Workflow 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 format 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 the following sections of output.

See the example ERIRatedHome.csv.

Annual Energy Consumption by Fuel Type¶

Current fuel uses are listed below.

Type Notes

Electricity: Total (MBtu)

Electricity: Net (MBtu) Subtracts any power produced by PV or generators.

Natural Gas: Total (MBtu)

Fuel Oil: Total (MBtu)

Propane: Total (MBtu)

Wood Cord: Total (MBtu)

Wood Pellets: Total (MBtu)

Annual Energy Consumption By End Use¶

Current end uses are listed below.

Note that all end uses are mutually exclusive – the “Electricity: Heating” end use, for example, excludes energy reported in the “Electricity: Heating Fans/Pumps” end use. So the sum of all end uses for a given fuel (e.g., sum of all “End Use: Natural Gas: *”) equal the above reported fuel use (e.g., “Fuel Use: Natural Gas: Total”).

Type Notes

Electricity: Heating (MBtu) Excludes fans/pumps

Electricity: Heating Fans/Pumps (MBtu)

Electricity: Cooling (MBtu) Excludes fans/pumps

Electricity: Cooling Fans/Pumps (MBtu)

Electricity: Hot Water (MBtu) Excludes recirc pump and solar thermal pump

Electricity: Hot Water Recirc Pump (MBtu)

Electricity: Hot Water Solar Thermal Pump (MBtu)

Electricity: Lighting Interior (MBtu)

Electricity: Lighting Garage (MBtu)

Electricity: Lighting Exterior (MBtu)

Electricity: Mech Vent (MBtu) Excludes preheating/precooling

Electricity: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Electricity: Mech Vent Precooling (MBtu) Shared ventilation preconditioning system

Electricity: Whole House Fan (MBtu)

Electricity: Refrigerator (MBtu)

Electricity: Dehumidifier (MBtu)

Electricity: Dishwasher (MBtu)

Electricity: Clothes Washer (MBtu)

Electricity: Clothes Dryer (MBtu)

Electricity: Range/Oven (MBtu)

Electricity: Ceiling Fan (MBtu)

Electricity: Television (MBtu)

Electricity: Plug Loads (MBtu) Excludes independently reported plug loads (e.g., well pump)

Electricity: PV (MBtu) Negative value for any power produced

Electricity: Generator (MBtu) Negative value for any power produced

Natural Gas: Heating (MBtu)

Natural Gas: Hot Water (MBtu)

Natural Gas: Clothes Dryer (MBtu)

Natural Gas: Range/Oven (MBtu)

Natural Gas: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Natural Gas: Generator (MBtu) Positive value for any fuel consumed

Fuel Oil: Heating (MBtu)

Fuel Oil: Hot Water (MBtu)

Fuel Oil: Clothes Dryer (MBtu)

Fuel Oil: Range/Oven (MBtu)

Fuel Oil: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Propane: Heating (MBtu)

Propane: Hot Water (MBtu)

Propane: Clothes Dryer (MBtu)

Propane: Range/Oven (MBtu)

Propane: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Propane: Generator (MBtu) Positive value for any fuel consumed

Wood Cord: Heating (MBtu)

Wood Cord: Hot Water (MBtu)

Wood Cord: Clothes Dryer (MBtu)

Wood Cord: Range/Oven (MBtu)

Wood Cord: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Wood Pellets: Heating (MBtu)

Wood Pellets: Hot Water (MBtu)

Wood Pellets: Clothes Dryer (MBtu)

Wood Pellets: Range/Oven (MBtu)

Wood Pellets: Mech Vent Preheating (MBtu) Shared ventilation preconditioning system

Annual Building Loads¶

Current annual building loads are listed below.

Type Notes

Load: Heating (MBtu) Includes HVAC distribution losses.

Load: Cooling (MBtu) Includes HVAC distribution losses.

Load: Hot Water: Delivered (MBtu) Includes contributions by desuperheaters or solar thermal systems.

Load: Hot Water: Tank Losses (MBtu)

Load: Hot Water: Desuperheater (MBtu) Load served by the desuperheater.

Load: Hot Water: Solar Thermal (MBtu) Load served by the solar thermal system.

Annual Unmet Building Loads¶

Current annual unmet building loads are listed below.

Type Notes

Unmet Load: Heating (MBtu)

Unmet Load: Cooling (MBtu)

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.

Peak Building Electricity¶

Current peak building electricity outputs are listed below.

Type Notes

Peak Electricity: Winter Total (W) Winter season defined by operation of the heating system.

Peak Electricity: Summer Total (W) Summer season defined by operation of the cooling system.

Peak Building Loads¶

Current peak building loads are listed below.

Type Notes

Peak Load: Heating (kBtu) Includes HVAC distribution losses.

Peak Load: Cooling (kBtu) Includes HVAC distribution losses.

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. Current component loads disaggregated by Heating/Cooling are listed below.

Type Notes

Component Load: *: Roofs (MBtu) Heat gain/loss through HPXML Roof elements adjacent to conditioned space

Component Load: *: Ceilings (MBtu) Heat gain/loss through HPXML FrameFloor elements (inferred to be ceilings) adjacent to conditioned space

Component Load: *: Walls (MBtu) Heat gain/loss through HPXML Wall elements adjacent to conditioned space

Component Load: *: Rim Joists (MBtu) Heat gain/loss through HPXML RimJoist elements adjacent to conditioned space

Component Load: *: Foundation Walls (MBtu) Heat gain/loss through HPXML FoundationWall elements adjacent to conditioned space

Component Load: *: Doors (MBtu) Heat gain/loss through HPXML Door elements adjacent to conditioned space

Component Load: *: Windows (MBtu) Heat gain/loss through HPXML Window elements adjacent to conditioned space, including solar

Component Load: *: Skylights (MBtu) Heat gain/loss through HPXML Skylight elements adjacent to conditioned space, including solar

Component Load: *: Floors (MBtu) Heat gain/loss through HPXML FrameFloor elements (inferred to be floors) adjacent to conditioned space

Component Load: *: Slabs (MBtu) Heat gain/loss through HPXML Slab elements adjacent to conditioned space

Component Load: *: Internal Mass (MBtu) Heat gain/loss from internal mass (e.g., furniture, interior walls/floors) in conditioned space

Component Load: *: Infiltration (MBtu) Heat gain/loss from airflow induced by stack and wind effects

Component Load: *: Natural Ventilation (MBtu) Heat gain/loss from airflow through operable windows

Component Load: *: Mechanical Ventilation (MBtu) Heat gain/loss from airflow/fan energy from a whole house mechanical ventilation system

Component Load: *: Whole House Fan (MBtu) Heat gain/loss from airflow due to a whole house fan

Component Load: *: Ducts (MBtu) Heat gain/loss from conduction and leakage losses through supply/return ducts outside conditioned space

Component Load: *: Internal Gains (MBtu) Heat gain/loss from appliances, lighting, plug loads, water heater tank losses, etc. in the conditioned space

Annual Hot Water Uses¶

Current annual hot water uses are listed below.

Type Notes

Hot Water: Clothes Washer (gal)

Hot Water: Dishwasher (gal)

Hot Water: Fixtures (gal) Showers and faucets.

Hot Water: Distribution Waste (gal)

ERI______Home_Hourly.csv¶

See the Running section for requesting hourly outputs. When requested, 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 outputs requested, CSV files may include:

Type Notes

Fuel Consumptions Energy use for each fuel type (in kBtu for fossil fuels and kWh for electricity).

End Use Consumptions Energy use for each end use type (in kBtu for fossil fuels and kWh for electricity).

Hot Water Uses Water use for each end use type (in gallons).

Total Loads Heating, cooling, and hot water loads (in kBtu) for the building.

Component Loads Heating and cooling loads (in kBtu) disaggregated by component (e.g., Walls, Windows, Infiltration, Ducts, etc.).

Unmet Loads Unmet heating and cooling loads (in kBtu) for the building.

Zone Temperatures Average temperatures (in deg-F) for each space modeled (e.g., living space, attic, garage, basement, crawlspace, etc.).

Airflows Airflow rates (in cfm) for infiltration, mechanical ventilation, natural ventilation, and whole house fans.

Weather Weather file data including outdoor temperatures, relative humidity, wind speed, and solar.

Timestamps in the output use the end-of-hour convention. Most outputs will be summed over the hour (e.g., energy) but some will be averaged over the hour (e.g., temperatures, airflows).

See the example ERIRatedHome_Hourly.csv.

ERI______Home.xml¶

An 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.

The file will also show HPXML default values that are applied as part of modeling this home. Defaults will be applied for a few different reasons:

Optional ERI inputs aren’t provided (e.g., ventilation rate for a vented attic, SHR for an air conditioner, etc.)
Modeling assumptions (e.g., 1 hour timestep, Jan 1 - Dec 31 run period, appliance schedules, etc.)
HVAC sizing calculations (e.g., autosized HVAC capacities and airflow rates, heating/cooling design loads)

Any HPXML-defaulted values will include the dataSource='software' attribute.

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.