Now browser-based
EnergyPlus Fan Energy Calculator
An interactive tool for deriving the supply-fan inputs EnergyPlus needs — total efficiency, delta pressure, and motor efficiency — from ASHRAE 90.1-2007 Appendix G baseline equations or from equipment specifications.
This tool replaces the original Fan Calculator spreadsheet with a guided web version. It runs entirely in your browser — nothing to download — and computes the three supply-fan parameters required by EnergyPlus:
- Supply Fan Total Efficiency
- Supply Fan Delta Pressure {Pa}
- Supply Fan Motor Efficiency
Two workflows
Baseline system
ASHRAE 90.1 Appendix G
Select a baseline system (1–8) or pick by building type, then enter the design airflow from your EnergyPlus sizing run. The tool applies the Appendix G fan-power equations, selects the motor from Table 10.8, and returns the three inputs.
Proposed system
From equipment specifications
Enter the airflow, minimum outside air, pressure drop, fan power, and motor efficiency from the fan-coil schedule. The tool returns total efficiency, delta pressure, and the cubic-metre-per-second flow rates for the system HVAC template.
What the web version adds
- Guided single-page workflow with live calculation
- Automatic motor selection from Table 10.8
- Inline derivation of each equation as you enter values
- Copy-ready EnergyPlus inputs
- Built-in QA/QC check against simulation output
- Works on desktop, tablet, and phone
Methodology. Baseline calculations follow ANSI/ASHRAE/IESNA Standard 90.1-2007, Appendix G (Tables G3.1.2.9, 6.5.3.1.1B, and 10.8). The resulting inputs are calibrated to the EnergyPlus simple fan model (Fan:ConstantVolume / Fan:VariableVolume / Fan:OnOff) so the simulated fan power reproduces the Appendix G value. All calculations run locally in the browser with no external dependencies.