UV System Sizing Calculator

Plan UV capacity for cleaner irrigation water daily. Tune dose, flow, and lamp type fast. Get clear sizing guidance for safer gardens every season.

Enter System Details
Use measured values when possible. This tool estimates sizing for irrigation disinfection.
Enter a steady design flow, not peak spikes.
Pick the unit that matches your pump specs.
Typical clear water: 85–95% at 254 nm.
Dose needs vary by target and water quality.
Common ranges: 30–80 mJ/cm² for irrigation control.
Choose the closest source category.
Closed chambers usually deliver more consistent dose.
Lamp type affects efficiency and footprint.
Accounts for hydraulics, geometry, and mixing.
Covers uncertainty, aging, and operating variance.
Covers sleeve scaling and biofilm growth.
Used to estimate daily energy consumption.
Finer filtration improves UV reliability.
Iron can reduce UV effectiveness through absorption.
Particles scatter UV and create shadowing effects.
Reset CSV (history) PDF (latest)
Example Data Table
Sample entries to show how results may look.
Flow UVT Dose Lamp Type UV Power Lamps Energy/day
25 gpm 90% 40 mJ/cm² Low-pressure (60 W) ~85 W 3 ~2.16 kWh
60 L/min 88% 60 mJ/cm² Amalgam (120 W) ~160 W 2 ~2.88 kWh
4 m³/h 80% 80 mJ/cm² Medium-pressure (250 W) ~420 W 10 ~30.00 kWh
Formula Used
A practical sizing method for irrigation systems.
  1. Dose relationship
    Dose (mJ/cm²) = Intensity (mW/cm²) × Exposure time (s). Therefore, Exposure time = Dose ÷ Intensity.
  2. Intensity proxy
    Average intensity is reduced by UVT, reactor efficiency, and water quality penalties (prefilter rating, turbidity, and iron). The tool combines them into an attenuation factor.
  3. Reactor volume
    Reactor volume (L) ≈ Flow (L/min) × Exposure time (s) ÷ 60.
  4. Required UV power
    UV power (W) is scaled with Flow × Dose, then increased by safety and fouling factors. Lamp count is based on the selected lamp’s germicidal fraction estimate.
How to Use This Calculator
A simple workflow for gardeners and irrigation managers.
  • Measure your steady design flow rate from pump or meter.
  • Enter UVT% from a lab test when possible.
  • Pick a target and set a design dose matching your goals.
  • Use realistic safety and fouling factors for maintenance intervals.
  • Add prefilter, turbidity, and iron to reflect water clarity.
  • Review results, then export CSV or PDF for your records.
Tip: If UVT is low or turbidity is high, improve filtration before upsizing UV.

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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.