Capabilities¶
ERI Capabilities¶
The following ERI Standards and Addenda are currently available:
- ANSI/RESNET/ICC 301-2014© “Standard for the Calculation and Labeling of the Energy Performance of Low-Rise Residential Buildings using an Energy Rating Index”.
- ANSI/RESNET/ICC 301-2014 Addendum A-2015, Domestic Hot Water Systems, January 15, 2016
- ANSI/RESNET/ICC 301-2014 Addendum E-2018, House Size Index Adjustment Factors, February 1, 2018
- ANSI/RESNET/ICC 301-2014 Addendum G-2018, Solid State Lighting, February 2, 2018
Modeling Capabilities¶
The following building features/technologies are available for modeling:
- Enclosure
- Attics
- Vented
- Unvented
- Conditioned
- Radiant Barriers
- Foundations
- Slab
- Unconditioned Basement
- Conditioned Basement
- Vented Crawlspace
- Unvented Crawlspace
- Ambient
- Garages
- Windows & Overhangs
- Skylights
- Doors
- Attics
- HVAC
- Heating Systems
- Electric Resistance
- Furnaces
- Wall Furnaces & Stoves
- Boilers
- Cooling Systems
- Central Air Conditioners
- Room Air Conditioners
- Heat Pumps
- Air Source Heat Pumps
- Mini Split Heat Pumps
- Ground Source Heat Pumps
- Thermostat Type
- Ducts
- Heating Systems
- Water Heating
- Water Heaters
- Storage Tank
- Instantaneous Tankless
- Heat Pump Water Heater
- Indirect Water Heater (Combination Boiler)
- Tankless Coil (Combination Boiler)
- Hot Water Distribution
- Recirculation
- Drain Water Heat Recovery
- Low-Flow Fixtures
- Water Heaters
- Mechanical Ventilation
- Exhaust Only
- Supply Only
- Balanced
- Energy Recovery Ventilator
- Heat Recovery Ventilator
- Central Fan Integrated Supply
- Photovoltaics
- Appliances
- Clothes Washer
- Clothes Dryer
- Dishwasher
- Refrigerator
- Cooking Range/Oven
- Lighting
- Ceiling Fans
Accuracy vs Speed¶
The EnergyPlus simulation engine is like a Swiss army knife. There are often multiple models available for the same building technology with varying trade-offs between accuracy and speed. This workflow standardizes the use of EnergyPlus (e.g., the choice of models appropriate for residential buildings) to provide a fast and easy to use solution.
The workflow is continuously being evaluated for ways to reduce runtime without significant impact on accuracy. A number of such enhancements have been made to date.
There are additional ways that software developers using this workflow can reduce runtime:
- Run on Linux/Mac platform, which is significantly faster by taking advantage of the POSIX fork call.
- Use the
--no-ssl
flag to prevent SSL initialization in OpenStudio. - Use the
-s
flag to skip HPXML validation. - Do not use the
--hourly-output
flag unless hourly output is required. - Run on computing environments with 1) fast CPUs, 2) sufficient memory, and 3) enough processors to allow all simulations to run in parallel.