Common Questions

What is “humidity”?

Humidity refers to the amount of water vapour in the air. The ‘humidity’ we hear referred to most commonly in relation to weather, is referring to relative humidity.

Relative humidity is expressed as a percentage relative to the maximum and depends on both temperature and pressure. Weather forecasters will often use this to determine the likelihood of rain. A rise in relative humidity in summer can increase the temperature we feel by slowing down how fast our perspiration evaporates from our skin. It is the same case with moisture contained in curtains, carpets and furnishings.

What humidity range is recommended for my home?

It is recommended that you keep your home below 60% relative humidity. Mould requires a relative humidity level of 65% - 70% grow.

Will a dehumidifier remove the same amount of moisture in all room temperatures?

A dehumidifier's ability to remove moisture is dependent firstly on the amount of moisture in the air. If dehumidification has reduced the humidity to a low level, less moisture can be removed from the air. It is also more difficult to remove moisture from cold air than warm air.

Mitsubishi Electric Oasis dehumidifiers are fitted with a hot gas defrost system which allows them to continue removing moisture even when the room temperature drops as low as 1°C. This is the lowest operation range on the New Zealand market.

I have just started using my new dehumidifier, why is there still condensation on the windows in the mornings?

  1. It will take few weeks of your dehumidifier running constantly to reduce the built up moisture in your home to an acceptable level. We recommend setting the unit to high and running it for 24 hours for a few weeks, moving it from room to room. After a few weeks the unit can then be set to one of the auto modes (ideally under 60%). This will help you maintain a healthy humidity level.
  2. On cold mornings there often is a small amount of condensation on the windows but this will evaporate quickly.
  3. On cold nights it is important to have the dehumidifier running whilst the house is warm - this will result in more moisture being removed than if you start the dehumidifier before you go to bed, and will result in less condensation forming on the windows.

Can I leave my Mitsubishi Electric Dehumidifier turned on 24 hours a day?

The unit can be left running unattended. It will switch off automatically when the tank gets full or the required humidity is reached. If you are looking to leave your dehumidifier on for a long period of time, all our dehumidifiers offer a permanent drainage option. This allows you to bypass the drainage tank, using a hose to remove the water collected.

Why does the noise level fluctuate?

During operation the compressor in the unit will turn on and off. This will be signalled by an increase in volume.

Why does the defrost lamp light up and the fan stop?

When the room temperature falls below 15°C, your dehumidifier may go into defrost mode. Defrost mode will occur approximately every half an hour, and will last for a few minutes. During defrost mode the fan will stop but the compressor will keep going.

Can I drink the water collected in the tank?

Please do not drink this water as dust and other impurities can collect in the tank. If you are looking to recycle this water, it can be used in your wastewater tank or for watering houseplants.

My Mitsubishi Electric dehumidifier is noisy - is it faulty?

It is important to remember that all dehumidifiers make some noise due to the operation of the compressor and fans. Mitsubishi Electric Oasis dehumidifiers are in fact the quietest products available in NZ. However, they do still make a noise. Noise levels are dependent on many factors. Place the unit on a firm, level surface. A unit placed on a wooden floor will make more noise than a unit on carpet.

Damage during transportation in our experience is the most common reason for excessive noise - it is important that your dehumidifier be handled carefully during transportation and should always be transported upright. If you think there is an issue with your dehumidifier, please do not hesitate to contact our Customer Support team.


Common questions