Pick a workflow, enter what you know, and the inputs update live. Baseline calculations begin after an EnergyPlus sizing run; proposed calculations come straight off the fan-coil schedule. Reference tables are at the bottom of the page.
1
Select your baseline system
Choose the Appendix G baseline system for your building. Not sure which applies? Pick by building type instead.
| Building type | Fossil fuel / hybrid / purchased heat | Electric & other |
|---|---|---|
| Residential | ||
| Nonresidential, ≤3 floors and <25,000 ft² | ||
| Nonresidential, 4–5 floors and <25,000 ft², or ≤5 floors and 25,000–150,000 ft² | ||
| Nonresidential, >5 floors or >150,000 ft² |
2
Enter the design supply airflow
Run an EnergyPlus sizing run first, then read the “Maximum Air Flow Rate” from the Fan section of the output. Enter it in either unit.
3
Pressure-drop adjustment A
From Table 6.5.3.1.1B. Sum any applicable credits/deductions. Use 0 to be conservative (baseline default).
| Device | Adjustment |
|---|---|
| Credits | |
| Fully ducted return and/or exhaust air systems | 0.5 in. w.c. |
| Return and/or exhaust airflow control devices | 0.5 in. w.c. |
| Exhaust filters, scrubbers, or other exhaust treatment | Device ΔP at design condition |
| Particulate filtration: MERV 9–12 | 0.5 in. w.c. |
| Particulate filtration: MERV 13–15 | 0.9 in. w.c. |
| Particulate filtration: MERV 16+ / electronically enhanced | 2× clean-filter ΔP at design |
| Carbon / gas-phase air cleaners | Clean-filter ΔP at design |
| Heat-recovery device | Device ΔP at design |
| Evaporative humidifier/cooler in series with cooling coil | Device ΔP at design |
| Sound attenuation section | 0.15 in. w.c. |
| Deductions | |
| Fume-hood exhaust exception (per 6.5.3.1.1 Exception [c]) | −1.0 in. w.c. |
4
Motor efficiency
Per Appendix G, use the next motor size greater than the brake horsepower in the Enclosed / 1800 RPM column of Table 10.8. The suggested motor is selected automatically; override it if your design differs.
Auto-filled from Table 10.8 · editable
5
Assumed total efficiency
EnergyPlus fan power depends only on the ΔP-to-efficiency ratio, so total efficiency is fixed at 70 % per the baseline method (G3.1.2.9). This value is locked — the resulting delta pressure carries the calibration.
EnergyPlus inputs SYSTEM
Select a system and enter the design airflow to see your EnergyPlus inputs.
QA/QC — verify against a completed baseline simulation
▸After running the baseline simulation, enter the values from the Fan section of the output table. Relationships should agree within 5 %.
Reference tables
▸ASHRAE 90.1-2007 Appendix G — Tables G3.1.1B, 6.5.3.1.1B, and 10.8.