How to pick a dehumidifier

An ElectriQ 25l low-energy smart laundry dehumidifier, €255, buyitdirect.ie.

There are two types of dehumidifier: refrigerant dehumidifiers (also known as compressor type) and desiccant dehumidifiers. Refrigerant dehumidifiers are ideal for general, domestic use. Desiccant machines cost more to run but are suited to bigger jobs like drying out plaster in a new build.

A three-to-four bedroom house with condensation issues will demand an 18l model to extract 18l of water from the air. Smaller models in a large space may need emptying several times a day.

Typical functions would include continuous extraction, auto-shut-off, a boost function, and a sensor for humidity levels that can be set to 30%-80%. Sensors will keep the running costs down.

Dehumidifiers do have dust filters, but without a series of carbon filters, most do not operate as air purifiers (a different appliance that handles tiny particulate dust). Cheaper models will pull in and expel air, potentially raising finer dust.

Some better machines offer timers and boost functions to take in more water on drying day by, for instance, dropping the humidity from 40% to 35% for a period, with auto-shutoff to allow you to handle tank emptying more effectively.

The best place for your dehumidifier is somewhere central in the home, such as a hallway or a landing, according to B&Q which offers options with settings to help with particular tasks, such as drying laundry: "From this central location it will help control condensation and damp throughout the whole house.”

Keep in mind that although dehumidifiers draw moisture from the air, moisture that could lead to dust mites, fungi, mildew, and house moulds, they do not solve a serious, ongoing damp or condensation problem. They are best used as a short-term solution.