Outputs

End Uses

Each of the following end uses are reported by fuel type:

• heating: Space heating primary energy use, fans, pumps, and backup heating

• cooling: Space cooling primary energy use and fans

• hot_water: Water heating energy use

• large_appliance: Refrigerators, dishwashers, clothes washers, clothes dryers

• small_appliance: Range/oven, televisions, plug loads

• lighting: Interior and exterior

• generation: PV generation. Reported as positive values.

For each end use by fuel type the results are reported in the following units:

Fuel Types and Units

Fuel Type	Units
electric	kWh
natural gas	kBtu
lpg	kBtu
fuel_oil	kBtu
cord_wood	kBtu
pellet_wood	kBtu

{
  "quantity": 442.54,
  "period_type": "year",
  "end_use": "heating",
  "resource_type": "electric",
  "units": "kWh"
}

Hot Water

Hot water use is reported in gallons. All values are gallons of hot water (e.g., at water heater setpoint), not total water (e.g., at the fixture temperature).

{
  "quantity": 21572.2,
  "period_type": "year",
  "end_use": "hot_water",
  "resource_type": "hot_water",
  "units": "gal"
}

Site Energy

Total Site Energy

Total site energy is calculated by summing all the end uses and converting to million Btu (MBtu). Generation is excluded from the total site energy.

{
  "quantity": 111.63,
  "period_type": "year",
  "resource_type": "total_site_energy",
  "units": "MBtu"
}

Net Site Energy

Net site energy is calculated by subtracting the generation from the total site energy and is reported in million Btu (MBtu).

{
  "quantity": 94.9,
  "period_type": "year",
  "resource_type": "net_site_energy",
  "units": "MBtu"
}

Source Energy

Source energy is calculated by converting all fuel types to million Btu and multiplying by the site-to-source factors below:

Fuel Type	Conversion Factor
Electric	2.44
Natural Gas	1.05
Lpg	1.01
Fuel Oil	1.01
Cord Wood	1.0
Pellet Wood	1.0

Total Source Energy

Total source energy is calculated by summing all the fuel use multiplied by their respective site-to-source factors. It excludes generation.

{
  "quantity": 162.33,
  "period_type": "year",
  "resource_type": "total_source_energy",
  "units": "MBtu"
}

Net Source Energy

Net source energy is calculated by subtracting the generation from the total source energy. Generation is multiplied by the electricity site-to-source factor.

\[E_{net,src} = \sum_{i, j}^{\text{fuels, end uses}} \left( E_{i,j} s_{i} \right) - E_{pv} s_{elec}\]

{
  "quantity": 121.5,
  "period_type": "year",
  "resource_type": "net_source_energy",
  "units": "MBtu"
}

Asset Source Energy

Asset source energy is calculated by calculating the source energy of the asset end uses (heating, cooling, and hot water) and subtracting the generation (PV). Generation is not multiplied by a site-to-source factor.

\[E_{asset,src} = \sum_{i}^{\text{fuels}} \left( E_{heat} s_{i} + E_{cool} s_{i} + E_{hw} s_{i} \right) - E_{pv}\]

{
  "quantity": 87.08,
  "period_type": "year",
  "resource_type": "asset_source_energy",
  "units": "MBtu"
}

Energy Use Intensity

The site and source energy outputs are also available as an energy use intensity (EUI), which are calculated by dividing each of those outputs by the conditioned floor area and converting to kBtu/sqft. The following EUI outputs are available:

• total_site_energy_eui

• net_site_energy_eui

• total_source_energy_eui

• net_source_energy_eui

• asset_source_energy_eui

{
  "quantity": 55.82,
  "period_type": "year",
  "resource_type": "total_site_energy_eui",
  "units": "kBtu/sqft"
},
{
  "quantity": 47.45,
  "period_type": "year",
  "resource_type": "net_site_energy_eui",
  "units": "kBtu/sqft"
},
{
  "quantity": 81.17,
  "period_type": "year",
  "resource_type": "total_source_energy_eui",
  "units": "kBtu/sqft"
},
{
  "quantity": 60.75,
  "period_type": "year",
  "resource_type": "net_source_energy_eui",
  "units": "kBtu/sqft"
},
{
  "quantity": 43.54,
  "period_type": "year",
  "resource_type": "asset_source_energy_eui",
  "units": "kBtu/sqft"
}

Carbon Emissions

Carbon emissions are calculated using EPA eGrid state average carbon factors for electricity and nationwide averages for other fuels. A table of the carbon factors used is available to download.

{
  "quantity": 16089,
  "period_type": "year",
  "resource_type": "carbon_emissions",
  "units": "lb"
}

Utility Use

The total by each fuel used is reported in units that are typical for each fuel.

Utility use fuel units

Fuel Type	Units	Original Units	Multiplier	Notes
electric	kWh	kWh	1	Including PV generation
natural gas	therms	kBtu	1/100
lpg	gal	kBtu	1/91.6
fuel_oil	gal	kBtu	1/139
cord_wood	cord	kBtu	1/20,000	20 MBtu/cord
pellet_wood	lb	kBtu	2/16.4	16.4 MBtu/ton and 2000 lb/ton

{
  "quantity": 9513.09,
  "period_type": "year",
  "resource_type": "utility_use_electric",
  "units": "kWh"
},
{
  "quantity": 791.7,
  "period_type": "year",
  "resource_type": "utility_use_natural_gas",
  "units": "therm"
},
{
  "quantity": 0.0,
  "period_type": "year",
  "resource_type": "utility_use_lpg",
  "units": "gal"
},
{
  "quantity": 0.0,
  "period_type": "year",
  "resource_type": "utility_use_fuel_oil",
  "units": "gal"
},
{
  "quantity": 0.0,
  "period_type": "year",
  "resource_type": "utility_use_cord_wood",
  "units": "cord"
},
{
  "quantity": 0.0,
  "period_type": "year",
  "resource_type": "utility_use_pellet_wood",
  "units": "lb"
}

Utility Cost

Utility costs are calculated using state average utility rates, including fixed and marginal charges. The fixed charge and marginal rates used in the calculation are reported.

{
  "quantity": 12.0,
  "period_type": "year",
  "resource_type": "utility_bill_fixed_charge_electric",
  "units": "USD/month"
},
{
  "quantity": 0.1065,
  "period_type": "year",
  "resource_type": "utility_bill_marginal_rate_electric",
  "units": "USD/kWh"
},
{
  "quantity": 12.0,
  "period_type": "year",
  "resource_type": "utility_bill_fixed_charge_natural_gas",
  "units": "USD/month"
},
{
  "quantity": 1.2125,
  "period_type": "year",
  "resource_type": "utility_bill_marginal_rate_natural_gas",
  "units": "USD/therm"
},

The applicable fixed and marginal utility rates are applied and summed to calculate a total utility cost.

{
  "quantity": 1738.81,
  "period_type": "year",
  "resource_type": "utility_bill_cost",
  "units": "USD"
}

Score

The Asset Source Energy is used to determine the Score by looking up in the scoring bins. There are separate sets of bins for single-family and multi-family buildings. The score is reported as an integer between 1-10.

You can download the Scoring Bins here.

The scoring bins are defined for each weather station. To get the score in the table, the Asset Source Energy must be less than or equal to the number in the column for that scoring bin.

{
  "quantity": 5,
  "resource_type": "score"
}

Cost Multipliers

Several quantities are used to calculate upgrade costs such as surface areas to be insulated. These quantities are reported with the following units:

Cost Multiplier	Units
footprint_area [1]	sqft
conditioned_floor_area	sqft
floor1_floor_area	sqft
floor2_floor_area	sqft
floor1_wall_area	sqft
floor2_wall_area	sqft
roof1_ceiling_area	sqft
roof2_ceiling_area	sqft
roof1_kneewall_area	sqft
roof2_kneewall_area	sqft
roof1_roof_area [2]	sqft
roof2_roof_area [2]	sqft
roof1_skylight_area	sqft
roof2_skylight_area	sqft
front_wall_area [3]	sqft
back_wall_area [3]	sqft
left_wall_area [3]	sqft
right_wall_area [3]	sqft
front_window_area	sqft
back_window_area	sqft
left_window_area	sqft
right_window_area	sqft
hvac1_duct1_area [4]	sqft
hvac1_duct2_area [4]	sqft
hvac1_duct3_area [4]	sqft
hvac2_duct1_area [4]	sqft
hvac2_duct2_area [4]	sqft
hvac2_duct3_area [4]	sqft
hvac1_cooling_capacity [5]	Btuh
hvac1_heating_capacity [5]	Btuh
hvac2_cooling_capacity [5]	Btuh
hvac2_heating_capacity [5]	Btuh
water_heater_capacity	gal

[1]

Footprint area is the total conditioned floor area, minus any conditioned basement area, divided by the number of floors.

[2] (1,2)

Roof area is the total roof area. For attics where the user enters a ceiling area it is calculated by assuming a 30 degree roof angle with a gable roof. Skylight area is subtracted from the roof area.

[3] (1,2,3,4)

Wall area is determined by assuming a 5:3 ratio for the footprint with the long side facing front for a single-family detached, the short side facing the front for a single-family detached, a square footprint for multi-family units, and a longer rectangle ratio for manufactured homes based on the sections. Wall height is assumed to be 8 ft/floor. Window area is subtracted from wall area.

[4] (1,2,3,4,5,6)

Reported duct areas only include ducts are outside conditioned space.

[5] (1,2,3,4)

HVAC capacity is calculated via a methodology compatible with ACCA Manual J.