Using a Dehumidifier to Remove & Prevent Mould

There are many factors that contribute to mould growth, but one of the main culprits is excessive moisture being present. All types of mould require moisture for it to thrive, so by limiting the moisture in your home, you can effectively help prevent and eliminate mould infestations. This when a dehumidifier can help; they are machines that reduces the level of humidity in the air, and therefore keeps the RH (Relative Humidity) at a reasonable level.

What is a dehumidifier?

A dehumidifier is a household appliance that reduces moisture from the air. They come in different shapes, sizes and capacities; suitability will often depend on the severity of the humidity and the size of your home and/or area you wish to reduce moisture from.

Dehumidifiers can be required for multiple reasons, but frequently for the following reasons:

  • To remove/prevent mould
  • To remove musty smells/odours
  • To help eliminate condensation e.g. condensation on windows/glasses or fog/vapour on glass are commonly signs that there is too much moisture in the room.
  • For health reasons

A few recommended dehumidifiers

Here’s a range of recommended dehumidifiers, suitable for small to larger spaces.

ImageName / DescriptionTypeSuitable forPrice
500ml AirPro Mini Compact Air Dehumidifier for Home, Kitchen, Bedroom, Bathroom, Caravan etc500ml AirPro Mini Compact Air Dehumidifier for Home, Kitchen, Bedroom, Bathroom, Caravan etcMechanical1 Small Room£33.31
Pro Breeze 1500ml Dehumidifier for Damp, Mould, Moisture in Home, Kitchen, Bedroom, Caravan, Office, GaragePro Breeze 1500ml Dehumidifier for Damp, Mould, Moisture in Home, Kitchen, Bedroom, Caravan, Office, GarageMechanical1 - 2 Rooms£79.99
De'Longhi DEM10 Compact Dehumidifier, 10LDe'Longhi DEM10 Compact Dehumidifier, 10LMechanical2/3 Bed House£139.85
EcoAir DD122 Simple Desiccant Dehumidifier, 7 L - BlueEcoAir DD122 Simple Desiccant Dehumidifier, 7 L - BlueDesiccant3/4 Bed House£129.95
Prem-I-Air Elite 10L Xtreem 10 Dehumidifier w/ 1.5 L Tank Capacity Type UK ModelPrem-I-Air Elite 10L Xtreem 10 Dehumidifier w/ 1.5 L Tank Capacity Type UK ModelMechanical2 Bed House£167.99
EcoAir DD122FW-MK5 Classic Desiccant Dehumidifier with Ioniser and Silver Filter, 7 L - BlueEcoAir DD122FW-MK5 Classic Desiccant Dehumidifier with Ioniser and Silver Filter, 7 L - BlueDesiccant2 - 5 Bed House + Small Office£168.15
Ebac 2650e 18 Litre Dehumidifier for Condensation, Damp and Mould with Smart Auto-Function, ​Laundry Boost and Air Purification Mode, Free 2 Year Warranty, WhiteEbac 2650e 18 Litre Dehumidifier for Condensation, Damp and Mould with Smart Auto-Function, ​Laundry Boost and Air Purification Mode, Free 2 Year Warranty, WhiteMechanical3 - 5 Bed House£169.00
Meaco Portable Compact Dehumidifier DD8LMeaco Portable Compact Dehumidifier DD8LDesiccant3 - 5 Bed House + Small Office£185.95

Please note that we do our best to keep all the information as accurate and updated as possible. However, some times details may not get updated immediately, so prices may differ from what we have listed (e.g. special discount offers).

More about dehumidifiers

How much does a dehumidifier cost to buy?

Because dehumidifiers drastically vary in sizes, and most importantly capacity, they can range from £20 – £300. Essentially, the higher end models are more powerful and they will be able to reduce moisture from larger areas at a quicker rate.

How much does a dehumidifier cost to run?

They aren’t really that expensive to run, and it will mostly depend on how much power the dehumidifier you’re using requires to run. The average running cost is somewhere in the range of 3p – 8p per hour.

It’s worth noting that it will cost more to run models that extract more water because they generally have higher power consumption. So you will effectively pay for what you get.

How noisy is a dehumidifier?

This is a major concern for many homeowners as dehumidifiers are notoriously noisy, and they can disturb sleep if they’re running through the night while in close proximity to bedrooms.

Fortunately, as technology has evolved, dehumidifiers are getting quieter (meaning more bearable). Also, most dehumidifiers have power settings, such as low, medium and high. The lower settings generally make less noise. When set to low, some are as quiet as a person whispering. If you need a dehumidifier running 24 hours a day, you could reduce the level during the night, and increase power during the day.

Where should I put my dehumidifier in the house?

The preferred position of the dehumidifier will mostly depend on circumstance.

If you’re trying to reduce moisture in a single room, the appliance should be placed at least 6-8 inches out from a wall so that air flow is not compromised.

If you’re trying to reduce moisture in an entire house, it’s best left in a main hall way, which connects to several rooms. For particularly larger properties, it might be worth investing in a couple of dehumidifiers.

For properties with multiple floors, you may need to move the appliance between floors, unless you buy multiple machines.

Desiccant Vs Mechanical

When you’re looking into purchase a dehumidifier, you may notice that some are mechanical, while others are desiccant. It’s important to know the difference between the types as it may determine which is more suitable for your purposes.

Desiccant Dehumidifiers

A desiccant dehumidifier uses a desiccative, which is a drying substance, to remove moisture from the air. They’re generally considered more environmentally friendly as they do not use compressors to function, which also make them cheaper to run. They are generally cheaper to purchase too.

Desiccant dehumidifiers are best used in high humidity and low temperature areas e.g. in the UK. They can work from temperatures from 0 degrees C.

Mechanical Dehumidifiers

Mechanical Dehumidifiers are a lot more common than desiccant models. They work similarly to air conditioning units, but they raise the air temperature as opposed to cooling it. They’re similar in the sense that they pass through air through hot/cold coils. Mechanical Dehumidifiers use compressors, which means it emits greenhouse gases, which makes it the less environmentally friendly option.

They work well in conditions with temperatures over 5 degrees C, and may fail to work properly if temperatures are below.

Mechanical dehumidifiers are ideal for moderate to high humidity areas (70% and plus relative humidity). It’s important to note that at approximately temperatures of 15 degrees C the average mechanical dehumidifier is more expensive to run than a desiccant dehumidifier. They actually get cheaper to run the higher the outside air temperature is.

Conclusion

If you’re in the UK, or in a country with similar climates, a desiccant dehumidifier is better suited, and that’s because:

  • Cheaper to run and buy (generally)
  • Able to continue operating at temperatures under 5 degrees C (which is often the case in the UK)
  • Quieter than mechanical machines
  • Environmentally friendly

Tips for buying a dehumidifier

1) Noise control

Most dehumidifiers will include how much noise they make in the spec. While all dehumidifier do differ, a low setting on a dehumidifier is typically as loud as a person whispering or approx 35dB. A high setting can be compared to a desk top fan operating at full speed, which of course, can be considerably noticeable, and that’s why it’s always advised to get one which allows for different settings.

2) Extraction rate

This is probably what most consumers will be concerned about- how effective the appliance is at removing moisture from the air.

The extraction rate is the maximum amount of moisture that the dehumidifier can extract with in 24 hours of running. The rates are typically from 8 to 14 litres, but of course, that will depend on the specific model. The more expensive/powerful dehumidifiers generally have a higher extraction rate. Take a look at the spec of each model to determine how effective it is.

3) Humidistat

A humidistat works much like “climate control”, it measures the relative humidity in the room, and it keeps it at a pre-set level, and some even have the capability of turning the dehumidifier on and off when certain levels are reached. This feature can save on running costs, so it’s recommended to find a model which has it available.

4) Drainage tank

The drainage tank is where all the extracted moisture from the air will end up. For domestic dehumidifiers in the UK, the typical tank size is 1.5 litres – 2 litres. The bigger the tank, the less frequently you will have to empty it. Generally, the more powerful dehumidifiers will come with bigger tanks, as they’re able to extract more moisture from the air.

We recommend that you buy an dehumidifier that automatically stops working when the tank is full, so there are no spillages or small floods. It’s also useful to get one where the tank can be easily removed to avoid water spillages.

4 thoughts on “Using a Dehumidifier to Remove & Prevent Mould

  1. Susan

    I was using 70 pint Dehumidifer for my 2500+ sq. ft. basement, look like I need stronger one, do you have any recommendations? Should I replace with Commercial Dehumidifier?

    Reply
  2. Patrick

    Great article! I’m also a fan of desiccant dehumidifiers – although refrigerant models have their advantages. In the UK, condensation is always worse in the winter, which is also the type of climate desiccant models shine.

    Reply

Leave a Reply

Your email address will not be published. Required fields are marked *