How to Cut Electric Dehumidifier Costs in UK Homes

By AtheneNet Home & Money Desk

Reviewed: 16 August 2026

An electric dehumidifier can help control damp without becoming an unnecessarily expensive appliance. The biggest savings usually come from choosing the right location, keeping relative humidity between 50% and 60%, and letting the humidistat stop the machine once the target is reached. Households with a genuine off-peak electricity tariff may save more by shifting suitable drying sessions into cheaper hours.

The aim is not to run the dehumidifier for as little time as possible. It is to remove moisture efficiently, address the source of persistent damp and avoid paying to dry air entering through open windows or unused parts of the home.

Place the dehumidifier where it can collect moisture efficiently

Positioning affects how quickly a dehumidifier reaches its target. Place the unit on a level surface with the air inlet and outlet unobstructed. Follow the manufacturer’s clearance instructions rather than pushing it tightly against a wall, curtain, sofa or radiator.

For damp concentrated in one bedroom, utility room or bathroom, operate the machine in that room with external windows and doors closed. Closing the internal door can also help when treating a single space. If the objective is to reduce humidity across several connected rooms, leave internal doors open and use a central position such as a landing.

Avoid repeatedly moving a small unit around a large house. Moisture can migrate back into treated rooms, extending the total running time. It is normally more efficient to prioritise the dampest occupied area and then reassess the rest of the property with a hygrometer.

Useful placement checks include:

• Keep laundry close enough for dry air to circulate around it.
• Leave space between garments instead of packing them tightly together.
• Shut external windows while the appliance is operating.
• Keep the unit away from splashes and follow its electrical safety instructions.
• Do not cover the outlet or place clothes directly on the appliance.

Use a 50% to 60% humidity target instead of continuous mode

Relative humidity describes how much moisture the air contains compared with the maximum it could hold at the same temperature. A practical target for many UK homes is 50% to 60% relative humidity.

Start with a humidistat setting near 55%. The appliance should then cycle off when the room reaches the chosen level and restart only when humidity rises. Continuous mode can be useful for a short, intensive task such as drying washing, but leaving it active indefinitely may consume electricity after the main benefit has been achieved.

Do not assume that the lowest possible setting is best. Attempting to maintain an unnecessarily dry room can increase running time. A separate digital hygrometer is useful if the dehumidifier’s display is poorly positioned or appears inconsistent.

Room temperature also matters. Refrigerant or compressor models commonly become less effective in colder spaces, while desiccant models can perform better at low temperatures but often have a higher rated power. Compare expected operating conditions as well as the purchase price and extraction figure.

Compare power consumption with the area being treated

A dehumidifier’s rated wattage shows its maximum electrical demand, not necessarily what it will consume throughout every session. A humidistat-controlled compressor may cycle on and off, so a plug-in energy monitor can provide a more useful household-specific figure.

The table below uses illustrative power bands and assumes eight hours at full rated power. The cost column uses an example electricity rate of £0.25 per kWh; replace this with the unit rate on your bill. Room size is only a starting point because ceiling height, temperature, laundry and the severity of damp all affect demand.

Calculate your own maximum session cost with this formula:

Power in watts ÷ 1,000 × running hours × electricity unit rate

For example, a 300 W appliance running for five hours uses up to 1.5 kWh. At an illustrative rate of £0.25 per kWh, that would cost up to £0.375, or about 38p. Actual consumption may be lower if the compressor cycles off.

A larger unit is not automatically more expensive for a particular job. If it reaches the target quickly and switches off, it may use less electricity than an undersized machine running continuously. Compare measured kWh per completed drying task rather than wattage alone.

Shift suitable sessions to off-peak tariff hours

Off-peak operation only reduces cost when the household’s tariff genuinely charges less at certain times. Economy 7, time-of-use and electric-vehicle tariffs can have different schedules, while some standard tariffs charge the same rate all day.

Check the exact unit rates and hours on your tariff before setting a timer. Then compare the cost of a session in each period:

Session energy in kWh × applicable unit rate

Laundry drying is often the easiest task to schedule because it has a clear beginning and end. Place the washing on an airer in a closed room, select an appropriate laundry or humidistat mode and use the appliance’s timer if the manual permits unattended timed operation.

Do not delay necessary moisture control solely to reach a cheaper tariff window if condensation is actively accumulating. Persistent water on windows, walls or furnishings requires attention to ventilation, heating patterns, leaks and other causes as well as appliance timing.

Reduce the number of hours the appliance needs

Maintenance and everyday moisture control can shorten future sessions. A blocked filter restricts airflow, while a full tank may stop the machine before it completes the job.

Keep airflow and drainage working properly

Inspect and clean the filter at the interval specified by the manufacturer. Empty the tank promptly, or use continuous drainage only when the model supports it and the hose can be installed securely with the correct fall.

Dust the inlet and outlet without allowing water into electrical components. If performance suddenly declines, check the filter, room temperature, placement and humidity reading before extending the timer.

Deal with moisture at its source

Use extractor fans during and after cooking or showering, keep pan lids on where practical and avoid drying washing across several rooms. Repair plumbing leaks and investigate rain penetration rather than relying on a dehumidifier to mask them.

Ventilation and dehumidification should work together. Brief, purposeful ventilation can remove moisture, but leaving a window open beside an operating dehumidifier makes the appliance process a continuing supply of outside air.

Follow these steps for a lower-cost drying routine

1. Use a hygrometer to identify the dampest occupied room and record its starting humidity.
2. Close external windows and remove obvious moisture sources such as wet towels or uncovered pans.
3. Position the dehumidifier with the manufacturer’s required clearance around its inlet and outlet.
4. Set the humidistat near 55%, keeping the normal target within the 50% to 60% range.
5. Check whether your electricity tariff has cheaper hours and schedule suitable sessions accordingly.
6. Measure energy use for a typical session with the appliance display or a compatible energy monitor.
7. Stop continuous mode once the immediate drying task is complete and return to humidistat control.
8. Clean the filter, empty the tank and compare humidity readings over several days.

Review the next bill alongside your measured kWh rather than judging savings from running hours alone. If humidity remains high despite correct placement and regular operation, investigate leaks, inadequate extraction, cold surfaces or structural damp before buying a more powerful machine. Energy Saving Trust guidance can also help households examine appliance use within their wider home-energy costs.

Source: Energysavingtrust