Cost to Dry Clothes With a Dehumidifier in the UK

The Calculation That Does Not Go Out of Date

Calculate the electricity used for the completed drying job, then multiply by your current unit rate.

If you know the dehumidifier's energy use in kWh for the whole session, multiply that figure by your electricity price per kWh. This is the cleanest comparison because tariffs change over time.

If you only know rated power, estimate energy as watts ÷ 1,000 × hours. For example, 250W running for eight hours at continuous rated power is 2.0 kWh. Multiply 2.0 by your own unit rate to estimate the session cost. A compressor model may consume less than the simple rated-power estimate if it cycles during the session.

• Energy estimate: watts ÷ 1,000 × hours = kWh
• Cost estimate: kWh × electricity unit rate
• Standing charge is normally excluded from marginal appliance cost because it is payable regardless
• A plug-in energy monitor can give a better real-world session figure than rated wattage alone

Why There Is No Honest Universal Cost Per Load

Two households can use the same dehumidifier and get different completed-load costs.

Which? notes that indoor-drying economics depend on factors including the amount of laundry, while its dehumidifier guidance treats the appliance as one option for helping indoor laundry dry [S1][S3].

Runtime changes with how much water remains after the washing-machine spin, garment spacing, airflow, room temperature and humidity, appliance technology and the point at which you decide the load is dry. That makes a fixed national pence-per-load claim misleading.

• More residual water usually means more drying work
• Poor spacing and airflow can extend the job
• Room temperature and humidity affect dehumidifier performance
• Compressor cycling means rated watts are not always average watts

Dehumidifier vs Tumble Dryer: Compare the Same Job

Compare measured or labelled kWh for a completed load rather than assuming one technology always wins.

Tumble dryers vary substantially by technology and efficiency. Energy Saving Trust notes that heat-pump tumble dryers recycle heat and are more efficient than conventional alternatives [S4]. Which? also finds that the cheapest indoor-drying method depends on the amount of laundry and the equipment being compared [S1].

For a fair household comparison, dry a similar load to the same end point, record total kWh for each method, and multiply both by the same tariff. Include repeat sessions if a rack or appliance cannot handle the whole load at once.

• Do not compare only watts or pence per hour
• Use total kWh for the completed load
• Separate heat-pump dryers from condenser or vented dryers when comparing
• Include capacity and repeat cycles or sessions

Drying Laundry Without Creating a Moisture Problem

A dehumidifier can remove excess moisture from room air, but it is not a substitute for appropriate ventilation or fixing a damp defect.

Energy Saving Trust says a dehumidifier can help with excessive moisture and drying washing indoors [S2]. Its ventilation guidance also makes clear that dehumidifiers remove moisture from existing air but do not provide fresh air [S5].

Current UK government damp-and-mould guidance says condensation can be driven by moisture from activities including drying laundry and that the correct response depends on the dwelling, including ventilation, heating, energy efficiency and any building deficiencies [S6].

• Keep existing ventilation routes functioning
• Do not treat a dehumidifier as a repair for leaks or penetrating damp
• Persistent condensation or mould needs the underlying moisture source investigated
• Use the home humidity checker if you want to monitor the room while drying

How to Measure Your Real Cost at Home

Run one normal laundry load and record the actual electricity used from start to your normal dry end point.

Start with a normal washing-machine spin, arrange the laundry as you usually would and use the same room and dehumidifier settings you plan to use regularly. A plug-in energy monitor can record the kWh consumed by the dehumidifier during the session.

Repeat the test with another representative load if you want a more useful household average. Then enter the measured energy or equivalent wattage/runtime into the DryHomeLab calculators using your current tariff.

• Record load size and spin setting
• Record total drying runtime
• Measure kWh if possible
• Note whether window condensation appeared
• Repeat with a representative second load before treating one result as typical

Frequently asked questions

Bottom line

The useful answer is not a fixed pence-per-load number. Measure or estimate the dehumidifier's total kWh for a completed laundry load, multiply by your current electricity tariff, and compare that result with alternative drying methods on the same completed-load basis. This stays accurate as tariffs and appliance choices change.