Energy Modeling Training: Introduction to OpenStudio · PDF fileEnergy Modeling Training:...
Transcript of Energy Modeling Training: Introduction to OpenStudio · PDF fileEnergy Modeling Training:...
Energy Modeling Training: Introduction to OpenStudio/E+
Yung Nguyen, EIT, BEMP, CEM
Celia King-Scott, PE, BEMP
Learning Objectives
• Understand where and how energy modeling is used
• Be able to run a simple model created from OpenStudio
• Have a basic understanding of work flow • Have an understanding of energy model
output
Module of the Day
• Introduction to Energy Modeling & Software • Workflow within OpenStudio & EnergyPlus Break • Model Practice 1: Templates • Model Practice 2: Geometry • LUNCH • Model Practice 3: Assign Attributes • Model Practice 4: HVAC Systems & Simulations Break • EnergyPlus Interface • Reporting & Self-Check
Introduction: What is an Energy Model? A computer simulation that calculates the energy usage of a building based on the principle of building science and vast amount of data inputs.
Thermal mass properties of walls, roof, floor, slab, interior walls
Thermal properties of windows, shading coefficient
Lighting intensities, heat emitted by lighting, cooling needed to offset the heat emitted
Plug load intensity per area type, plug load radiation fraction
Heating & Cooling: equipment size, part performance curve, fan size, fan performance curve, coil types, plant type, static pressure loss, control strategies including: outdoor reset, demand matching, demand control ventilation, etc.
Indoor Air Requirement: room types, air changes required
Space types, area, height, ceiling height/ plenum
Introduction: Why Do You Need a Model? • Interactive effects – modeling whole buildings
taking account of how a reduction in an end use would affect another end use.
• Example: What happens when you reduce the lighting load by 50%? What end uses are affected?
Introduction: When Do You Use a Model?
NEW CONSTRUCTION EXISTING BUILDINGS
NEW CONSTRUCTION EXISTING BUILDINGS
• To establish cost/benefits for design decision in high performance buildings
• Understand integration of complex systems
• Establish energy budgets for operation
• Permitting/LEED
• New Construction Whole Building Design Incentive
• To determine savings, cost, and benefits based on changing operation strategies
• Often used in major capital projects to determine the best life cycle cost options
• Used in Retro-commissioning, Monitoring Based Commissioning, ASHRAE Level 3 Audits, etc.
• Help facilities manager determine the ROI and plan projects internally
Introduction: When Do You Use a Model?
NEW CONSTRUCTION
Introduction: When Do You Use a Model?
Introduction: How Do You Model? • Evaluate the software of choice • Taking this training • Practice, practice, practice • Know what to look for • Become a master modeler!
Introduction: Software History
• DOE-2 engine was a plain program used to analyze energy usage. DOE-2 later supports eQuest, the graphic user interface.
• DOE stops supporting DOE-2 development and switches gears to EnergyPlus engine (meant to unite BLAST and DOE-2 best features together).
• Note: There’s a difference between ENGINE and
SOFTWARE INTERFACE (GUI).
Introduction: The Future
Introduction: Software Market
3D+
RES NON-RES
Introduction: Software Market
3D+
FREE NOT FREE
Introduction: Software Market
3D+
FORUM PAID TECH SUPPORT
Introduction: What is EnergyPlus?
IDF EDITOR
E+ ENGINE
INPUT
Input Data
Project.idf
Weather
File
Introduction: How Do You Work in E+?
NOTEPAD
IDF EDITOR
Introduction: EPlus Engine & GUIs
ENERGYPLUS is an ENGINE
NREL Developed
GUI for EnergyPlus
GUI for E+
California Compliance Software
Run on E+
THESE ARE THE GUIS
NotePad or IDF Editor
Introduction: Why OpenStudio?
vs
DRAG & DROP TEXT
Introduction: Why OpenStudio/ E+? • Capabilities Highlight
– Abilities to model many HVAC systems
– Data output for many variables at any intervals (cd vs hard drive)
– Special systems (refrigeration, electro chromatic windows)
– OpenStudio measures (automation of energy modeling tasks)
• Limitations – Rely on Unmet Hours Forum
– Very high learning curve for beginner
– Requires high troubleshooting skills
– Does not have component module offered by other software
– Long run time depend on model complexities
Icebreaker
Workflow: Building the Model
OpenStudio
MEASURES SKETCHUP
IDF Editor NOTEPAD
Workflow: Programs Set Up Time
OpenStudio
MEASURES SKETCHUP
MAKE 2017
IDF Editor NOTEPAD
OS 2.1.0
EnergyPlus v8.7
Workflow: Programs Set Up Time
Workflow: Tips & Tricks
1. Always save different versions 2. You may want to name your surfaces and
sub-surfaces (walls & windows) 3. Google your errors / Unmet Load Hours
Forum 4. Practice. Practice. Practice.
Workflow: OpenStudio Interface
REF: http://nrel.github.io/OpenStudio-user-documentation/img/pdfs/openstudio_interface_quickstart.pdf
Workflow: OpenStudio Interface
REF: http://nrel.github.io/OpenStudio-user-documentation/img/pdfs/openstudio_interface_quickstart.pdf
Workflow: OpenStudio Interface
REF: http://nrel.github.io/OpenStudio-user-documentation/img/pdfs/openstudio_interface_quickstart.pdf
Workflow: OpenStudio Interface
REF: http://nrel.github.io/OpenStudio-user-documentation/img/pdfs/openstudio_interface_quickstart.pdf
Workflow: Building the Model
OpenStudio
MEASURES SKETCHUP
IDF Editor NOTEPAD
1 WAY STREET
2 WAYS STREET
ADVANCE
BREAK
Practice Model Workflow
1. Make templates
2. Build geometry
3. Add refinements
4. Last resort
Practice 1: Templates
• OpenStudio uses templates for different building types. When you build geometry, you apply the space to a template as you go, so that if you need to change something later on, it can do a global change all at once.
• Approach to building model is SYSTEMATIC.
Practice 1: Templates Open OpenStudio. Go to File > Load Library
This will load ASHRAE 90.1 profiles and other standards’ general assumptions.
Practice 1: Construction Template
Materials •Insulation •Layers •Gypsum
Construction •Exterior Wall 1
•Roof Assembly 2
Construction Set
• Roof + Walls + Windows + All Other Surface
• Need Thermal Properties of Layer
• Need Assembly Properties
• Combination of Assembly
Practice 1: Construction Template
1. Materials – R30 Insulation
2. Construction Assembly
Practice 1: Construction Template 3. Construction Set
Practice 1: Schedule Template
Schedule •Design Days •Run Profile Priority / Default
•% , Fractional
Schedule Set
• People + Lighting + Operation Schedule + More
• Combination of Schedule
Practice 1: Schedule Template
Practice 1: Schedule Template
Practice 1: Internal Gains
Typical important ones Plug load is not really regulated, but there are typical values / reasonable assumptions suggested from ASHRAE 90.1 User Manual or other guiding documentation based on space types
Practice 1: Space Type Template
Template inception: Templates within a template.
Practice 1: Space Type Template
Template inception: Templates within a template.
Systems
Thermal Zones
Space Types
Schedule / Construction
/ Internal Gains
Practice 1*: Thermal Zone
Best Practices Tip •Thermal zones should follow HVAC Designer rule of thumb •Perimeter Zones and Interior Zones •Drastic different room loads will have different HVAC needs – separate them •Group similar zones and equipment together
BREAK
Practice 2: Geometry
30’
15’
10’
10’
10’
5’
5’
5’ 25’
Zone 1 Office
Zone 2 Office
Zone 3 Reception Zone 4
Corridor
Zone 5 Conference
30’
1st Floor 2nd Floor
North & South East & West
18’
4’ 6’
6’
4’ 2’ 4’ 2’ 2’
1st Floor
North & South 2nd Floor
18’
4’ 6’
2’
East & West
6’
4’ 7’ 2’
Practice 2: Geometry
Practice 2: Geometry
1
2 Double Click
3 Draw
4 Extrude OR
METHOD 1: Create Space by Hand
Practice 2: Geometry Useful default shortcuts in SketchUp:
P H
Space L M
Extrude Hand Select Line (Draw Pencil) Move
Practice 2: Geometry
METHOD 2: Create Space by “Create Spaces from Diagram”
1 Draw
2 Create Spaces from Diagram
Practice 2: Geometry
Practice 2: Geometry
Boundary Conditions Tan – Ground Blue - Air
Constructions Tan – Walls Red – Roof Transparent Blue - Windows
By Space By Thermal Zones By Construction
Example Practice 2: Geometry
Launch OS
Show Errors
Filter
Inspector
Create Spaces from Diagram
Attributes To Space
Surface Matching
Create Space
Most Useful Icons
Practice 2: Geometry Surface Matching & Intersect
• OpenStudio requires adjacent surfaces to have EXACT same area.
• Match and Intersect tool draws new geometry (for more complicated shapes).
LUNCH BREAK
Practice 3: Assign Attributes Definitions to Templates
Practice 3: Assign Attributes
Practice 3: Assign Attributes
• Inspector Tool • Can assign name, space type,
construction template, schedule template, thermal zone
• Can only edit one object at a time even if you select multiple objects
• Filter Tool • Can filter out 3D components with
criteria
Icebreaker
Practice 4: HVAC System
Zone 1 Office
Zone 2 Office
Zone 3 Reception Zone 4
Corridor
Zone 5 Conference
AC-1 AC-2
AC-3 AC-4
Packaged Rooftop Units • 3.5 COP • Economizer Dry Bulb
Practice 4: HVAC System
1. Assign Set Point in Thermal Template
2. Create Air-loop System
Practice 4: Before Simulation Download weather file from: https://energyplus.net/weather-region/north_and_central_america_wmo_region_4/USA/AZ
Phoenix (TMY3) •epw – Annual Weather Data •ddy – Design Day Data (for sizing)
Practice 4: Before Simulation
Practice 4: Simulate!
BREAK
When Export to EnergyPlus…
• It’s a one way street. Not easy going to back to OpenStudio.
• Only export to E+ to use the EnergyPlus Energy Management System (EMS) or things OpenStudio can’t do.
EnergyPlus Interface
Find and launch the program EP-launch.exe located in the main EnergyPlus directory Usually C:\EnergyPlusVXXX
EnergyPlus Interface
.IDF Input File
.epw Weather File
EnergyPlus Interface
• Click the ‘Simulate’ button to begin running the simulation
• EnergyPlus should appear in an MS-DOS window
EnergyPlus Interface
• ALWAYS look at the ERR file when the simulation has completed successfully!
• There are warnings that can help you troubleshoot results and are important to address!
Software reports: Parallel OPENSTUDIO ENERGYPLUS
Annual & Monthly Overview Annual Building Utility Performance Summary (ABUPS)
Air & Plant Loops Detail System Summary (shows unmet hour load)
Site and Source Summary Energy Cost by Fuel Source
HVAC Load Profiles Equipment Summary System Summary
Envelope Envelope Summary
Software Reports: Good & Bad OPENSTUDIO ENERGYPLUS
Nice graphs / visually pleasing Highly detailed, know the autosize values & user inputs values
Summarize key facts Harder to Navigate / Hunt Information
Lack details for a deep review Excel Friendly
Less friendly to export Map-able to custom reports
Overall useful for quick QC Overall useful for detailed QC
Self-Check Tips
• Organize your zones / system early on will serve you well
• Reduce # of spaces / surface areas for run time
• “All models are false, but some are useful” • Benchmark to see if your performance is in
the right ballpark • Refer to Unmet Load Hour forums for
questions or join your local energy modeling club
Self-Check Tips
• Verify that rule of thumb expectations • Take into account the differences in heating
and cooling loads between the baseline and proposed, based on implemented EEMs: – Increased insulation – High performance fenestration/shading – Thermal mass – Building Orientation
Self-Check Tips • Verify where the savings are coming from, i.e., which end-
use(s) has the greatest reduction in energy consumption • Focus on elements where energy savings don’t appear to be
justified • What end-use consumption holds more weight as far as %
of total consumption?
Key Takeaways
Learning Objectives: • Understand where and how energy modeling
are used
• Be able to run simple model created from OpenStudio
• Have a basic understanding of workflow
• Have an understanding of energy model output
Key Takeaways
• When you see the same error over and over again with over a thousand variables to change… chances are it’s somewhere in HVAC and secondly, keep sane by taking a walk.
THANK YOU!