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How to Kill Mould

Dehumidifier For Mould

Mould, especially black mould can be extremely bad for your health. The spread of mould inside your home can cause mild to severe allergic reactions, such as sneezing, runny eyes, itching and breathing difficulty. As mould grows it releases spores into your air which is harmful when inhaled. 

Mould can be especially dangerous for people suffering respiratory problems such as asthma or emphysema. Exposure to mould spores can trigger asthma attacks so it it is important to eradicate mould growth as soon as possible.

So how can you get rid of mould and can you prevent mould growth using a dehumidifier? We answer these questions as well as discuss other treatment methods in this article.

If you’re interested in learning more about the use of dehumidifiers in controlling mould growth, continue reading!

Do Dehumidifiers Kill Mould?

The short answer is no, a dehumidifier isn’t capable of killing existing mould or removing the patches of fungus from your walls or ceiling.

But what a dehumidifier will do to mould is inhibit it from growing. Mould grows anywhere that there is dampness or excess moisture. By removing that moisture you deprive mould of it's natural environment, so it can no longer grow. 

If you have existing mould in your home you will need to treat it with mould cleaning products to remove it from your walls or ceiling. In some cases where mould is in abundance a professional cleaning service may be needed to get on top of the existing mould.

Once you have removed the mould, your dehumidifier will ensure that it doesn't come back.

How to Choose the Best Dehumidifier for Mould

There are a few to things to consider when choosing a dehumidifier for mould. Firstly what type of dehumidifier do you need, a Desiccant or Compressor unit? 

If your space is heated or you live in a warmer part of Australia then the best choice is to use a compressor dehumidifier. If the room you plan on using it in regularly drops below 15C then you should consider using a desiccant dehumidifier. as they work much in colder temperatures. 

The next thing is to make sure that the dehumidifier you are considering purchasing is suitable for the size of your room. You can see the recommended room size for all of our units in the product page specification section.

To learn more about dehumidifiers, read our dehumidifiers buyers guide here.

We highly recommend the Ausclimate range of dehumidifers as they are specifically designed for Australian conditions. You can view the full range of Asuclimate dehumidifiers here

How to Eradicate Mould From Your Home

The first thing you need to do is bring down the humidity levels around your home. Mould needs humidity of around 55% or higher to grow, so bringing the relative humidity of your home down to 50% is ideal to stop mould from growing.

50% is also the optimal level for humans, so achieving this level will not only stop your mould growth but will also make your home the prefect humidity level for optimal comfort.

By investing in a quality dehumidifier you can quickly remove the excess moisture in your home and easily maintain a relative humidly of 50%. While dehumidifiers can reduce the humidity levels down to 30% or lower, it is important to aim for the optimal 50% humidity level.

When you drop your humidity level below 50% you might experience some adverse effects. These can include dry lips, dry eyes, sore throat or dry skin. So once you have removed the excess moisture set your machine to 50% and it will automatically monitor your air and maintain the 50% humidity level.

While using a dehumidifier is the best way to stop mould growth, there are other things you can do to try and stop it from growing.

  • Support proper ventilation in the areas that tend to be warmer most of the time, such as bathrooms, kitchens and laundries.
  • Open your windows to let in fresh dry air when possible to creat air flow through your home. 
  • During winter, start raising the temperatures gradually rather than suddenly, as the sudden gush of warm air can cause a spout of growth for dormant mould spores.
  • Use fans to help circulate the air more efficiently.
  • Check and fix any leaks in your roof that could be slowly building up excess moisture in your ceiling and walls.
  • Try to stop rainwater from pooling near your external walls by installing drains to remove the excess water.

How to Deal With Mould Yourself

There are many store bought products that work very well to remove mould. Most of these products contain bleach which kills mould on contact. It is important to note that these chemicals can be quite strong, so protective clothing such as gloves and masks are recommended when using store bought products.

Alternatively you can make your own solution that you can use to kill mould. There are many recopies that you can find on the internet that work well. We have a few listed below.

White vinegar - Pour undiluted white vinegar into a spray bottle and simply spray the mould and wipe with a damp cloth. Repeat until the mould has been removed.

Bicarb Soda - Mix a quarter of a tablespoon Of bicarb in spary bottle filled with water. Shake until the bicarb has dissolved. Spray the effected area and scrub gently, then wipe with a sponge or damp cloth.

Hydrogen Peroxide - In a spray bottle make up a 3% solution of hydrogen peroxide with water. Spray the effected area and leave it on for 10 minutes. Next scrub the effected area gently to remove the mould then wipe clean with a sponge or damp cloth.

It is always recommended to do a small test patch in an area that won't be easily seen to ensure no discoloration will occur.

If you have very large patches of mould then we strongly suggest to contact a professional mould cleaning company, as they will be able to kill and remove the mould safely.


To recap, dehumidifiers aren’t capable of killing pre-existing mould or mildew spores. What they do is deprive the spores of their optimal environment to thrive. As a result, mould is not able to grow.

The best thing to do is to firstly kill the mould so it isn't a health issue for you or your family and then to use your dehumidifier to stop it from returning.

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