance

Paper: Ibarra D, Reinhart C F, "Daylight factor simulations - 'How close do simulation beginners 'really' get?“, Proceedings Building Simulation 2009.

69 Student Models

q Ecotect results lie over and under Radiance resultsq Enormous range of results.

SimulationChecklist

Book Chapter: Reinhart C F, “Simulation-based Daylight Performance Predictions“ in Building Performance Simulation for Design and Operation, Editors J Hensen and R Lamberts, Taylor & Francis, 2011

Spring 2012 MIT 4.430 Daylighting

Spring 2012 MIT 4.430 Daylighting

q Simulation of 10.485.q Practicing good simulation habits.q Building trust in one’s own modeling skills.

How do we reach the architects not interested in taking electives on

simulation?

Simulation Games

HypothesisBeing able to read thermal simulation results and to adapt one’s design accordingly has become an essential skill for graduating and practicing architects.

Being able to read thermal simulation results and to adapt one’s design accordingly has become an essential skill for graduating and practicing architects.

Why?The alternatives for architects are to effectively ignore simulation output or to have the modeler take over key design aspects of the building. (Both alternatives are undesirable for architects.)

NoteEngineers, this does not mean that the architects know how to do the simulations themselves.

The Game …

Human Cluster [Experts] Simulation Queue

Searching for the winning combination…

C F Reinhart, T Dogan, D Ibarra and H W Samuelson, "Learning by doing - Teaching energy simulation as a game", Journal of Building Performance Simulation, October 2011.

Simulation Order Form

Provided by Modeler

q EUIs of the 10 final designs were 22–31% below the base variant.q Building massings chosen by the different groups diverged.

Results: Final Designs

“Today building science was definitely not boring.”

Today’s PresentationFrom evaluating performance to

suggesting new forms

q Environmental performance simulations are now capable of predicting the physical performance of commonly used building typologies and technologies.

q Parts of this analysis can be done by architects and planners themselves. Is this true/desirable?

q We can increasingly expand our analysis to the urban/neighborhood realm.

√

√

Framework for Daylighting

Paper: C F Reinhart and J Wienold, "The Daylighting Dashboard - A Simulation-Based Design Analysisfor Daylit Spaces", Building and Environment, 2011.

Figure from Daylighting Handbook (Reinhart)

Daylighting Dashboard

Paper§ Reinhart C F, J Wienold, “The Daylighting Dashboard - A Simulation-Based Design Analysis for Daylit Spaces”. Building andEnvironment, 2011 46:2 386-396

Daylit Area: 73% of the space 44% of the space

% Occupied hours

Potential glare: 50% of the year no glare View: 100% 50%

Question: Should I specify blinds or not?

DIVA for Rhino

Radiation MapsRadiation MapsClimate-based MetricsClimate-based MetricsVisual ComfortVisual ComfortRadianceRadiance

Rhino ModelRhino Model

Paper: § K Lagios, J Niemasz and C F Reinhart, "Animated Building Performance Simulation (ABPS) - Linking Rhinoceros/Grasshopper with

Radiance/Daysim", SimBuild 2010, New York City, August 2010§ J A Jakubiec and C F Reinhart, DIVA-for-Rhino 2.0: Environmental parametric modeling in Rhinoceros/Grasshopper using

Radiance, Daysim and EnergyPlus, Building Simulation 2011, Sydney, November 2011

Annual Glare MapsAnnual Glare Maps Thermal LoadsThermal Loads

GrasshopperGrasshopper

VisualizationsVisualizationsEvalglalreEvalglalre DaysimDaysim GenCumulativeSkyGenCumulativeSky DaysimDaysim EnergyPlusEnergyPlus

Animated Building Performance Simulation

Simulation: J Niemasz and K Lagios

Environmental Performance combined with a Genetic Algorithms

Determine a box shape with maximum enclosed volume and annual solar radiation exposure in Boston (Niemasz)

This looks a bit like trying to have monkeys play Shakespeare. Can we do better?

SHADERADE - Generating the Next Generation of Shading Systems

Design: Jeff Niemasz

Conventional Shading

Static Exterior Shading: SHADERADE

Surround Shade

Paper: J Sargent, J Niemasz, C F Reinhart, “SHADERADE: Combining Rhinoceros and EnergyPlus for the design of static exterior shadingdevices”, Building Simulation 2011, Sydney, November 2011.

Static Exterior Shading: SHADERADE

Surround Shade

Once the volume has been assessed, any surface within its bounds can be visualized:

The Shaderaded Aquatower

J Sargent & J Niemasz

A General Circulation Model (GCM) is a mathematical model of the general circulation of a planetary atmosphere or ocean. [Wikipedia]

The IPCC Working Group III developed storylines which represent a potential range of different demographic, social, economic, technological and environmental developments (IPCC 2000).

Climate Change Predictions

How large is the Effect?

Harvard University – Gund Hall DesignBuilder model

Gund Hall nowq 33 Zone E+ modelq 1990 TMY2 weather data for Boston

Samuelson, Holmes, Reinhart 2011

Case Study: Gund Hall now and thenq 33 Zone E+ modelq 1990 TMY2 weather data for Bostonq predicted 2080 weather data for the IPCCCA2 scenario (medium to high emissions scenario).

36% less heating

45% more cooling

Linking Future Climate Files with Future Prices

q The basic idea of the paper is to link 7 of the 22 energy price projections from the 2009 Energy modeling Forum (EMF-22) to the four climate change projections from the 3rd IPCC Assessment Report (TAR).

q The matching is realized via the Radiative Forcing (RF) of the different scenarios. RF is the change in net irradiance at the top of the tropopause compared to the year 1750.

Data Source: Economic Insights from Modeling Analyses of H.R. 2454 — the American Clean Energy and Security Act (Waxman-Markey); Pew Center for Global Climate Change

Case Study: Office Building in BostonGeneric 1980s office building, floor area 5000m2, 3 stories.q Baseline: Building left as is.

q Minimum: Upgrade so that the building meets ASHREA 90.1-2004 (more efficient HVAC and windows (inoperable).

q Medium: Same as previous but add mixed-mode ventilation & solar shading.

q Advanced: Same as previous but double all insulation levels.

$89,000upgrade ∆ cost

$183,000upgrade ∆ cost

$255,000upgrade ∆ cost

Case Study: Cumulative Energy Costs

Paper: S H Holmes and C F Reinhart, Assessing future climate change and energy price scenarios for institutional building investment and HVAC operation, Building Research and Information, 41:2, pp. 209-222, 2013.

Case Study: Cumulative Energy Costs

q IRR highest for minimum upgrade. (It is tough, energy is cheap in this country.)

q Cooling dominated climates have higher IRRs. This does not necessarily translate into actions today.

Urban ModelingC Reinhart, C Cerezo, J A Jakubiec, T Dogan, T Rakha

Context - From homo sapiens to homo urbanus

Grimond, J, 2007, The world goes to town, The Economist, May 5th 2007

Source: WIKI UN 2010 Projections

q Industrial Revolution - 3% city dwellerq 2008 - 50% city dwellerq 2030 60% city dweller 1.7 billion more than today

Our task is to house 1.7 billion new city dwellers in 17 years or two

million a week.

How can we do this?Housing for 2 million in Boston corresponds to about 80,000 buildingsweek.

q Dramatically increase the number of qualified simulationists

q Introduce significant economies of scale = urban modeling

Informal Settlement in Rio

How do we live?

Suburbs in Shanghai

Back Bay, Boston Forum Vaubin, Freiburg, GermanyOperational Energy Mobility Comfort Daylight Costs Embodied Energy

Operational Energy Mobility Comfort Daylight Costs Embodied Energy

Goal

To develop an urban modeling platform to design and improve new and existing neighborhoods regarding multiple

measures of urban sustainability including operational energy use, daylighting, outdoor comfort and sustainable

transportation.

Combining Big Data and BPS

Photo of the MIT Campus (Google Maps).

LiDAR Data of the MIT Campus

3 dimensional point cloud (126 million points).

3D Model of the MIT Campus

Generation of a 3D model through surface triangulation.

Solar Radiation Map

Cumulative annual solar radiation.

Mapdwell – MIT spinoff

umi

Plug-in for NURBS Modeler Rhinoceros 5

Workflow

Download atwww://UrbanModeling.net

Massing Model

How does it work? User Perspective

1. Design a building form 2. Assign energy templates and fenestration information

3. Simulation model constructed

Visualizing umi-Thermal Simulation Results

Export and simulation time: ~20 minutes with parallel processing (8 GHz-hours).

Whole city electricity, gas and carbon emissions

Valuable input for district heating and cooling providers.

umi - Outdoor Comfort

-> Daysim/Radiance -> E+ Weather File

Hourly Solar Radiation:

umi - Outdoor ComfortTair > 28 °C & dir solar Tair < 5 °C & without dir solar

hours / yr hours / yrSource: Timur Dogan

umi - Mobility

Source: Tarek Rakha

umi - Daylighting

Hourly Exterior Solar Radiation*

Interior light solver **

Dogan, Reinhart, Michalatos, URBAN DAYLIGHT SIMULATION CALCULATING THE DAYLIT AREA OF URBAN DESIGNS, SimBuild2012

Umi - Daylighting

Calculated in less than 30 minutes including model setup. Source: Timur Dogan

umi – Embodied Energy

Source: Carlos Cerezo

Today’s PresentationFrom evaluating performance to

suggesting new forms

q Environmental performance simulations are now capable of predicting the physical performance of commonly used building typologies and technologies.

q Parts of this analysis can be done by architects and planners themselves. Is this true/desirable?

q We can increasingly expand our analysis to the urban/neighborhood realm.

√

√

√

Closing Thoughts

q Building Science and BPS have reached a level of professional maturity and the results of BPS increasingly draw attention form outside of the traditional AEC community.

q More comprehensive teaching of Building Science is required that combines validated rules of thumb with simulations and case study analysis.

q We need to collect and publicize the energy use of all buildings and rate a building according to its performance with respect to its peers.

Thank youContactChristoph ReinhartAssociate Professor MITEmail: creinhart@mit.edu

MIT Sustainable Design LabCarlos CerezoTimur DoganDiego Ibarra (GSD)Alstan JakubiecNathaniel JonesAiko NaganoKrista PalenTarek RakhaJulia Sokol

SolemmaAlstan JakubiecKera LagiosJeff NiemaszChristoph Reinhart Jon Sargent

AlumniSeth Holmes, Karthik Dondeti, Elliot Glassman, Cynthia Kwan, Rohit Manudhane, Rashida Mogri, Azadeh Omidfar, Debashree Pal, Tiffany Otis, Holly W Samuelson, Jennifer Sze, John Sullivan, Nari Yoon

Today – Launch of the Washington DC Solar Map