Retrofit AC Fan to EC: ROI Calculation Guide
A practical payback formula for AHU, CRAH and refrigeration retrofits
AC-to-EC retrofit payback depends on power reduction, operating hours, electricity price, installation cost and avoided maintenance. High-hour variable-load systems usually produce the fastest return.
Key Takeaways
- Annual saving = power reduction × operating hours × electricity price.
- The best candidates run more than 4,000 hours per year or use damper throttling.
- Retrofit feasibility must include mounting, wiring, controls and access time.
Engineering Notes
Start with a simple formula: annual kWh saved = (old fan kW at the same duty point − new EC fan kW at the same duty point) × annual operating hours. Annual cost saved = annual kWh saved × electricity price.
Payback period = installed retrofit cost ÷ annual cost saved. If maintenance savings or downtime reduction are material, add them to the annual benefit rather than hiding them in a vague claim.
LONGWELL retrofit candidates often include LWBE3G for plug-fan and centrifugal replacements, LWAE3G for axial/condenser applications and Fan Grid modules for AHU or CRAH modernization.
Product and Application Images
Selection Table
| Item | Market / legacy condition | Engineering recommendation |
|---|---|---|
| Scenario | Typical retrofit value | Reason |
| Office AHU | Medium | Moderate operating hours and variable load |
| Hospital / hotel AHU | High | Long operating schedule and comfort requirement |
| Data center CRAH | Very high | 24/7 operation and redundancy value |
| Cold-chain evaporator/condenser | High | Long runtime and refrigeration efficiency impact |
Related LONGWELL Product Categories
Related Resources
FAQ
What information is needed for a retrofit ROI estimate?
Which sites usually pay back fastest?
Should a retrofit page promise a fixed payback?
Need a replacement model or OEM validation?
Send the existing model, airflow, static pressure, voltage, control signal, mounting dimensions and annual quantity. LONGWELL can check the closest platform for your project.
Contact sales@longwellfans.com Open cross-reference