Dehumidifier Guide

I see that there are a lot of people asking about dehumidifiers not only on Boards but on other forums as well so I thought I'd be helpful and write a short dehumidifier guide.

Desiccant vs Compressor

There are basically two types of full size dehumidifiers. These are desiccant units and compressor units.

In Ireland (generally speaking) it is better to use desiccant dehumidifiers as these units are more efficient at temperatures below 20C.

Desiccant units also operate at lower temperatures than compressor units as the coils or rods in the compressor units can get too cold which affects the efficiency of the dehumidifier.

Most user guides of compressor dehumidifiers state that the unit will work down to temperatures of around 5C but in reality their function is really impacted at 10C or less (depending on the model of course).

Compressor units also release fluoro gases so they aren't environmentally friendly as such.

Due to their compressor parts compressor units are also noisier and heavier than desiccant units.

Water Tank

A typical domestic water tank holds around 2 litres of water though some tanks maybe slightly smaller (1.5L) or larger (3L).

Ensure that the water tank is located on the bottom of the unit and is easily accessible and not hidden behind the filter which you would have to remove first (in fairness only a few models are set up like this).

See if the tank has a lid to avoid spillage when removing a full tank and try to see if there are comfortable carry handles (the little things in life count).

If you are planning on running the dehumidifier continuously a continuous drainage option will make your life easier.

There are 2 types:

1) Gravity types which uses gravity to pull the water down. In this case the unit has to be located above the sink or drain.

2) Motorised types which can pull the water up into a drain or sink (of course these tend to break down more often)

Filter

Most dehumidifiers come with a standard dust filter which is fine for general use.

Make sure to clean the filter every 2-3 weeks for optimum efficiency of the unit (and lower running costs!!)

If you want cleaner air, or have people in the property who suffer from respiratory problems such as hay fever, asthma etc, then an anti-bacterial filter will help these people breathe easier.

Also an ioniser will really help these people as ionisers take positive ions such as dirt, pollen and mould spores etc, out of the air resulting in a better air for breathing.

Laundry Mode

If drying lcothes inside get a dehumidifier with a Laundry Mode function.

By drying clothes indoors you can elevate the relative humidity (RH) level by up to 30% causing a perfect breeding ground for Aspergillus Fumigatus spores which can cause severe, permanent respiratory problems.

A dehumidifier will of course keep the RH down thus ensuring that spores are kept at bay and that your walls and windows remain condensation free.

Other Features

Some other features that I would like to see are a digital LED screen which shows the humidity reading (otherwise purchase a very cheap damp meter or hygrometer as they are also known).

A timer function is also great as you can leave the dehumidifier running when you go to work or take the kids to school etc.

All dehumidifiers turn off when the water tank is full so there is no danger of spillage or leakage when you are away.

I'll add more later but now I have to put the kids to bed.

Feel free to pm with any questions etc.