Configuration
The Configuration pane is where you set up the HVAC equipment for each system. Equipment is defined by its components: you enable the components each unit has (coils, outside air, energy recovery, return air) and configure each one, rather than picking from a list of named equipment types.
Central Unit Configuration
Section titled “Central Unit Configuration”Components
Section titled “Components”Enable the components your central unit has:
- Outside Air - The unit brings in outdoor air for ventilation
- ERV - An energy recovery wheel preconditions outdoor air with exhaust air
- Return Air - The unit recirculates return air
- Cooling Coil - The unit provides cooling
- Heating Coil - The unit provides heating
Outside Air
Section titled “Outside Air”Choose how the outdoor airflow is determined:
- Sum of Spaces - Total of each space’s ventilation requirement
- Multi-Zone - ASHRAE 62.1 multi-zone calculation using system ventilation efficiency
- Percent - A fixed percentage of supply air
- Custom - A fixed flow rate you enter
For units with an energy recovery wheel, set the ERV Wheel Effectiveness — the fraction of the exhaust-to-outdoor-air temperature difference recovered.
Cooling Coil
Section titled “Cooling Coil”- Coil Type - Chilled Water or Direct Expansion
- CHW ΔT - Chilled water temperature rise, for chilled water coils
- Cooling Supply Air Temperature - Design temperature of air leaving the coil; typically 55°F (13°C) for dehumidification
Heating Coil
Section titled “Heating Coil”- Coil Type - Heating Hot Water, Direct Expansion, Gas Fired, or Electric
- HHW ΔT - Heating water temperature drop, for hot water coils
- Heating Supply Air Temperature - Design temperature of air leaving the coil
Supply and Return Air
Section titled “Supply and Return Air”Account for gains and losses between the unit and the spaces:
- Fan Heat Gain - Heat added to the airstream by the supply fan motor
- Other System Inefficiencies - Miscellaneous system losses
- Supply Duct Heat Gain/Loss and Supply Duct Leakage
- Return Duct Heat Gain/Loss and Return Duct Leakage
Energy Settings
Section titled “Energy Settings”For energy estimates, configure:
- Heating Equipment Type - Heat pump (electric) or gas furnace
- Cooling SEER - Cooling efficiency (BTU/W·hr)
- Heating COP - Heat pump coefficient of performance
- Heating AFUE - Gas furnace efficiency
- Operating Schedule - 24/7, 9am-5pm, or a custom hourly schedule
- Hours of Warm-up and Warm-up Capacity - Morning warm-up before occupancy
Terminal Unit Configuration
Section titled “Terminal Unit Configuration”Terminal units are configured per zone using the same component approach:
- Return Air Component - Whether the terminal recirculates zone air
- Cooling Coil Component and Heating Coil Component - With the same coil type, ΔT, and supply air temperature settings as central units
- Outside Air Method - How outdoor air is apportioned to the terminal
- Pressure Loss - The terminal’s air pressure drop, used in duct pressure calculations
For example, a VAV box with hot water reheat is a terminal with a heating coil (Heating Hot Water) and no cooling coil, while a four-pipe fan coil has both coils.
Verification
Section titled “Verification”After configuration, verify:
- Capacity meets peak loads
- Airflow is adequate for ventilation
- Pressure drop is within limits
- Equipment selections are realistic