Current Features

OpenStudio SDK is constantly being improved, with a less stable developer release available every 2 weeks and a stable major release twice per year. The features that are available in the current major release are described below. To learn what is coming in the future, see the Planned Features page.

As of OpenStudio SDK Version 3.6.0

Building Constructions and Materials

Specify default materials for each type of surface and subsurface (ext walls, windows, floors, etc.) in building
Specify detailed or simple window properties
Built-in library of building constructions (walls, windows, doors, floors, etc.) for all DOE reference building types and vintages (pre-1980, 1980-2004, and 2004) plus ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
Online library of building materials and their modeling properties from ASHRAE Handbook

Building Loads

Specify people, lights, plug loads, gas loads (cooking, etc.), steam loads, internal mass, water using equipment, ventilation requirements, and infiltration
Can input loads per-area or add actual quantities to accommodate schematic and detailed design
Built in library of space types (loads and associated schedules) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004) plus ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
Can apply loads in one place (space type) and apply throughout the building

HVAC

Hot, Chilled, and Condenser Water Systems

Boilers (all fuels)
District heating and cooling
Set-temperature heating/cooling source
Single, two-speed, and variable-speed cooling towers
Single and two-speed fluid coolers and evaporative fluid coolers
Chillers (electric, absorption, indirect absorption)
Vertical and horizontal ground heat exchanger (bore fields & trenches for ground-source heat pumps)
Bypass pipes
Constant and variable speed pumps, both individual and headered
Fluid-to-fluid heat exchangers (for primary/secondary pumping and waterside economizers, etc.)
Hot, Chilled, and Condenser Water System Controls
Scheduled, OA reset, high and low with deadband, and follow OA setpoint controls
Staging of equipment (based on load range, part-load, sequential, etc.)
Solar hot water (with and without storage and integrated PV)
Pipes (indoor heat loss, outdoor heat loss, or adiabatic)
Load profile (model plant behavior with loads from a schedule)
Ice and chilled water storage
Water-to-water heat pumps

Air System Components

Supply and return plenums
Unitary equipment
Dual-duct systems
Changeover bypass (VVT) systems
Multi-stage unitary equipment (used with staged thermostats)
Outdoor air intake with economizers (all types) and damper control
Chilled water cooling coils
One-speed, two-speed, multi-speed, and variable-speed DX cooling coils
One-speed, multi-speed, and variable-speed DX heating coils (heat pumps)
Water-to-air heat pumps
Gas, electric, hot water, and DX (heat pump) heating and/or preheat coils
Variable and Constant Speed Fans
Steam humidifiers (electrically powered) used with zone humidistats
Direct and indirect evaporative coolers
Sensible and latent heat recovery
VAV-Reheat and CAV-Reheat terminals (gas, electric, and hot water reheat coils)
VAV terminals without reheat
Series and parallel fan powered boxes with reheat (all fuel types)
Diffusers
Chilled beams (active and passive)
Four-pipe induction terminals

Air System Controls

Demand-controlled ventilation
Night-cycle controls (whole system and/or terminal fans)
Scheduled, OA reset, SAT reset, and follow OA setpoint controls
Single-zone VAV system control (one control zone, many slaves)
Optimum start control

Zone-level Heating and Cooling Systems

Unit heaters (all fuels)
Unit ventilators
Energy recovery ventilators
Dehumidifiers
Low temp radiant heating (electric, variable and constant flow water)
Low temp radiant cooling (variable and constant flow water)
PTAC (DX cooling + fan + all heating fuels)
Water-source heat pump
Air-source heat pump
Exhaust fans
Four pipe fan coils (may be supplied via DOAS system)
Electric and hot-water baseboards
High temperature radiant heaters (gas and electric)
Zone-to-zone transfer air (zone air mixing)

Variable Refrigerant Flow Systems

Condenser plus zone-level terminals

Commercial Refrigeration

DX Refrigeration Systems
Cascading DX Refrigeration Systems
Fluid-filled DX Secondary Refrigeration Systems
Cases
Walk-in freezers
Compressors
Air, water, and evaporatively-cooled condensers
Liquid-suction heat exchangers and mechanical subcoolers
Heat-recovery to domestic hot water systems (desuperheater)
Heat-recovery to unitary air systems (desuperheater)

Domestic Water Systems

Hot Water Heaters (all fuels, including heat pump)
Equipment that uses warm water (showers, faucets, etc.), can specify mixed water temp
Equipment that uses cold water only
Recirculation, no pump, or instantaneous water heaters

Daylighting

Run daylighting analysis using Radiance, state-of-the-art ray-tracing daylight simulation engine without making a separate model
Lights in the EnergyPlus model controlled based on daylight available per Radiance

Custom Controls

Within EnergyPlus, advanced controls that are not built-in can implemented utilizing the EnergyManagementSystem (EMS) suite of objects. This involves defining Sensors and Actuators that interact with building parameters through Programs which are written in the EnergyPlus Runtime Language (ERL), which is based on a common building-controls language. OpenStudio SDK supports the creation of EMS programs.

Location-Specific Information

Find typical weather data and ASHRAE design conditions for most locations in the world
Use actual weather data (AMY) from a variety of vendors/sources

Economics

Full lifecycle costing (NIST Handbook 135 compliant) including built-in EIA fuel escalation rates and inflation
Adjustable analysis period length
Capital, recurring O&M, salvage, and replacement costs
Lifecycle is adjustable per-cost (IE windows can last longer than lamps)
Utility rates can include time-of-use, demand charges, ratchets, seasonal values, etc.
Utility rates for Xcel Energy CO pre-made; users pick from list

Import and Export Options

IDF import (geometry, constructions, loads, thermal zones, and schedules only)
IDF export (full model including HVAC)
gbXML import (geometry, constructions, thermal zones, and schedules only)
gbXML export (geometry, constructions, and thermal zones only)
SDD import (simulation format - full model including HVAC)
SDD export (input format - geometry, constructions, and thermal zones only)
IFC import (geometry only)

Analysis of Existing Buildings

Enter utility bills for all fuel types in building
Run model using actual weather data (AMY)
Automatically compare model results to bills and shows goodness-of-fit by fuel type
Automatically show whether goodness of fit meets common calibration standards (FEMP, ASHRAE)

Libraries

Space types (people, lights, equipment, ventilation, infiltration, schedules) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004), ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
Building constructions (walls, windows, doors, floors, etc.) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004), ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
Extensive online library of building materials from ASHRAE Handbook of Fundamentals
Extensive online library of weather files and design day conditions

Parametric Analysis

OpenStudio Measures provide reliable and repeatable mechanism to apply ECMs to models
Eliminates ambiguity and user error; all rules encapsulated in Measure itself
More than 130 Measures available online and always growing
Write Measure once and apply to many projects
Perform complex ECMs, like full HVAC replacement, easily
Edit user inputs to control how Measure modifies the model
Creates meaningful results, ready for inclusion in reports to clients.

QAQC

Measures can be used to check for common modeling errors
Users don't have to understand to use; gives expert review to junior modelers more cheaply
Automate key checks for Utility Regulators to keep up quality
Lower time spent by reviewers on mundane checks; frees time to focus on real issues

Reporting

Measures can be used to create custom reports in HTML format (view in any web browser)
Allows users to quickly visualize and summarize data for different audiences
Reports are shareable via email
Reports can be simple or highly interactive

Cloud Computing

Any user with an Amazon account can run simulations on cloud with 1 click
Very cheap vs. engineer's time (16 simulations in parallel for ~$2.00/hr)
Can run up to 300 simulation in parallel (costs scale in 16-processor increments)
Enables small firms to access cloud computing without upfront hardware costs

Online database called BCL (Building Component Library) can be used to share Measures
BCL can be used to share building components
Instantaneous world-wide distribution and updating of content
Allows Utilities to ensure uniformity and best-practices across many EC firms

Documentation

Interactive PDFs describing each Application
Measure writing guide
Lifecycle costing guide
Documentation of all modeling commands (SDK) online, updated bi-weekly

Applications

The following applications are available to work with the OpenStudio SDK installation:

Data Viewer

View the detailed timeseries simulation results
Create interactive line graphs and heat maps

Parametric Analysis Tool (PAT)

Select a baseline model to serve as the starting point for a parametric analysis
Drag in Measures and set their input values
Select combinations of Measures to run
Run the simulations locally or on the cloud
View a high-level comparison of the simulation results or dig into the detailed reports