Refinement of Building Details
One of the main methods to make any Glimpse calculation more accurate is to refine the building details, that is, give the software anything known about the building’s equipment, envelope, and operations.
User Interface
Methods for users to access refinement are the Tier 2 API and the Tier 2 Input Form in the Glimpse Platform.
Standardized Internal Definition
The refinement input methods serve different uses, so they have different input possibilities. For example, The API allows the specification of an unlimited amount of HVAC systems, while the Platform only allows two - a primary and a secondary. Regardless of the input method or the schema that limits the input options, the user’s inputs are processed into a standardized internal definition of a building’s energy using processes.
Building → HVAC
| Description | System Path |
|---|---|
| Type of plant heating source | Building → HVAC → Waterside Systems |
| Type of plant cooling source | Building → HVAC → Waterside Systems |
| Pump power normalized by flow, serving as an efficacy metric (W/gpm) | Building → HVAC → Waterside Systems |
|
Fuel type used by the chiller
|
Building → HVAC → Waterside Systems |
| Chiller coefficient of performance (COP) | Building → HVAC → Waterside Systems |
|
Fuel type used by the boiler
|
Building → HVAC → Waterside Systems |
| Boiler thermal efficiency (numeric 0–1) | Building → HVAC → Waterside Systems |
| Heating COP of plant heat pump (COP) | Building → HVAC → Waterside Systems |
| Cooling COP of plant heat pump (COP) | Building → HVAC → Waterside Systems |
| Total condenser fan motor size (hp) | Building → HVAC → Waterside Systems |
| Whether plant pumps have variable speed control | Building → HVAC → Waterside Systems |
| Fraction of building load served by this plant (0–1) | Building → HVAC → Waterside Systems |
| Heating hot water supply temperature (°C) | Building → HVAC → Waterside Systems |
| Type of zone heating equipment served by plant | Building → HVAC → Waterside Systems |
| Type of zone cooling equipment served by plant | Building → HVAC → Waterside Systems |
| Pump efficiency (0–1) | Building → HVAC → Waterside Systems |
| Whether condenser fans have variable speed control | Building → HVAC → Waterside Systems |
| Hot water supply temperature setpoint (°C) | Building → HVAC → Waterside Systems |
| Hot water return temperature (°C) | Building → HVAC → Waterside Systems |
| Chilled water supply temperature (°C) | Building → HVAC → Waterside Systems |
| Chilled water return temperature (°C) | Building → HVAC → Waterside Systems |
| Condenser water supply temperature (°C) | Building → HVAC → Waterside Systems |
| Condenser water return temperature (°C) | Building → HVAC → Waterside Systems |
| Boiler performance curve definitions | Building → HVAC → Waterside Systems |
| Air-cooled chiller performance curves | Building → HVAC → Waterside Systems |
| Water-cooled chiller performance curves | Building → HVAC → Waterside Systems |
| Heat pump performance curve definitions | Building → HVAC → Waterside Systems |
| Whether hot water reset control is enabled | Building → HVAC → Waterside Systems |
| Hot water reset control information | Building → HVAC → Waterside Systems |
| Whether plant operates as two-pipe system | Building → HVAC → Waterside Systems |
| Whether outdoor air flow varies with occupancy | Building → HVAC → Waterside Systems |
| Air system archetype | Building → HVAC → Airside Systems |
| Cooling source used by air system | Building → HVAC → Airside Systems |
| Cooling efficiency of air system (COP) | Building → HVAC → Airside Systems |
| Heating source used by air system | Building → HVAC → Airside Systems |
|
Furnace fuel type
|
Building → HVAC → Airside Systems |
| Furnace efficiency (0–1) | Building → HVAC → Airside Systems |
| Heat pump heating COP (COP) | Building → HVAC → Airside Systems |
| Single-zone or multi-zone air distribution | Building → HVAC → Airside Systems |
| Terminal unit type | Building → HVAC → Airside Systems |
| Terminal unit reheat energy source | Building → HVAC → Airside Systems |
| Total fan motor power (hp) | Building → HVAC → Airside Systems |
| Fan efficiency (0–1) | Building → HVAC → Airside Systems |
| Whether economizer is present | Building → HVAC → Airside Systems |
| Whether heat recovery is present | Building → HVAC → Airside Systems |
| Whether fans are variable speed | Building → HVAC → Airside Systems |
| Total fan airflow (CFM) | Building → HVAC → Airside Systems |
| Fraction of building served by this air system (fraction 0–1) | Building → HVAC → Airside Systems |
| Fan design external static pressure | Building → HVAC → Airside Systems |
| Whether outdoor air is supplied by the system | Building → HVAC → Airside Systems |
| Configuration of heat recovery system, if existing | Building → HVAC → Airside Systems |
| Hour HVAC system begins operation (0–24) | Building → HVAC → Airside Systems |
| Hour HVAC system stops operation (0–24) | Building → HVAC → Airside Systems |
| Minimum outdoor air fraction | Building → HVAC → Airside Systems |
| Design supply air temperature cooling setpoint (°C) | Building → HVAC → Airside Systems |
| Design supply air temperature heating setpoint (°C) | Building → HVAC → Airside Systems |
| Design preheat supply air temperature setpoint (°C) | Building → HVAC → Airside Systems |
| Minimum air system flow fraction (unitless 0–1) | Building → HVAC → Airside Systems |
| Terminal unit minimum airflow fraction (unitless 0–1) | Building → HVAC → Airside Systems |
| Whether humidification is present at the system level | Building → HVAC → Airside Systems |
| Design minimum outdoor air fraction | Building → HVAC → Airside Systems |
| Whether unit is allowed to run outside normal hours | Building → HVAC → Airside Systems |
| Fan motor efficiency (unitless 0–1) | Building → HVAC → Airside Systems |
| Cooling coil performance curves | Building → HVAC → Airside Systems |
| Heating coil performance curves | Building → HVAC → Airside Systems |
| Fan performance curves | Building → HVAC → Airside Systems |
| Whether supply air temperature reset is enabled | Building → HVAC → Airside Systems |
| Whether fans cycle with load | Building → HVAC → Airside Systems |
| Economizer configuration settings | Building → HVAC → Airside Systems |
| Whether the system operates as a dedicated outdoor air system | Building → HVAC → Airside Systems |
| Parameters controlling supply air temperature reset | Building → HVAC → Airside Systems |
| Static pressure management type | Building → HVAC → Airside Systems |
| Schedule controlling supply air temperature cooling setpoint | Building → HVAC → Airside Systems |
| Demand-controlled ventilation enabled | Building → HVAC → Airside Systems |
| Heat pump performance curves | Building → HVAC → Airside Systems |
| Auxiliary heat pump fuel type | Building → HVAC → Airside Systems |
| Outdoor temperature at which auxiliary heat engages (°C) | Building → HVAC → Airside Systems |
| Packaged system type | Building → HVAC → Standalone Zone Systems |
| Cooling COP of unit (COP) | Building → HVAC → Standalone Zone Systems |
| Heating COP if heat pump (COP) | Building → HVAC → Standalone Zone Systems |
|
Fuel type used by system heating element
|
Building → HVAC → Standalone Zone Systems |
| System heating element efficiency (0–1) | Building → HVAC → Standalone Zone Systems |
| Fan external static pressure (Pa) | Building → HVAC → Standalone Zone Systems |
| Fan efficiency (0–1) | Building → HVAC → Standalone Zone Systems |
| Fan motor efficiency (0–1) | Building → HVAC → Standalone Zone Systems |
| Whether the unit has an economizing function | Building → HVAC → Standalone Zone Systems |
| Whether the unit has a heat recovery module | Building → HVAC → Standalone Zone Systems |
| Supply air temperature setpoint (°C) | Building → HVAC → Standalone Zone Systems |
| Performance curve definitions | Building → HVAC → Standalone Zone Systems |
| Type of zone heater (electric baseboard, gas unit heater) | Building → HVAC → Standalone Zone Heaters |
|
Fuel used by heater
|
Building → HVAC → Standalone Zone Heaters |
| Heater efficiency (0–1) | Building → HVAC → Standalone Zone Heaters |
| Heating capacity (W) | Building → HVAC → Standalone Zone Heaters |
| Fan efficiency if fan-powered heater (0–1) | Building → HVAC → Standalone Zone Heaters |
| Fan motor efficiency (0–1) | Building → HVAC → Standalone Zone Heaters |
| Fan external static pressure rise (Pa) | Building → HVAC → Standalone Zone Heaters |
| Cooling coefficient of performance (COP) | Building → HVAC → Central Refrigerant Systems |
| Heating coefficient of performance (COP) | Building → HVAC → Central Refrigerant Systems |
| Minimum outdoor temperature for heat pump heating operation (°C) | Building → HVAC → Central Refrigerant Systems |
| Maximum outdoor temperature for heating operation (°C) | Building → HVAC → Central Refrigerant Systems |
| Minimum outdoor temperature for cooling operation (°C) | Building → HVAC → Central Refrigerant Systems |
| Maximum outdoor temperature for cooling operation (°C) | Building → HVAC → Central Refrigerant Systems |
| Indoor fan efficiency (0–1) | Building → HVAC → Central Refrigerant Systems |
| Indoor fan motor efficiency (0–1) | Building → HVAC → Central Refrigerant Systems |
| Indoor fan external static pressure (Pa) | Building → HVAC → Central Refrigerant Systems |
| Whether VRF has heat recovery functionality | Building → HVAC → Central Refrigerant Systems |
| VRF performance curves | Building → HVAC → Central Refrigerant Systems |
Building → Domestic Hot Water (DHW)
| Description | System Path |
|---|---|
|
Fuel type used for domestic hot water heating
|
Building → DHW |
| Type of DHW storage tank | Building → DHW |
| Water heater efficiency (0–1) | Building → DHW |
| Storage tank volume (m³) | Building → DHW |
| Tank insulation R-value (hr·ft²·°F/Btu) | Building → DHW |
| Tank standby heat loss parameters | Building → DHW |
| DHW supply temperature setpoint (°C) | Building → DHW |
| DHW return temperature (°C) | Building → DHW |
| Pump design external static pressure (Pa) | Building → DHW |
| Pump efficiency (0–1) | Building → DHW |
| Whether DHW pumps are variable speed | Building → DHW |
Building → Envelope & Materials
| Description | System Path |
|---|---|
| Construction used for interior walls (Construction) | Building → Envelope |
| Construction used for exterior walls (Construction) | Building → Envelope |
| Construction used for ground-contact walls (Construction) | Building → Envelope |
| Construction used for interior ceilings (Construction) | Building → Envelope |
| Construction used for exterior roofs (Construction) | Building → Envelope |
| Construction used for interior floors (Construction) | Building → Envelope |
| Construction used for exposed floors (Construction) | Building → Envelope |
| Construction used for ground-contact floors (Construction) | Building → Envelope |
| Construction for ceilings adjacent to unconditioned spaces | Building → Envelope |
| Construction for walls adjacent to unconditioned spaces | Building → Envelope |
| Construction for floors adjacent to unconditioned spaces | Building → Envelope |
| West-facing window construction (Construction) | Building → Envelope |
| East-facing window construction (Construction) | Building → Envelope |
| South-facing window construction (Construction) | Building → Envelope |
| North-facing window construction (Construction) | Building → Envelope |
| Skylight construction (Construction) | Building → Envelope |
| Opaque door construction (Construction) | Building → Envelope |
| Glazed door construction (Construction) | Building → Envelope |
| Materials forming construction layers, ordered from outside to inside | Building → Envelope → Construction Assembly |
| Type of window shading device, if applicable | Building → Envelope → Construction Assembly |
| Window shading control type, if applicable | Building → Envelope → Construction Assembly |
| Properties of shading material, if applicable | Building → Envelope → Construction Assembly |
| Type of material | Building → Envelope → Construction Assembly → Material |
| Surface roughness category | Building → Envelope → Construction Assembly → Material |
| Material thickness (m) | Building → Envelope → Construction Assembly → Material |
| Thermal conductivity (W/m·K) | Building → Envelope → Construction Assembly → Material |
| Density of construction material (kg/m³) | Building → Envelope → Construction Assembly → Material |
| Specific heat capacity (J/kg·K) | Building → Envelope → Construction Assembly → Material |
| Thermal absorptance (0–1) | Building → Envelope → Construction Assembly → Material |
| Solar absorptance (0–1) | Building → Envelope → Construction Assembly → Material |
| Visible absorptance (0–1) | Building → Envelope → Construction Assembly → Material |
| Solar heat gain coefficient of glass (0–1) | Building → Envelope → Construction Assembly → Material |
| Thermal transmittance of glass (W/m²·K) | Building → Envelope → Construction Assembly → Material |
| Visible light transmittance of glass (0–1) | Building → Envelope → Construction Assembly → Material |
| R-value in SI units (m²·K/W) | Building → Envelope → Construction Assembly → Material |
| R-value in IP units (hr·ft²·°F/Btu) | Building → Envelope → Construction Assembly → Material |
Building → Archetype, Climate & Geometry
| Description | System Path |
|---|---|
| DOE building archetype used for template selection | Building → Archetype |
| Whether building is residential or commercial | Building → Archetype |
| Internal building vintage classification | Building → Archetype |
| ASHRAE climate zone identifier | Building → Archetype |
| Year building was constructed | Building → Archetype |
| Weather station identifier used for EPW file | Building → Climate |
| Total conditioned floor area associated with building (ft²) | Building → Geometry |
| Number of above-grade floors (integer) | Building → Geometry |
| Number of below-grade floors (integer) | Building → Geometry |
| Length of longest building facade (ft) | Building → Geometry |
| Width of building footprint perpendicular to longest facade (ft) | Building → Geometry |
| Distance between floors (ft) | Building → Geometry |
| Ratio of building length to width | Building → Geometry |
| Depth of perimeter thermal zones (ft) | Building → Geometry |
| Basement type for residential buildings | Building → Geometry |
Impact on the Building Energy Model
While Tier-1 requests allow the specification of five major energy-usage determining building attributes, and the EnergyPlus energy models for each combination can therefore be built, simulated, and stored for quick access, Tier-2 requests have an almost infinite number of possibilities. Thus, they cannot be pre-simulated, and Tier-2 requests, no matter what method is used to create them, must create, run, and post-process one or more EnergyPlus models in the background of the request. If 10 EIMs are being analyzed, that would be 11 (one additional for the baseline) EnergyPlus models running in the background. This adds to the processing time of the request compared to Tier-1 requests.
The process of creating the energy models for any given Tier-2 request are as follows:
- Process user input into the standardized internal data definition format
- Using the standardized internal data definition, create an energy model of the building to represent its current state
- For each EIM, modify the energy model of the building’s current state to represent how the operations, equipment, and envelope of the building would change after the EIM was implemented
-
Simulate each energy model for every hour in a year, calculating the
energy usage of each piece of equipment (from boilers to plug loads)
for each energy type:
Electricity
Natural gas
Fuel oil
District heat (steam)
District heat (hot water)
Coal
- Calculate annual utility cost and emissions for the building
- Aggregate the energy usage, utility cost, and emissions for the building into the metrics displayed or returned to the user