Best Dehumidifiers: The Definitive Guide to Buying a Dehumidifier for a New Zealand Home
Our guide explains everything you need to know to buy the right dehumidifier at the best price
Updated 16 November 2020
There are many options to fight high humidity in the house and minimize mould and dampness. Solutions include using a dehumidifier, growing plants, leaving open doors of rooms to allow good air circulation, taking regular cold showers, and even replacing carpets with wooden floors. Using a dehumidifier is a sustainable and the most reliable option, but deciding what model to buy is not as easy as it sounds.
Our guide gives an overview of the problem of high humidity and explains everything you need to know about buying a dehumidifier that best fits your needs.
Our Dehumidifier Buying Guide Covers:
Our guide gives an overview of the problem of high humidity and explains everything you need to know about buying a dehumidifier that best fits your needs.
Our Dehumidifier Buying Guide Covers:
Know this first - why are dehumidifiers necessary?
The effects of high humidity on health should not be taken lightly. Besides ruining walls and giving off a damp smell, if left unattended, humidity could potentially put your health at risk by causing dehydration, fatigue, poor sleep, muscle cramps, heat exhausting, and even fainting. If you or any member of your family suffer from asthma, allergies, or arthritis, the situation could be even worse.
Mould issues with houses are common all over New Zealand; this Stuff.co.nz article suggested 49% of homes are affected. Every house has a unique humidity situation - mouldy ceilings and rotten timbers are just some of the visible long-term damage caused by excess moisture. What dehumidifiers do to tackle this issue is pulling out dampness from the air, restoring indoor humidity levels to a healthier (and more comfortable) range. With less water in the air, there's less mould and healthier living conditions.
Mould issues with houses are common all over New Zealand; this Stuff.co.nz article suggested 49% of homes are affected. Every house has a unique humidity situation - mouldy ceilings and rotten timbers are just some of the visible long-term damage caused by excess moisture. What dehumidifiers do to tackle this issue is pulling out dampness from the air, restoring indoor humidity levels to a healthier (and more comfortable) range. With less water in the air, there's less mould and healthier living conditions.
What are the types of dehumidifier​, and how much do they cost?
Depending on the technology used to tackle dampness, dehumidifiers can be classified into one of the following categories:
Option One: Refrigerant Dehumidifiers (the most common in New Zealand homes)
This is the most common type of dehumidifier you will find in stores like Noel Leeming or Harvey Norman. The reason is simple; refrigerant dehumidifiers are cheaper and relatively easier to install than the rest. They work by condensing moisture from the air into cold metal plates, a principle similar to what happens when moisture droplets condense on a window surface when cold. To cool the metal plates, this type of dehumidifier uses a refrigerant circuit (thus its name) a technology not different from what is used in a fridge.
The main disadvantage associated with refrigerant dehumidifiers is that their efficiency in removing moisture is dramatically affected when the ambient temperature is below 15 ° C. Imagine using your fridge outside during the winter. Internal coils will freeze, and the unit will simply stop working. High-quality dehumidifiers solve this problem by heating the internal radiator as necessary; however, such a solution make these units more expensive.
Refrigerant Dehumidifiers Highlights
Pros:
Cons:
The main disadvantage associated with refrigerant dehumidifiers is that their efficiency in removing moisture is dramatically affected when the ambient temperature is below 15 ° C. Imagine using your fridge outside during the winter. Internal coils will freeze, and the unit will simply stop working. High-quality dehumidifiers solve this problem by heating the internal radiator as necessary; however, such a solution make these units more expensive.
Refrigerant Dehumidifiers Highlights
- They are cheap to manufacture since they use proven “heat pump” technology.
- Refrigerant dehumidifiers work by cooling a metal surface to condensate moisture present on the air.
- Unless they are equipped with defrosting features, this type of dehumidifier work best at room temperatures above 18°C.
Pros:
- Widely available, cheap, and practical.
- Easy to install and maintain due to their well-known refrigerant technology.
- Most models are portable, meaning you can use them as required in different areas.
Cons:
- They use a compressor, so you will be adding another power-hungry appliance to your electricity bill.
- Dehumidifiers capable of working at “low room temperatures” are more expensive due to additional components that prevent coils from freezing.
Option Two: Desiccant Dehumidifiers
Unlike refrigerant-based dehumidifiers, desiccant dehumidifiers use hydrophilic materials to collect moisture from the air. These materials are similar to the silica gel crystals used in the packaging of electronic components or the non-toxic silica gel used in cat litter. Desiccant dehumidifiers work by drawing air from the room and passing it through the desiccant material which is then heated to remove the collected moisture. While it is true that desiccant dehumidifiers do not have the same capacity as conventional refrigerant-based models, it is also true that they are a better option in certain situations. For instance, desiccant units maintain their efficiency at low temperatures which make them a good option for New Zealand winters. They are also smaller and quieter than compressor-based dehumidifiers, a great advantage if high noise levels are an issue for you.
Desiccant Dehumidifiers Highlights
Pros:
Cons:
Desiccant Dehumidifiers Highlights
- They do not use an internal compressor like conventional refrigerant units.
- They use a desiccant media to collect moisture from the air (hence its name).
- Desiccant units keep their efficiency at low room temperatures.
Pros:
- Smaller and quieter than compressor-based units.
- Good for regions like Auckland where low temperatures and high relative humidity may be a problem for conventional units.
- These units arguably deliver a more balanced indoor moisture level thanks to their operation mechanism.
Cons:
- Not as readily available as conventional dehumidifier units.
- Lower capacity than conventional compressor-based units.
- Modern refrigerant-based dehumidifiers are offering similar performance.
Option Three: ​Whole House Ventilation Dehumidifiers (least common in New Zealand homes)
Whole-house dehumidifiers are a special type of unit with enough capacity to extract moisture not just from one room, but from the entire house. These units are usually installed in parallel with the air conditioner ductwork, however, even without central air conditioning, they can be installed independently. This type of dehumidifier is perfect for families where one or more of its members suffer from asthma, allergies, or other respiratory problems. Whole-house dehumidifiers are also ideal if your basement is high in humidity. As you can imagine, a unit with the ability to extract moisture from such a large area is more expensive than smaller dehumidifiers. However, the higher upfront cost of whole-home dehumidifiers is compensated by its lower running costs as well as their greater reliability.
Whole-House Dehumidifiers Highlights
Pros:
Cons
Whole-House Dehumidifiers Highlights
- They have a higher capacity than any other type of dehumidifier.
- Ideal for getting rid of mould and mildew caused by high humidity levels.
- These units usually are installed in the basement along with central A/C appliances.
Pros:
- Since they are installed on the basement and use the same ductwork as central A/C they are completely silent.
- A good solution to tackle asthma, allergies, and other respiratory affections.
- They provide a balanced humidity level across the entire house.
- Lower running costs.
Cons
- They are more expensive than the smaller dehumidifier units.
- They require professional installation.
- Most units use 120VAC compressors.
How much does a dehumidifier cost to run?
According to Trustpower, running a 300W dehumidifier for 10 hours a day will cost between 63c and $1.42. Over a month, this will be about $19 to $45.
​Key Factors to Consider When Buying a Dehumidifier for Homes in New Zealand
Now that you have a better understanding of how dehumidifiers work, it's time to review what are the most important features to look for in the unit.
- Dehumidifier type. Refrigerant, desiccant, or whole-home; the type of dehumidifier will be determined by your budget and weather condition in your region.
- Dehumidifier capacity. Each home has unique humidity conditions. Our suggestion is to choose whole-home dehumidifiers for areas greater than 300 square meters (4+ bedroom house), a 22L/day unit for areas up to 280 square meters (3 bedroom house), a 17L unit for areas up to 220 square meters (2-3 bedroom house), and a 9L unit for areas up to 100 square meters (1-2 bedroom apartment).
- Water tank capacity. The larger the better for upkeep.
- Temperature range. Try choosing units with the lowest temperature range possible, especially if you live in the North Island.
- Continuous drainage. A desirable feature since you won’t have to drain the tank each time it fills up.
- Air filtration capability. A big plus for any unit since will prevent respiratory affections.
- Noise level. The quieter the better. Desiccant units tend to excel in this regard.
- Humidity control. A must-have feature nowadays. Humidity control lets you select the relative humidity percentage at which the unit will stop. Think of this feature as the thermostat in an A/C appliance
- Timer. An energy-saving feature that is strongly recommended
- Portability. Depending on your needs you may want a unit with casters for easy relocation on different rooms as necessary.
- Power consumption. As low as possible. Whole-house units excel in this regard.
- Price. Our suggestion is buying dehumidifiers “off-season” since you can save up to 25% off RRP.
Four of the Best Dehumidifiers Available in New Zealand Right Now
Choosing the best dehumidifier currently available in New Zealand is not an easy task. We have compiled our list (in no particular order) based on average consumer reviews collected from consumer-focused websites, technology publications and other sources, both in New Zealand and overseas.
No dehumidifier manufacturer has paid to appear on this list, and MoneyHub.co.nz has no relationship with any dehumidifier supplier or brand below.
No dehumidifier manufacturer has paid to appear on this list, and MoneyHub.co.nz has no relationship with any dehumidifier supplier or brand below.
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Getting the most out of your dehumidifier
A dehumidifier will give you the best results when the conditions are optimal. Our list below lists a number of tips to optimise the performance:
- Set the humidity level to a realistic number. The optimal humidity level is between 30 and 40 percent during the winter. If the level is set above 50 percent, mould, mildew and dampness will arise.
- Place the dehumidifier in the right spot. Even though most models release air from the top, the freeflow of air is essential. Place it where there are no air restrictions - while it may look unsightly and stick out, this will ensure it operates at its potential.
- Close all windows and doors, and restrict under-door drafts. You won't see results unless every outside door and window is closed - otherwise you're dehumidifying the great outdoors.
- Empty the tank regularly. You'll probably need to do this every day during winter. If you don't, it will stop working.
- Keep it clean. Follow the manual to ensure the filter is kept free of obstructions.
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