Dehumidifiers buying guide
Last updated: March 7, 2024
What is a dehumidifier?
A dehumidifier is designed to regulate relative humidity levels by drawing in air, extracting moisture, and releasing the conditioned air back into the environment. The extracted moisture collects in a tank, which can be easily emptied. Besides keeping a room dry and comfortable, a dehumidifier also contributes to better indoor air quality, making it an excellent investment for anyone who wants to maintain a healthy living or working environment.
In this article we’ll explain everything you need to know about dehumidifiers and how they can help you maintain a healthy living environment in your home. If you often dry laundry indoors (let's face it, when the weather isn't cooperating and tumble dryer costs are soaring, who doesn't?) or are struggling with damp, humid conditions, then a dehumidifier will be an essential piece of kit!
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Keep reading as we demystify the key differences of home dehumidifiers available (ie. compressor and desiccant), as well as important features to consider when making a purchase.
Do I need a dehumidifier?
We often overlook the air quality within our homes, failing to recognise the significant levels of humidity present. Humidity can arise from various sources, including drying laundry and boiling food. Even hot, steamy showers and living in a rainy country can contribute to the issue. As humidity levels increase, condensation may appear on windows or walls. You might also notice musty smells in the air. Dehumidifiers help with effectively managing and reducing excess humidity in your home.
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These handy appliances remove moisture from the air, which can help prevent the growth of mould and reduce allergens like dust mites. Did you know that dust mites cannot survive when humidity is below 50%? So, keeping the humidity level low in areas like bedrooms can help prevent them from multiplying, especially useful for areas such as bedrooms.
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Not only that, but a dehumidifier can help protect your home and belongings from damage caused by excess humidity. If you notice wallpaper peeling or mould growing on walls or soft furnishings, it's a clear sign that your humidity levels are imbalanced. Investing in a dehumidifier can assist in rectifying this issue and maintaining a healthier environment.
How does a compressor dehumidifier work?
Compressor dehumidifiers, also known as refrigerant dehumidifiers, work by drawing humid air over a refrigerated coil with a fan. The cold coil condenses the moisture in the air, turning it into water that is collected in a tank. This process works the best in warmer climates above 10-15°C.
How does a desiccant dehumidifier work?
On the other hand, a desiccant dehumidifier uses a desiccant material which is a substance that naturally absorbs moisture. This type of dehumidifier is especially effective in colder climates or lower temperatures under 20°C, such as caravans or cellars, where compressor dehumidifiers are less efficient.
Compressor dehumidifiers vs. Desiccant dehumidifier
What size dehumidifier should I buy?
Take a look at the dehumidifier sizing chart below. The answer hinges on two key factors: the size of your house or room, and the amount of moisture generated by your home environment. The bigger the home or room you want to dehumidify, the more powerful you will need your machine to be. The tasks you regularly perform at home will influence your choice of dehumidifier. While most dehumidifiers can handle the moisture generated by cooking and showering, you might require a more robust unit if you have a lot of house plants, dry laundry inside regularly, have a cold cellar or live in a wet or humid country.
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The situations above all create more moisture within a home, especially drying laundry. Many dehumidifiers have laundry modes to help with extra moisture when drying clothes. If you do laundry indoors often, this type of dehumidifier may be beneficial for you.
Dehumidifier sizing chart
Where should I place my dehumidifier?
There’s no single rule for the best placement – it depends on your situation. Here are the four most important considerations:
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1.) Place the dehumidifier close to the primary moisture source.
Think about where the humidity in your home is likely to be coming from. Do you often have long showers? If so, the bathroom is likely to be a major source of moisture, so you should place the dehumidifier nearby (but not in the bathroom as dehumidifiers are not waterproof). Do you cook a lot of meals on the hob? In this case, the kitchen may be where a lot of the moisture is coming from. Other common sources include basements, drying laundry, and open windows. Alternatively, place the dehumidifier in the room with the worst condensation.
2.) Always allow enough space for plenty of airflow. Dehumidifiers need consistent airflow to function effectively. Most people don’t want their dehumidifier in full view, but it’s important that air can circulate around the machine. For this reason, avoid placing the dehumidifier against a wall, in a corner, tucked against furniture, or pushed up against curtains. Leave at least 30cm between an object and the dehumidifier, although some models require more (check the manual).
3.) Consider the size of the room. Most dehumidifiers can quickly reduce the humidity in a small room regardless of where they are placed. But for bigger rooms, a dehumidifier will be most effective in a central location. If you want to dehumidify multiple rooms, consider placing the machine in a hallway – and make sure you buy a model with a large extraction capacity.
4.) Consider the type of dehumidifier you have. Refrigerant dehumidifiers are the most common type in the UK, as they work best in warm environments. Desiccant dehumidifiers are less popular, but are better suited to cooler locations, such as unheated garages or conservatories. If you have a refrigerant dehumidifier, make sure you place it in a heated room to ensure it’s effective.
Tip: Another consideration is whether you want to use a continuous drainage hose. To use this function, the dehumidifier will need to be placed near a floor-level drain.
Can you place a dehumidifier anywhere?
Having a dehumidifier anywhere in your home is better than nothing. Reducing the humidity in one room causes moisture to spread out from elsewhere in the house, which can lower the overall humidity. In fact, in smaller homes, a single dehumidifier placed in a hallway could eventually reduce the humidity in every room.
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Just placing the dehumidifier in a random location isn’t the best way to reduce the humidity in your home though. Instead, it’s important to place the machine near the primary source of humidity, so it can extract moisture efficiently before it spreads to other parts of the home.
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Once you’ve got the moisture under control in the worst room, you could consider moving the dehumidifier to a more central location in the house.
Stop putting up with damp and mould in your house
Using a dehumidifier in your home can really make a difference to your air quality and any humidity problems you may be having. By effectively drawing out the excess moisture from the environment, it will help you to dry laundry quicker and prevent mould from forming on walls. Whether you're dealing with varying temperatures or specific needs, there's a dehumidifier that's perfect for you.
Don't tolerate the damaging effects of high humidity levels any longer, bring a dehumidifier into your home and experience the noticeable difference it can make.
Features to look out for when choosing a dehumidifier
Laundry mode
Laundry Mode is a special function designed to help with indoor laundry drying. When activated, the dehumidifier works at a high capacity to extract excess moisture from the air, accelerating the drying process of wet clothes.
FAQs | Here are some frequently asked questions
What is relative humidity?
Relative humidity is a measure of how much water is in the air relative to the amount that air could hold if it was saturated. Relative humidity is expressed as a percentage. When relative humidity reaches 100% it is at the "dew point". In other words the air is "full" of water and that water will start to condense onto any surface.
Warm air holds more water than cool air so as air cools relative humidity rises even though the physical quantity remains constant.
For every fall in temperature of 20°F or 10°C the capacity of the air to hold water is halved. For example air at 80°F with a relative humidity of 50% will reach the dew point, 100% RH when it has cooled to 60°F.
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Where does the water come from?
Water is always in the air, inside and outside the home. The amount inside the home varies and is increased by many routine daily life activities such as cooking, washing, showering, making tea and breathing. If you have uncovered water containers in the home like fish tanks etc., then these will also add to the amount of water in the air.
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What is the ideal humidity level for my home?
Generally a relative humidity of 50% is comfortable for your home. This will protect your home and belongings, prevent mold growth and control the dust mite population. There is no real need to reduce humidity below the 45-50% mark. To do so will simply cost more in energy while serving no useful purpose.
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How long will it take to get the moisture under control?
As long as the dehumidifier you choose is large enough for the area it is working in, and there are no specific damp problems, then a dehumidifier will normally reduce the humidity to the chosen level within a few days to a week. This timescale does not apply if the room has been flooded, in which case one or more dehumidifiers will be needed and possibly supplemented by air movers and other specialist equipment. This work is usually undertaken by specialised water damage specialists.
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How much water does a dehumidifier remove?
The answer to this depends on three specific factors. The power of the dehumidifier, the room temperature and also the relative humidity of the air in that room. A 12 litre dehumidifier will rarely, if ever, remove 12 litres in a single 24 hour period. Once relative humidity has been reduced to your chosen level the dehumidifier should only be operating intermittently to maintain that level so the amount of water collected in the bucket will be lower still.
As a general rule of thumb you may need to empty your dehumidifiers bucket at intervals ranging from once every two days to twice a day, depending on the conditions. It is only in exceptional circumstances that a properly sized dehumidifier will need emptying more frequently than this, unless of course you have placed it in a very damp room for the first time.
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Can I use the water that collects in the bucket?
The water collected in the dehumidifiers tank is called condensate, you can use this in your iron or to water the plants! However, it should not be drunk by humans or animals as it may contain traces of substances that could make you, your pets ill.
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How does a dehumidifier prevent mold and mildew?
A dehumidifier prevents mould and mildew growth in two ways. First it dries out the room, drawing damp from the contents and fabric of the room on which mould and mildew will inevitably form and prevents that damp from recurring. Secondly, providing the dehumidifier is set to maintain relative humidity at 50% or slightly below, the air is too dry for mold and mildew spores to develop. Fungi need airborne water as well as surface water to grow!
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Where is the best place to site my dehumidifier?
In an ideal world a dehumidifier would be silent and invisible. The next best thing is to be out of sight and earshot. Unfortunately the first is impossible and the second, while achievable in some cases, be more expensive in cost and effort. If you need to lower humidity throughout your house a whole-house dehumidifier is the best option. It is easy to fit, virtually silent and is the cheapest solution for whole house control. If you are using a portable dehumidifier in a small to medium sized room, a laundry room or a bedroom for example, it is not particularly important where you position it.
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What is continuous drainage?
All portable dehumidifiers have a water collection container, often called a tank or a bucket, to collect the water extracted from the air. These buckets are quite small, to keep the overall size of the dehumidifier down, and need to be emptied at least once a day. Because it may not be convenient, or possible, to empty the bucket daily almost all portable dehumidifiers for home use are designed to allow the water to be drained directly as it is collected. This is known as continuous drainage.
In the casing of the dehumidifier a small hole has been cut to allow a small hose ( most of our units come with this hose in the box ) to be attached to the dehumidifier through which the water can be drained. The water is drained by gravity alone so for effective continuous drainage the dehumidifier needs to be raised a foot or two above the floor and the hose run to a floor level drain.
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Do dehumidifiers need to be in the middle of the room?
It’s true that dehumidifiers are most effective when they are placed in the centre of the room. A central location often provides maximum airflow and allows the dehumidifier to pull in moisture from the entire room. With that said, leaving a dehumidifier in the middle of the room often isn’t practical. Aside from taking up a lot of space, most dehumidifiers aren’t designed to be decorative items!
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A good compromise is to put the dehumidifier in a spot where it’s at least 30cm away from a wall, furniture, or any other object. It won’t be quite as effective as if it was in the centre of the room, but the machine will still have enough airflow to lower the humidity in the room.
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Can you sleep in a room with a dehumidifier?
There’s nothing dangerous about sleeping with a dehumidifier. In fact, bedroom windows are often affected by condensation, making this room a good choice to dehumidify. However, the noise produced by the dehumidifier may keep you up, so it’s important to look for a quiet model. Keep in mind that many dehumidifiers will switch on and off during the night, as they have a built-in humidistat to target a relative humidity level.
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Can you put a dehumidifier in a corner?
We don’t recommend placing a dehumidifier in a corner, as it won’t be able to function effectively. Being close to two walls reduces the amount of airflow around the machine and limits the amount of moisture it can pull from the air.
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Summary
Dehumidifiers don’t need a perfect placement to reduce humidity, but you should still think about where the machine will be most effective. Ideally, the dehumidifier should be placed near the primary source of moisture. It’s also vital that there is enough space for air to flow all around the dehumidifier.
We hope this article has helped clarify where to place your dehumidifier. If you have any questions, please contact our friendly customer support team who will assist you.
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How to contact us
Our friendly customer support team are happy to assist you Monday - Friday | 8:00am - 5:00pm.
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Live chat support: Speak to our livechat team
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Email: support@shuddle.co.uk
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Telephone: 01234 567 890
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(Current call wait time: Less than 3 minutes | Emails typically replied to within 24 hours of receipt)
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