Model ventilation upgrades and savings in minutes. See cashflow, emissions impact, and payback for projects. Make smarter retrofit choices with clear financial results today.
| Scenario | Fan kW | Hours/Day | Days/Year | Rate | Improvement | Net Investment | Year-1 Savings | Payback |
|---|---|---|---|---|---|---|---|---|
| Office AHU Controls | 2.2 | 12 | 320 | 0.18 | 22% | 3,000 | 485 | 6.2 yrs |
| Retail VFD Retrofit | 3.5 | 14 | 330 | 0.20 | 28% | 5,500 | 2,400 | 2.3 yrs |
| Warehouse Scheduling | 1.6 | 10 | 300 | 0.16 | 18% | 1,200 | 350 | 3.4 yrs |
Ventilation savings start with realistic runtime assumptions. For example, a 2.2 kW fan operating 12 hours/day for 320 days uses about 8,448 kWh annually. If controls and balancing deliver a 22% improvement, annual savings approach 1,859 kWh before any heat recovery credits. Small changes in hours or days can shift results materially, so confirm schedules with BMS trends or logbooks.
Electricity rate is the strongest financial driver. At 0.18 per kWh, 1,859 kWh saves roughly 335 in year one. With 3% escalation, the same kWh reduction grows to about 437 by year ten. If your tariff includes time-of-use or demand components, consider using an effective blended rate that reflects those charges.
Net investment equals upfront cost minus incentives. A 3,500 upgrade with a 500 rebate requires 3,000 net capital. Maintenance savings, such as fewer filter changes or reduced callouts, can add steady value; entering 150 per year increases year-one total savings to about 485 in the sample case. Capture only savings you can defend in documentation.
Simple payback divides net investment by year-one total savings; 3,000 divided by 485 is about 6.2 years. NPV discounts future savings using your selected rate, helping compare projects with different lifetimes. IRR estimates the implied return of the savings stream; treat it as a planning indicator rather than a guaranteed yield, especially when load or pricing uncertainty is high.
The calculator also estimates avoided emissions using a CO2 factor. With 0.45 kg per kWh, 1,859 kWh avoided reduces about 0.84 tonnes of CO2 each year. Pair this figure with utility documentation or grid disclosures for reporting consistency. When presenting results, cite assumptions, include a sensitivity range, and revisit inputs after commissioning verifies performance. For many buildings, ventilation measures deliver hidden comfort benefits, but financial approval typically depends on measured savings and documented persistence over several seasons.
Any change that reduces fan energy or improves recovery, including controls, VFDs, scheduling, balancing, duct sealing, better filtration strategy, or heat recovery additions.
Use commissioning reports, vendor projections, or measured kW reductions before and after upgrades. If unsure, start with 10–25% and run a sensitivity range to bracket outcomes.
Energy rates often trend upward over time. Escalation increases future savings while NPV discounts them back, giving a balanced view of long-term value.
Enter an annual average. If schedules differ widely, calculate weighted hours and days from BMS logs, then rerun scenarios for peak and off-peak operating periods.
Yes. Maintenance savings are added to annual benefits and flow through payback, NPV, ROI, and IRR. Only include savings you can verify and sustain.
Prefer your utility or national grid factor. If unavailable, use a conservative estimate and document the source. Consistent factors help compare projects across sites.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.