Inputs
Enter demand drivers, then compute the recommended generation capacity and storage buffer.
Example Data Table
| Scenario | Base Demand (L/day) | CIP Volume × Events | Operating Hours | Peak Factor | Yield (%) | Redundancy (%) |
|---|---|---|---|---|---|---|
| Packaging line | 8,000 | 500 × 1 | 16 | 1.3 | 92 | 15 |
| Multi-suite facility | 12,000 | 800 × 2 | 16 | 1.4 | 90 | 20 |
| High demand campaign | 20,000 | 1,200 × 2 | 20 | 1.6 | 88 | 25 |
Formula Used
How to Use This Calculator
- Enter your base daily demand from production, labs, and utilities.
- Add periodic cleaning demand using CIP volume and events per day.
- Set operating hours to reflect planned runtime and maintenance windows.
- Use a peak factor to cover short-term spikes and batch draws.
- Apply loop losses for sampling, drain, and circulation impacts.
- Choose yield to reflect upstream recovery and quality constraints.
- Add redundancy for reliability targets and contingency planning.
- Press Calculate, then export results using CSV or PDF buttons.
Demand profiling for WFI systems
Capacity planning begins with a clear demand map. Separate routine point-of-use consumption from periodic CIP/SIP draws, then confirm totals against shift patterns and campaign schedules. Converting daily volumes into hourly demand avoids undersizing when runtime is limited. Treat early assumptions as living data and refine them with flow logs and batch records.
Peak factors and growth allowances
Daily totals can hide short, high-intensity withdrawals. A peak factor represents simultaneity at multiple points of use, filling operations, and rapid turnarounds. Growth allowance adds measurable headroom for new suites or increased batch rates, reducing the chance of near-term upgrades. Use sensitivity runs to see how peak and growth change the design output.
Yield and recovery impacts on capacity
Yield is the portion of generated water that becomes usable WFI at delivery after rejects and operational losses. A lower yield increases required generation even when demand is unchanged. Base yield on validated performance data, and revisit it after changes to pretreatment, sanitization frequency, or quality constraints that affect rejects.
Redundancy and reliability planning
Redundancy converts reliability targets into capacity margin. It helps cover maintenance downtime, performance drift, and upset conditions without interrupting production. Compare the utilization result with your reliability goals: high utilization indicates limited resilience, while moderate utilization provides controllability and operational flexibility.
Storage buffer and operational controls
Storage smooths peaks and protects against short interruptions, but it should align with turnover and microbial control strategy. Buffer hours translate peak net demand into a working volume that supports stable generation and distribution. Use this estimate as a starting point, then confirm with draw profiles, control limits, sanitization approach, and operating procedures.
FAQs
It is the recommended generator output after applying peak demand, growth, loop losses, yield effects, and redundancy. It targets reliable delivery during worst credible operating periods.
Use historical draw data if available. Otherwise, start with 1.2–1.6 depending on simultaneity and batch draws, then verify using time-based consumption logs from key points of use.
Yield depends on recovery and rejects. Use validated operating data where possible. If unsure, use a conservative value and run sensitivity cases to see the impact on capacity.
Recirculation, sampling, drain events, and thermal losses can consume usable water. Adding loop losses helps prevent undersizing when the distribution system runs continuously.
Match it to criticality and maintenance strategy. Higher criticality systems often justify higher margins. Review utilization results to ensure adequate headroom during maintenance or upset conditions.
Not always, but it often improves stability by smoothing demand spikes and allowing continuous operation. Set buffer hours based on peak draws, risk tolerance, and operational constraints.
Yes. It provides a defensible estimate for capacity and buffer sizing. For final design, validate with detailed draw profiles, piping heat loss, sanitization strategy, and site-specific constraints.