Visualization Daylighting Metrics Annual Glare Maps. DIVA Approach

Transcription

1 The Science Behind DIVA And how to present it to your clients Visualization Daylighting Metrics Annual Glare Maps Energy Considerations Radiation Map Christoph Reinhart DIVA DAY Oct 19 th 2012 Point in Time Glare Operational Energy DIVA Approach DIVA links validated performance simulation engines to Rhino and thus gives users access to meaningful, actionable data from the beginning of a project. We believe this early integration empowers creative, consequential, and lasting design interventions. Grasshopper Rhino Model Visualizations Radiance Visual Comfort Evalglalre Climate based Metrics Daysim Radiation Maps GenCumulativeSky Annual Glare Maps Daysim Thermal Loads EnergyPlus 1

2 BPS Today Building 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 Energy Solar Radiation Daylight Return on Investment Occupant Comfort Walkability A field in transition BPS Today 2

3 DIVA s specific focus areas are daylighting, glare, occupant comfort and operational energy use. DIVA Approach to Daylighting Figure from Daylighting Manual (Reinhart) 3

4 What is the relationship between daylight availability and building massing, i.e. how much of a building can be daylit depending on its overall shape and surrounding context? Daylight Availability and the Daylit Area How can we determine the daylit area in a space? Source Daylighting Manual (Reinhart) 4

5 Daylight Autonomy Source Daylighting Manual (Reinhart) Daylight autonomy (DA) is a daylight availability metric that corresponds to the percentage of the occupied time when the target illuminance at a point in a space is met by daylight. According to the IESNA a point is daylit if the Daylight Autonomy at 300 lux is above 50%. We expect DA to be adopted by LEED and other Green building Standards. Ok, that s what the computer tells us. How well does daylight autonomy relate to occupant assessments of spaces? 5

6 Carpenter Center Study Source Daylighting Manual (Reinhart) C F Reinhart and D Weissman, "The Daylit Area - Correlating architectural student assessments with current and emerging daylight availability metrics", Building and Environment, 50, pp , Daylight Autonomy Comparison Daylight Autonomy 300lux [50%] Mean Occupant Assessment Comparison for this one space encouraging. 6

7 DA 150lux [50%] DA 300lux [50%] DA 500lux [50%] MIT (USA) Miami University (USA) Parsons (USA) dynamic interaction of light and building form Iowa (USA) Paraiba (Brazil) UFSC (Brazil) Concordia (Canada) Idaho (USA) Ok, I am signed up for Daylight Autonomy. How can I calculate it? 7

8 Significance of the Simulation Engine Comparison of a Best Practice Model using Ecotect-Split-Flux vs. Radiance Best Practice Model Ecotect Mean Daylight Factor = 0.55% Percentage of floor area >2% = 0% Best Practice Model Radiance Mean Daylight Factor = 2.59% Percentage of floor area >2% = 42% dramatic difference between both engines due to wall thickness Paper: Ibarra D, Reinhart C F, "Daylight factor simulations - 'How close do simulation beginners 'really' get?, Proceedings Building Simulation 2009 Validation Studies for Radiance/Daysim Light. Res. & Technology Mardaljevic, 1995 Daylight Autonomy [%] Energy & Buildings Reinhart, Walkenhorst 2001 measured simulated climate Data: i Energy & Buildings Reinhart, Andersen illuminance threshold [lux] The Radiance/Daysim daylight simulation program can efficiently and reliably model annual illuminance time series with a mean relative error of 20%. 8

9 Simulation Checklist 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 Ongoing Daysim Activities Fully documented API supported by the US DOE. We are giving up the Daysim JAVA GUI. 9

10 Ongoing Daysim Activities LBNL & Penn State: Greg Ward s new three phase Methods is currently being fully integrated into DAYSIM. This will allows users to run annual daylight calculations BTDF functions from Windows 6 in Daysim. Penn State: Addition of explicit electric lighting calculations in Daysim. This will allow users to specify and model actual luminaries and place photocell sensors in Daysim and link them to an annual electric lighting calculation. Fraunhofer ISE: Linking of forward raytracing (photon mapping) into Daysim. Test version completed last week. Once fully tested and matured, we will be adding these new functionalities to DIVA. DIVA Approach to Daylighting Figure from Daylighting Manual (Reinhart) 10

11 Multidirectional Time-Lapse Simulation DGP yields most plausible results in these spaces. Design: Jeff Niema Paper J A Jakubiec, C F Reinhart, The Use of Glare Metrics in the Design of Daylit Spaces: Recommendationssz for Practice", Lighting Research and Technology Concept of the Adaptive Zone Annual DG Calculation: Fixed view looking forward Annual DG Calculation: +/ 45 degrees rotational freedom The concept helps to quantify the benefits of flexible furniture Design: settings Jeff etc. Niema sz 11

12 Occupant Behavior Monitoring User Behavior architecture: Meier-Weinbrenner-Single, Nürtingen Paper: Reinhart C F, Voss K, Monitoring manual control of electric lighting and blinds. Lighting Research & Technology, 35:3 pp ,

13 Monitoring Setup in the Offices Illuminance Temperature occupancy HOBO data logger Switch-On Probability (II) switch-on probability at arrival Hunt 1978 Lamparter minimum work plane illuminance [lux] 13

14 Lightswitch - Manual Lighting Control Is work place already occupied? Are lights switched on? Are lights switched on? Does occupant arrive? 1 Does occupant arrive? Does occupant leave? Does occupant leave? stochastic process: switch on probability (Fig. 7-5) switch-on probability Is there an occupancy sensor? Hunt Lamparter stochastic process: intermediate switch on probability (Fig. 7-7) stochastic process: Pigg s switch off probability with or without occupancy sensor (Fig. 7-5) 0 0 Has the 100room been deserted for longer minimum than sensor work plane illumiance [lux] delay time? Switch lights on Switch lights off Switch lights on Switch lights off Daylighting Dashboard Question: Should I specify blinds or not? % Occupied hours Daylit Area: 73% of the space 44% of the space Potential glare: 50% of the year no glare View: 100% 50% Paper Reinhart C F, J Wienold, The Daylighting Dashboard - A Simulation-Based Design Analysis for Daylit Spaces. Building and Environment, :

15 Daylighting vs. Thermal Model workspace with high visual comfort Once zone model with all surface facing outward. The link between the daylighting model and the thermal model is the schedule file. Daylighting Dashboard Question: Should I specify blinds or not? % Occupied hours Daylit Area: 73% of the space 44% of the space Potential glare: 50% of the year no glare View: 100% 50% 15

16 Thank You Contact Christoph Reinhart Associate Professor Massachusetts Institute of Technology MIT Sustainable Design Lab Karthik Dondeti (MIT) Timur Dogan (MIT) Diego Ibarra (GSD) Alstan Jakubiec (MIT) Holly W Samuelson (GSD) John Sullivan (MIT) Tarek Rakha (MIT) Solemma LLC Alstan Jakubiec Kera Lagios Jeff Niemasz Jonnie Sargent