The energy use data embedded in the Building Decarbonization Calculator is modeled with the physics-based EnergyPlus whole building energy simulation engine supplemented by a machine learning algorithm. Simulations were performed using the Existing Commercial Reference Buildings Constructed In or After 1980 (v1.4) provided by the United States Department of Energy. Simulations were performed for every possible combination of ECCMs available in the Building Decarbonization Calculator within each Building Segment, across all representative climate zones.
Results of these simulations were normalized by unit gross floor area. When asset data is entered in Calculator, the area-normalized data is scaled to the user input.
In the context of energy consumption, "end use" refers to the specific category or application where energy is utilized within a building or system. End use breaks down total energy use into individual functions, such as heating, cooling, lighting, or equipment operation. Understanding end uses helps identify where energy is consumed most and informs targeted energy efficiency measures for each category.
The following is a summary of the characteristics of the prototype models used in the analysis. Full model documentation and the models themselves are available from the US Department of Energy Office of Energy Efficiency and Renewable Energy.
| Use Category | Conditioned GFA | Window-to-Wall Ratio |
|---|---|---|
| Hospital (built before 2000) | 564,400 sf | 16% |
| Hospital (built after 2000) | 241,410 sf | 16% |
| Hotel (small) | 43,200 sf | 11% |
| Hotel (large) | 122,132 sf | 30% |
| Office (small) | 5,500 sf | 21% |
| Office (medium) | 53,600 sf | 33% |
| Office (large) | 498,600 sf | 40% |
| Supermarket | 45,006 sf | 7% |
| Urban Grocery* | 5,000 sf | 15% |
** The urban grocery prototype model was created for this tool only and is not a DoE-supplied model.*
| Use Category | Baseline HVAC Systems |
|---|---|
| Hospital | Hot water system with gas boilers; Chilled water system with water-cooled chillers and open cooling tower; Floor-by-floor VAV AHUs with hot water reheat and steam humidifiers; Central service water heaters - gas-fired |
| Hotel (small) | Packages terminal air conditioner with electric heating; Packaged rooftop air conditioner or Packaged rooftop air conditioner with two fan speed (Size dependent); Warm air furnace, electric |
| Hotel (large) | Hot water system with gas boilers; Chilled water system with air-cooled chillers; Guest rooms: four-pipe fan coils; Public spaces: VAV with hot water reheat; Central service water heaters - gas-fired |
| Office (small) | Packaged rooftop heat pump with gas auxiliary heat |
| Office (medium) | Packaged air conditioning unit with gas-fired heating; Distribution via Variable Air Volume (VAV) terminals with electric reheat; Service water heaters - gas-fired |
| Office (large) | Hot water system with a gas boiler; Chilled water system with water-cooled chillers and open cooling tower; Fluid coolers for data centers; Distribution via VAV terminals with hot water reheat; Service water heaters - gas-fired |
| Supermarket | Packaged single-zone rooftop units with DX cooling and gas-fired furnaces; Service water heaters - gas-fired |
| Use Category | Baseline HVAC Systems |
|---|---|
| Hospital | Fan coil units with gas boilers and water-cooled chillers; Dedicated Outside Air System (DOAS) with hydronic heating and cooling coils |
| Hotel (small) | Packages terminal air conditioner with electric heating; Packaged rooftop air conditioner or Packaged rooftop air conditioner with two fan speed (Size dependent); Warm air furnace, electric |
| Hotel (large) | Hot water system with gas boilers; Chilled water system with air-cooled chillers; Guest rooms: four-pipe fan coils; Public spaces: VAV with hot water reheat; Central service water heaters - gas-fired |
| Office (small) | Packaged rooftop heat pump with gas auxiliary heat |
| Office (medium | Packaged air conditioning unit with gas-fired heating; Distribution via Variable Air Volume (VAV) terminals with electric reheat; Service water heaters - gas-fired |
| Office (large) | Hot water system with a gas boiler; Chilled water system with water-cooled chillers and open cooling tower; Fluid coolers for data centers; Distribution via VAV terminals with hot water reheat; Service water heaters - gas-fired |
| Supermarket | Packaged single-zone rooftop units with DX cooling and gas-fired furnaces; Service water heaters - gas-fired; Air-to-air heat recovery in all Northern European locations |
| Use Category | Baseline HVAC Systems |
|---|---|
| Hospital | Fan coil units with hydronic coils served by water-cooled chillers; Dedicated Outside Air System (DOAS) with hydronic heating and cooling coils; Demand Control Ventilation was assumed when built after 2000; No airside heat/energy recovery |
| Hotel (small) | Packages terminal air conditioner with electric heating; Packaged rooftop air conditioner or Packaged rooftop air conditioner with two fan speed (Size dependent); Warm air furnace, electric; No airside heat/energy recovery |
| Hotel (large) | Hot water system with gas boilers; Chilled water system with air-cooled chillers; Guest rooms: four-pipe fan coils; Public spaces: VAV with hot water reheat; Central service water heaters - gas-fired; No airside heat/energy recovery |
| Office (small) | Packaged rooftop heat pump with gas auxiliary heat |
| Office (medium) | Packaged air conditioning unit with gas-fired heating; Distribution via Variable Air Volume (VAV) terminals with electric reheat; Service water heaters - gas-fired; No Demand Control Ventilation when built after 2000 |
| Office (large) | Hot water system with a gas boiler; Chilled water system with water-cooled chillers and open cooling tower; Fluid coolers for data centers; Distribution via VAV terminals with hot water reheat; Service water heaters - gas-fired; No Demand Control Ventilation when built after 2000; Energy recovery wheels on all air handling units |
| Supermarket | Packaged single-zone rooftop units with DX cooling and gas-fired furnaces; Service water heaters - gas-fired |
| Use Category | Baseline HVAC Systems |
|---|---|
| Hospital | Hot water system with gas boilers; Air-cooled chillers when built before 2000, and district cooling system when built after 2000; Floor-by-floor VAV AHUs with hot water reheat and steam humidifiers; Central service water heaters - gas-fired; No energy recovery |
| Hotel (small) | Packages terminal air conditioner with electric heating; Packaged rooftop air conditioner or Packaged rooftop air conditioner with two fan speed (Size dependent); Warm air furnace, electric; No energy recovery |
| Hotel (large) | Hot water system with gas boilers; Chilled water system with air-cooled chillers; Guest rooms: four-pipe fan coils; Public spaces: VAV with hot water reheat; Central service water heaters - gas-fired; No energy recovery |
| Office (small) | Packaged rooftop heat pump with gas auxiliary heat; No energy recovery |
| Office (medium) | Packaged air conditioning unit with gas-fired heating; Distribution via Variable Air Volume (VAV) terminals with electric reheat; Service water heaters - gas-fired |
| Office (large) | Hot water system with a gas boiler; water-cooled chillers when built before 2000, and air-cooled chillers when built after 2000; Fluid coolers for data centers; Single-zone packaged split air conditioners when built before 2000, and distribution via Variable Air Volume (VAV) terminals with electric reheat when built after 2000; Service water heaters - gas-fired; No energy recovery |
| Supermarket | Packaged single-zone rooftop units with DX cooling and gas-fired furnaces; Service water heaters - gas-fired; No energy recovery |
| Use Category | Baseline HVAC Systems |
|---|---|
| Hospital | Hot water system with gas boilers; Chilled water system with air-cooled chillers and open cooling tower; Floor-by-floor VAV AHUs with hot water reheat and steam humidifiers; Central service water heaters - gas-fired; No energy recovery |
| Hotel (small) | Packages terminal air conditioner with electric heating; Packaged rooftop air conditioner or Packaged rooftop air conditioner with two fan speed (Size dependent); Warm air furnace, electric; No energy recovery |
| Hotel (large) | Hot water system with gas boilers; Chilled water system with air-cooled chillers; Guest rooms: four-pipe fan coils; Public spaces: VAV with hot water reheat; Central service water heaters - gas-fired; No energy recovery |
| Office (small) | Packaged rooftop heat pump with gas auxiliary heat; No energy recovery |
| Office (medium) | Packaged air conditioning unit with gas-fired heating; Distribution via Variable Air Volume (VAV) terminals with electric reheat; Service water heaters - gas-fired; No energy recovery |
| Office (large) | Hot water system with a gas boiler; water-cooled chillers when built before 2000, and air-cooled chillers when built after 2000; Fluid coolers for data centers; Single-zone packaged split air conditioners when built before 2000, and distribution via Variable Air Volume (VAV) terminals with electric reheat when built after 2000; Service water heaters - gas-fired; No energy recovery |
| Supermarket | Packaged single-zone rooftop units with DX cooling and gas-fired furnaces; Service water heaters - gas-fired; No energy recovery |
To fill in the location-specific climate data required for analysis, the Building Decarbonization Calculator pairs a user's selected location with a representative location that is complete with ASHRAE climate zone data. Matching between selected and representative locations is completed using the following order of operations:
The following is the list of the representative cities for each ASHRAE Climate Zone modeled in the Building Decarbonization Calculator. More data on the ASHRAE Climate Zones is available online (pdf).
Australia
Canada
USA