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: .. table:: Fuel Types and Units =============== ======= Fuel Type Units =============== ======= ``electric`` kWh ``natural gas`` kBtu ``lpg`` kBtu ``fuel_oil`` kBtu ``cord_wood`` kBtu ``pellet_wood`` kBtu =============== ======= .. code:: json { "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). .. code:: json { "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. .. code:: json { "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). .. code:: json { "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: .. jsontable:: resources/site_to_source.json 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. .. code:: json { "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. .. math:: E_{net,src} = \sum_{i, j}^{\text{fuels, end uses}} \left( E_{i,j} s_{i} \right) - E_{pv} s_{elec} .. code:: json { "quantity": 121.5, "period_type": "year", "resource_type": "net_source_energy", "units": "MBtu" } .. _asset-source-energy: 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. .. math:: E_{asset,src} = \sum_{i}^{\text{fuels}} \left( E_{heat} s_{i} + E_{cool} s_{i} + E_{hw} s_{i} \right) - E_{pv} .. code:: json { "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`` .. code:: json { "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 :download:`available to download <../../resources/lu_carbon_factor_by_state.csv>`. .. code:: json { "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. .. table:: 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 =============== ======= ============== ========== =============================== .. code:: json { "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. .. code:: json { "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. .. code:: json { "quantity": 1738.81, "period_type": "year", "resource_type": "utility_bill_cost", "units": "USD" } Score ----- The :ref:`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 :download:`Scoring Bins <../_static/home_energy_score_bins_2025.01.xlsx>` here. The scoring bins are defined for each weather station. To get the score in the table, the :ref:`asset-source-energy` must be less than or equal to the number in the column for that scoring bin. .. code:: json { "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 [#fpa]_ 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 [#roofarea]_ sqft roof2_roof_area [#roofarea]_ sqft roof1_skylight_area sqft roof2_skylight_area sqft front_wall_area [#wallarea]_ sqft back_wall_area [#wallarea]_ sqft left_wall_area [#wallarea]_ sqft right_wall_area [#wallarea]_ sqft front_window_area sqft back_window_area sqft left_window_area sqft right_window_area sqft hvac1_duct1_area [#ductarea]_ sqft hvac1_duct2_area [#ductarea]_ sqft hvac1_duct3_area [#ductarea]_ sqft hvac2_duct1_area [#ductarea]_ sqft hvac2_duct2_area [#ductarea]_ sqft hvac2_duct3_area [#ductarea]_ sqft hvac1_cooling_capacity [#hvaccap]_ Btuh hvac1_heating_capacity [#hvaccap]_ Btuh hvac2_cooling_capacity [#hvaccap]_ Btuh hvac2_heating_capacity [#hvaccap]_ Btuh water_heater_capacity gal ================================== ======= .. [#fpa] Footprint area is the total conditioned floor area, minus any conditioned basement area, divided by the number of floors. .. [#roofarea] 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. .. [#wallarea] 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. .. [#ductarea] Reported duct areas only include ducts are outside conditioned space. .. [#hvaccap] HVAC capacity is calculated via a methodology compatible with ACCA Manual J.