Dehumidifiers are relatively cheap to run, easy to use, and can save you a lot of discomfort. Throughout the year, a dehumidifier can tackle mould and damp by ridding the air in your home of excess humidity. To help you pick the best dehumidifier for your needs, just consult Canstar’s buying guide:
What is a dehumidifier?
A dehumidifier is a household appliance that, as the name suggests, reduces the level of humidity in the air. Usually used for health and comfort purposes, a dehumidifier extracts water from the air inside your home.
How do dehumidifiers work?
Dehumidifiers work in two ways – refrigeration and absorption. Each is suited to a different environment.
Refrigeration (or compressor) dehumidifiers draw in air through a filter and over cold coils. Most home dehumidifiers use this method. They work like this:
- Moist air is sucked into the dehumidifier
- The humid air passes over pipes chilled by a coolant.
- As the air cools, the moisture condenses onto the pipes, and drips into a collection vessel
- The moisture-free air passes over a heating element and is blown back into the room
These are the most common types of dehumidifiers. It’s claimed they work better in higher temperatures and at increased humidity levels.
Also known as desiccant dehumidifiers, they use an absorbent material to extract water from the air. They work like this:
- Moist air is drawn into the dehumidifier
- The humid air moves over a rotating wheel made of a water-absorbing material
- The dry air is blown back into the room
- The water-absorbing material is heated, causing it to release its water into a collection tray
Absorption models are more complicated in their design and can be less energy efficient. However, absorption dehumidifiers work better at lower temperatures, which make them a good option for use in colder climates.
Features to look for
A decent humidifier costs from around $350 to over $1000. A general rule of thumb is the more you spend the more efficient the machine at removing water from the air. However, you also need to gauge your needs and the features you require.
- Size: Smaller dehumidifiers are more portable, but have smaller water tanks. This means they need to be emptied more frequently.
- Hose connection: If you don’t want to bother emptying the water tray constantly, you might want to consider a continuous drainage option like a hose connection. A hose connection lets you divert the water directly to the drain.
- Noise: As most compressor dehumidifiers work in the same way as a fridge, they produce similar amounts of noise. Then there is additional noise from fans. Before making a purchase, listen to your choice of machine in action, to gauge whether you’re happy with its quietness.
- User-friendly controls: As you might expect, more expensive models have a higher degree of flexibility when it comes to their controls. All controls should be easy to understand and use. Two of the most common features are timers and humidistats, which we explain below.
- Auto on-off: Some units will automatically turn off once your desired humidity level is reached, then turn back on if it rises again – saving you power.
- Washable air-filter: More expensive models have washable air filters similar to those in air purifiers. These filters capture airborne contaminants. Having one that’s washable can prolong the lifespan of your unit and maintain its effectiveness.
- Humidistat: This allows you to target a relative humidity level for your room. Depending on the model you buy, this can either be precise or just a basic setting, like low to high. The ideal relative humidity for a home is about 50%, although anywhere between 40-60% is good. If your humidifier comes with this feature, experiment for a bit to see which humidity level feels the most comfortable for you.
- Auto-defrost and low temperature options: If you happen to live in a low-temperature area, an auto-defrost feature could be crucial. Anti-frost sensors turn off the dehumidifier if frost starts to form on the coils. This can be extremely helpful if you live in a climate that is regularly below 15C.
Some models to check out:
This Panasonic model can remove up to 17L of moisture per day and features a 4.8L water tank. Functions include, auto-dehumidify mode, laundry drying mode, and a programmable timer. There’s also a continuous drainage hose option.
This model is great for small- to medium-sized rooms. It has a 2L water tank, an adjustable humidistat, and an automatic shut-off setting.
This Mitsubishi dehumidifier has a 4L water tank and boasts anti-bacterial air filters. It has an easy-to-use control panel and seven drying modes, including laundry and an ultra-quiet low operation setting.
This desiccant dehumidifier has a 9L extraction rate per day and 5L water tank. It has washable HEPA 13 Filters to trap allergens, bacteria and viruses, a clothes drying function and a continuous drain option.
How much does a dehumidifier cost to run?
According to Trustpower, running a 300W dehumidifier for 10 hours a day will cost between 69c to $1.47.
Get a better power deal with Canstar
If you’re concerned about your power usage, consider whether you’re on the best deal for your household. Because you could be getting a better rate. Canstar rates electricity providers, so you can compare your options easily:
Canstar Blue’s latest review of NZ power companies compares them on customer satisfaction. The table below is an abridged version of our full results, available here.
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Canstar Blue NZ Research finalised in May 2020, published in June 2020.
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Tips for operating your dehumidifier
- Wash air filters once a month to help the fan operate efficiently.
- Keep an eye on temperatures. Most dehumidifiers operate less efficiently when the temperature falls below 18C.
- Maintain good air-flow. Keep your dehumidifier away from the wall for good air circulation.
If you’re looking into heating and moisture-removal options for winter, it’s a good time to check whether you’re getting the best rate for your electricity plan. Canstar compares electricity providers in NZ, so to check you’re on the best deal, just click the button below:
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