Measure energy for exit signs in greenhouses. Enter wattage, quantity, runtime, and local tariff quickly. Get daily, monthly, and annual use with costs instantly.
| Scenario | Qty | W per sign | Hours/day | Rate | Annual kWh | Annual cost |
|---|---|---|---|---|---|---|
| Small greenhouse corridor | 4 | 2.0 | 24 | 0.22 | 84.68 | 18.63 |
| Garden center retail area | 10 | 3.5 | 24 | 0.20 | 349.76 | 69.95 |
| Older outbuilding fixtures | 6 | 8.0 | 24 | 0.22 | 458.37 | 100.84 |
Most exit signs operate continuously to protect staff routes through greenhouses, sheds, and retail aisles. Modern LED units often draw 1.5–3.5 W per sign, while older fluorescent styles can run 6–12 W. Incandescent panels may exceed 12 W and create extra heat near dry storage. In round‑the‑clock service, even small wattage differences compound into measurable yearly kWh and predictable utility spend.
Energy is calculated from total watts, hours per day, and billing days. For example, 10 LED signs at 2.3 W each, plus 0.3 W charging overhead and 5% losses, use about 0.69 kWh daily at 24 hours. At a 0.22 rate, that is roughly 0.15 per day, or about 55 per year. Scaling to 40 signs pushes annual energy near 1,000 kWh, which is worth tracking on farm budgets.
Facilities frequently schedule functional tests to verify emergency operation. The calculator adds a monthly test block in minutes, converted to hours and multiplied by total watts. A 30‑minute test once per month adds only a small fraction of annual kWh, but documenting it supports consistent maintenance planning across zones. If your program uses weekly checks, increase tests per month to reflect that cadence.
Drivers, wiring length, and conversion stages can add overhead beyond nameplate wattage. A 3–8% loss factor is common when accounting for power supplies and line losses on long runs. The tool also estimates current from watts and voltage, helping you review breaker loading and identify opportunities to group signage on efficient circuits. Lower current improves resilience on backup power and reduces nuisance trips during storms.
When you enter an emission factor, the report translates annual kWh into estimated kilograms of CO₂. This supports sustainability reporting for garden operations, especially when paired with fixture audits. If you replace 8 W fluorescent signs with 2.5 W LED units, annual energy can drop by roughly 65–75%, freeing budget for irrigation controls, sensors, and safer pathways. Track savings per zone to prioritize retrofits with the quickest payback, with simple reporting dashboards.
1) What wattage should I enter if the label is missing?
Use estimates: 2–3 W for LED, 8–10 W for fluorescent, and 10–15 W for incandescent. Replace with a measured value when you have a plug meter or clamp meter.
2) Why include battery or charger overhead?
Many emergency units maintain batteries continuously. That extra draw can be a meaningful share of efficient LEDs, so including it improves annual cost accuracy.
3) How do monthly test minutes affect the result?
The tool converts minutes to hours, multiplies by total watts, and adds the energy to monthly and annual totals. It is typically minor, but it aligns reports with routine checks.
4) What loss factor is reasonable?
Start with 0.05 for mixed drivers and wiring. Use 0.03 for short modern runs and 0.08 for long older circuits. If you measure true watts at the panel, reduce the factor.
5) Can I use this for multiple buildings?
Yes. Run separate calculations for each building or zone, then export CSVs for consolidation. This keeps assumptions consistent and makes retrofit prioritization clearer.
6) Which result should I use for budgeting?
Use annual cost for long‑term planning and monthly cost for bill comparisons. If you pay fixed charges, include them so the exported report matches your statement more closely.
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.