Outputs¶
Upon completion of the ERI calculation, summary output files and simulation files are available. See the sample_results directory for examples of these outputs.
Summary Files¶
Several summary files described below are found in the results
directory.
ERI_Results.csv¶
The ERI_Results.csv
file includes the ERI result as well as the high-level components (e.g., REUL, EC_r, EC_x, IAD_Save) that comprise the ERI calculation.
The file reflects the format of the Results tab of the HERS Method Test spreadsheet.
Note that multiple comma-separated values will be reported for many of these outputs if there are multiple heating, cooling, or hot water systems.
See the example ERI_Results.csv.
ERI_Worksheet.csv¶
The ERI_Worksheet.csv
file includes more detailed components that feed into the ERI_Results.csv values.
The file reflects the formate of the Worksheet tab of the HERS Method Test spreadsheet.
Note that multiple comma-separated values will be reported for many of these outputs if there are multiple heating, cooling, or hot water systems.
See the example ERI_Worksheet.csv.
ERI______Home.csv¶
A CSV file is written for each of the homes simulated (e.g., ERIReferenceHome.csv
for the Reference home).
The CSV file includes multiple sections with different outputs.
1. Annual Energy Consumption by Fuel Type. Current fuel types are: “Electricity”, “Natural Gas”, “Fuel Oil”, “Propane”. It also includes an “Electricity: Net” field that incorporates any renewable generation.
2. Annual Energy Consumption By Fuel Type and End Use. Current fuel types are: “Electricity”, “Natural Gas”, “Fuel Oil”, “Propane”. Current end uses are: “Heating”, “Heating Fans/Pumps”, “Cooling”, “Cooling Fans/Pumps”, “Hot Water”, “Hot Water Recirc Pump”, “Hot Water Solar Thermal Pump”, “Lighting Interior”, “Lighting Garage”, “Lighting Exterior”, “Mech Vent”, “Whole House Fan”, “Refrigerator”, “Dishwasher”, “Clothes Washer”, “Clothes Dryer”, “Range/Oven”, “Ceiling Fan”, “Plug Loads”, “PV” (negative value for generation).
3. Annual Building Loads. Values are reported for heating, cooling, and hot water. Heating and cooling loads include duct losses. Hot water loads are grouped into A) Delivered (i.e., the load associated with hot water delivered), B) Tank Losses, C) Desuperheater, and D) Solar Thermal. The Delivered hot water load includes any contributions from desuperheaters or solar thermal systems.
4. Annual Unmet Building Loads. Values are reported for heating and cooling. These numbers reflect the amount of heating/cooling load that is not met by the HVAC system, indicating the degree to which the HVAC system is undersized. An HVAC system with sufficient capacity to perfectly maintain the thermostat setpoints will report an unmet load of zero.
5. Peak Building Electricity. Values, in Watts, are reported for the summer and winter seasons. The summer season is defined by the hours of the year when the cooling system is operating, and the winter season is defined by the hours of the year when the heating system is operating.
6. Peak Building Loads. Values, in kBtu, are reported for heating and cooling. Heating and cooling peak loads include duct losses.
7. Annual Component Building Loads. Component loads represent the estimated contribution of different building components to the annual heating/cooling building loads. The sum of component loads for heating (or cooling) will roughly equal the annual heating (or cooling) building load reported above. Component loads are currently disaggregated as follows:
Component Definition Roofs Heat transfer through HPXML Roof
elements adjacent to conditioned spaceCeilings Heat transfer through HPXML FrameFloor
elements (inferred to be ceilings) adjacent to conditioned spaceWalls Heat transfer through HPXML Wall
elements adjacent to conditioned spaceRim Joists Heat transfer through HPXML RimJoist
elements adjacent to conditioned spaceFoundation Walls Heat transfer through HPXML FoundationWall
elements adjacent to conditioned spaceDoors Heat transfer through HPXML Door
elements on surfaces adjacent to conditioned spaceWindows Heat transfer through HPXML Window
elements on surfaces adjacent to conditioned space, including direct/diffuse transmitted solarSkylights Heat transfer through HPXML Skylight
elements on surfaces adjacent to conditioned space, including direct/diffuse transmitted solarFloors Heat transfer through HPXML FrameFloor
elements (inferred to be floors) adjacent to conditioned spaceSlabs Heat transfer through HPXML Slab
elements adjacent to conditioned spaceInternal Mass Heat transfer from additional assumed mass (furniture, interior walls, interior floors between stories) in conditioned space Infiltration Airflow induced by stack and wind effects Natural Ventilation Airflow through operable windows Mechanical Ventilation Airflow (and potentially fan heat gain) from a whole house mechanical ventilation system Ducts Conduction and leakage losses through supply/return ducts outside conditioned space Internal Gains Heat gains/losses due to appliances, lighting, plug loads, water heater tank losses, etc. in the conditioned space
See the example ERIRatedHome.csv.
ERI______Home_Hourly.csv¶
If the --hourly
argument is provided when running the workflow, a CSV file of hourly outputs is written for the Reference/Rated Homes (e.g., ERIReferenceHome_Hourly.csv
for the Reference home).
Depending on the hourly output types requested, CSV files may include:
temperatures
: Average space temperatures (in deg-F) for each space modeled (e.g., living space, vented attic, garage, unconditioned basement, crawlspace, etc.).fuels
: Energy use for each fuel type (in kBtu for fossil fuels and kWh for electricity).enduses
: Energy use for each end use type (in kBtu for fossil fuels and kWh for electricity).loads
: Heating and cooling loads (in kBtu) for the building.componentloads
: Heating and cooling loads (in kBtu) disaggregated by component (e.g., Walls, Windows, Infiltration, Ducts, etc.).
See the example ERIRatedHome_Hourly.csv.
ERI______Home.xml¶
A HPXML file is written for each of the homes simulated (e.g., ERIReferenceHome.xml
for the Reference home).
The file reflects the configuration of the home after applying the ERI 301 ruleset.
See the example ERIRatedHome.xml.
Simulation Files¶
In addition, raw EnergyPlus simulation input/output files are available for each simulation (e.g., ERIRatedHome
, ERIReferenceHome
, etc. directories).
Warning
It is highly discouraged for software tools to read the raw EnergyPlus output files. The EnergyPlus input/output files are made available for inspection, but the outputs for certain situations can be misleading if one does not know how the model was created. If there are additional outputs of interest that are not available in our summary output files, please send us a request.
See the example ERIRatedHome directory.