Use a measured kWh total and an observation period to estimate running cost. The calculation is energy × electricity rate; the uncertainty is whether that observation represents the period you want to budget for.
Calculate your measured running cost
Use energy from a representative measurement period. The starting values are an illustration, not a product test.
Example: 4 kWh/day × $0.18/kWh × 30 days = $21.60.
Energy charge only; future weather, runtime and utility fees can change the bill.Worked example: one week to a 30-day estimate
The calculation is simple: cost = energy in kWh × your applicable price per kWh. Virginia Cooperative Extension’s energy-use guide explains the relationship between power, time, energy and utility cost. The examples below are hypothetical arithmetic, not measurements from an Argendon unit.
| Example input | Value |
|---|---|
| Energy over 7 days | 28 kWh |
| Average energy per day | 28 ÷ 7 = 4 kWh |
| Illustrative variable electricity rate | $0.18/kWh |
| Estimated 30-day energy cost | 4 × 30 × $0.18 = $21.60 |
The $21.60 result assumes the same average daily energy use throughout all 30 days at the illustrative $0.18/kWh rate. It is not an Argendon test result or a forecast for a wetter month.
Collect inputs that belong together
- Read starting and ending kWh and record the elapsed days. Use a suitable measuring device without defeating the appliance’s electrical instructions.
- Record the humidity target, operating mode, achieved room humidity and unusual weather.
- Use the applicable variable tariff. For time-of-use pricing, calculate each price period separately; fixed service charges need separate treatment.
If you only know watts and hours
If a hypothetical unit draws 400 watts while actively running for 10 hours, that portion of its day uses 400 × 10 ÷ 1,000 = 4 kWh. Add other operating states if they consume energy. Do not assume fan-only operation, standby or pump activity is already included unless the measurement covers them.
Label this an assumption-based estimate. Rated current is not daily energy consumption, and voltage multiplied by nameplate current is not an exact running-cost measurement.
Keep the humidity result beside the cost
Initial drying, settled maintenance and a wet week can produce different energy totals. Repeat after a material change in conditions or the humidity setting.
A lower cost is not an improvement if the basement is now too damp. Keep the achieved humidity and area served alongside the cost rather than reporting a falsely precise annual total.
