Dehumidifier running costs in the UK

Choose the input that matches your measurement

For example, if a suitable energy meter records 1.2 kWh during one full day, that day costs £0.32 at the example rate of 26.32p/kWh. This is an illustrative reading, not expected daily use. A changing room temperature, moisture load or setting can change the next day.

• Metered energy: enter the kWh recorded and the elapsed measurement days. For a cumulative meter, subtract the start reading from the end reading. Monthly and annual projections assume that daily average continues.
• Energy per use: enter the complete kWh for one session, such as a measured laundry-drying task. Include its whole operating period and choose your own session schedule.
• Watts and hours: use average watts at 100% duty, or an explicitly estimated active-power schedule. A nameplate or condition-specific wattage is not automatically the average while connected.
• Annual energy: use a documented annual kWh figure only for its stated test or usage scenario. Do not enter litres/day or the printed annual cost as kWh.

What the humidistat and fan change

A humidistat can stop or restart dehumidification as humidity changes. That does not establish a universal daily runtime or duty cycle. Some operation can continue while the compressor is off.

For example, the June 2021 Arete One 20L/25L manual describes periodic fan humidity checks in Smart Humidity mode and fan operation during compressor pauses in Smart Laundry mode. This is model- and mode-specific behaviour, not a rule for every dehumidifier.

A complete-period energy measurement includes the powered operation during that period. Do not reduce measured kWh again with a duty-cycle percentage. If you estimate separate operating modes, count each interval and its energy once.

Compressor or desiccant: which costs less?

The type label or lower rated watts alone cannot identify the cheaper option for your room. Compare the electricity needed to achieve the same moisture-control task, within each model’s specified operating conditions. Temperature, humidity, settings and runtime matter.

Check that capacity and efficiency figures use compatible test conditions and methods. ENERGY STAR describes integrated energy factor as litres removed per kWh under its test basis; a ratio made from a household water collection or the table above is not a certified efficiency rating.

A dehumidifier can discharge warmer air, but that is not evidence of a fixed heating-bill saving. This calculator prices its electricity and does not deduct an assumed heating credit.

Using a dehumidifier to dry clothes

Compare complete loads with comparable starting moisture and final dryness. Include the full dehumidifier session and any separate heated-airer or additional room-heating energy used for that task. Do not add supporting energy again if the meter reading already includes it.

A laundry-mode timer is not a guarantee that every load will finish in that time. Water collected can also come from other room moisture, so litres collected alone do not prove that two drying methods completed the same laundry task.

• Compare complete-load drying costs, including supporting dehumidifier energy

Apply your tariff and actual use schedule

Cost in pounds = kWh x your electricity price in p/kWh / 100. The daily standing charge is separate because switching this appliance off does not remove the household charge.

On Economy 7 or another time-of-use tariff, price each period’s energy at its applicable rate and add the amounts. There is no automatic night-time saving on a single-rate tariff.

In watts-and-hours mode, the monthly equivalent uses 30.44 use days. Set annual use-days to your expected season; a 365-day total is not a recommendation to run the appliance all year. All future costs hold the entered tariff constant.