HVAC Ductwork, Air Handling & Mechanical Products calculator
Fan Energy Index Margin Calculator
Compare submitted fan energy index with the project requirement. Enter both FEI values at the same airflow, pressure and rating basis.
What this calculator does
- Compare submitted fan energy index with the project requirement.
Formula used
- FEI margin = Submitted FEI − Required FEI
- Relative margin % = FEI margin × 100 ÷ Required FEI
Inputs explained
- Submitted Duty-Point FEI: Submitted fan energy index at the required duty point.
- Required Duty-Point FEI: Minimum index stated for that same duty point.
How to use the result
- Best suited to fan submittal reviews, Duty-Point rating comparisons.
- This is a submitted-rating comparison, not certification or code compliance review.
Current U.S. benchmarks
- Industrial electricity averages 9.77 cents per kWh across the U.S. (EIA, Jul 2026), up 4.7% from a year earlier. Energy-intensive steps carry this directly into unit cost.
- U.S. housing starts run at 1,275k per year (Census, Aug 2026), down 1.2% from a year earlier, the demand driver for building products.
Common questions
- What does FEI compare? FEI compares reference electrical input power with actual electrical input power at the specified duty point.
- Can I compare values at different airflows? No. Use the same duty point and rating basis.
- Does this calculate a new FEI? No. It compares an entered submitted value with an entered requirement.
- Does a positive margin prove compliance? No. Verify the source rating and every applicable project or code requirement separately.
Last reviewed 2026-10-12.