A Guide to Boat Dehumidifiers

A Guide to Boat Dehumidifiers

Our Best Selling Boat Dehumidifiers with Free UK Mainland Delivery


It’s always a good time to consider how best to keep the interior of a boat or yacht free from damp and mould over the winter months during end-of-season lay-up.

At Dehumidifiersuk we are avid maritime fans and always advise our customers to always use a dehumidifier on a boat.

Once of the most common problems we hear occurs during the winter months when the temperature drops significantly. Mould will grow in damp conditions where the relative humidity (RH) is greater than 60%. Iron will rust with humidity above 50% and steel above 80%, so it is around the winter months that engines and tools become vulnerable to the moisture in the air.

Dehumdifiersuk recommend dehumidifiers suitable for boats and caravans, in particular desiccant dehumidifiers. What theese units have in common is that they are compact and work well as the air is drawn in through a filter and passes over a slowly rotating wheel that is coated with a material called zeolite, which absorbs water from the air.

Desiccant dehumidifiers thrive on cold air temperature and also heat the space in which they are removing the moisture. This will gently warm the boat’s interior and help to prevent the domestic fresh water pipes freezing up. Desiccant dehumidifiers are also much lighter in weight than compressor models.

What to look for:

You can buy basic or sophisticated models of dehumidifier. Basic models will have a humidistat: this will switch the machine off when the humidity drops to a pre-set percentage. Though variable, you don’t really know what value this is. On sophisticated models you can set it, although they switch off anyway when the humidity is reduced to around 50%. All models collect the water in a container (the bucket). For some this is a translucent tank which enables you to see how much water has been collected. All have a cut-off switch that shuts the machine down when the tank is full, and a ‘full tank’ warning light.

Also, they can all be put in continuous drain mode, which bypasses the collection bucket and involves fitting a piece of tubing onto a spigot and directing the water into, for example, a sink drain. All dehumidifiers will have an inlet air filter. These vary in quality, and some can be enhanced with carbon to neutralise odours or a biological element such as silver ion to kill microbes. The simple mesh filters can be cleaned using a vacuum cleaner soft brush attachment.

Some carry handles can be folded out, while others are fixed recesses in the machine’s body. These fixed indents are not so handy if the unit needs two hands to lift it. Some machines have a laundry mode which puts them on optimum performance, and in some cases enables the warm outlet air to be directed towards damp hanging clothes, assisting their drying. A timer may be present that will allow you to set how long you want the machine to work.

Another ‘extra’ is an ioniser. This delivers negative ions into the air that attach themselves to positive ions – fine dust particles, for example – making them heavy, so they fall to the floor where they can be vacuumed up.

Think Boat - Think Desiccant:

A desiccant boat dehumidifier will function at temperatures as low as one degree centigrade. A compressor-driven dehumidifier works best when the temperature is at or above fifteen degrees centigrade. If you intend to leave your boat dehumidifier unattended during chilly winter months, a desiccant unit is just the thing you want. Be sure to use a boat dehumidifier that comes with an automatic restart feature, in case the electricity is ever interrupted.

A continuous drainage facility is another important feature to look for. As you will not be there to drain a reservoir every day, continuous drainage will send the extracted moisture away from your dehumidifier unit.

If the inside of your boat becomes too damp, it will not be a pleasant environment for anyone. Mould and mildew may grow, and once they have taken hold, they are difficult to remove. If you do find signs of mold and mildew, clean every bit of it up just as soon as you can. Use a diluted chlorine bleach solution to scrub away all indications of mold growth. Dry the area thoroughly. A disinfectant spray such as Lysol may inhibit regrowth, but you must make certain that the relative humidity level stays where it belongs. Relative humidity in excess of fifty-five percent can signal trouble.

How Dehumidifiersuk Can Help:

In addition to an excellent boat dehumidifier, we sell domestic dehumidifiers, extractor fans and air purifiers for residential and commercial applications. If you would like to know more about any of our world-class air products, please send your query to us at sales@dehumidifiersuk.com.