Dehumidifier for cold rooms

Dehumidifiers for cold rooms: How to protect your valuables from the cold and damp

Update: 7 November 2025

Reading time: 4 min 

Dehumidifiers for cold rooms - compression or adsorption dehumidifiers?

In general, compression dehumidifiers are the most efficient. BUT an adsorption dehumidifier is recommended for temperatures below 10 °C.

• Compression dehumidifiers consume less electricity and have a higher dehumidification performance at temperatures above 15 °C. Especially if you want to use the dehumidifier in summer, you should consider buying a compression dehumidifier.

However,if the temperature in the room in which you want to use a dehumidifier is regularly below 10 °C (e.g. in a garage during the winter months), adsorption is the most suitable technology.

Dehumidifier and energy consumption

👉 In most households, the electricity costs for a dehumidifier are moderate - especially compared to the potential costs of mould damage or poor air quality.
For comparison:
- 🧊 Refrigerator: ~150-400 W
- Washing machine (in operation): 500-2000 W (peak values during heating cycles)
- 🔥 Iron: 1000-2000 W

Our models have a built-in hygrostat that only switches them on when required (similar to a thermostat).
It is also important to position the dehumidifier correctly to maximise airflow.

But let's take a look at the risks.

The silent danger: high humidity and mould Mould

In unheated areas, especially basements and garages, humidity levels often fluctuate greatly. When cold surfaces meet moist air, condensation forms, creating an ideal breeding ground for biological growth.

The climate in the cellar in winter: What makes it so difficult

As cold air can absorb less moisture than warm air, even a small amount of water vapour can quickly drive up humidity levels. Add to this a lack of ventilation and persistent sources of moisture (such as drying laundry or easy penetration of moisture through the walls) and you have conditions in which condensation, musty odours and even mould can thrive.

The regulation of environmental conditions in a cellar during the cold season differs from that in summer.
- The temperature remains low, which increases the relative humidity even without new moisture.
- Ventilation is reduced - windows and vents remain closed so that moist air is trapped inside.
- Heating is limited, so condensation forms easily on cold surfaces.
- Sources of moisture continue to exist, whether through daily laundry or the building structure itself.

Textiles and paper goods

Do you store old clothes or photos in your loft or cellar? Items made of natural fibres, paper and cardboard are extremely susceptible to moisture:
- Clothing and bedding: stored seasonal clothing, blankets and even boxes full of Christmas decorations can quickly develop mould and mildew. This not only causes musty odours, but can also lead to permanent stains and damage to the fabric.
- Documents, books and photos: Important documents, family photo albums and beloved books can become warped, sticky and irreparably damaged by mould spores. The resulting damage is often irreparable.
The solution: A high-quality dehumidifier is indispensable in damp storage rooms. By keeping the relative humidity (RH) constantly below 60%, you effectively prevent the conditions required for mould and mildew growth.

The garage dilemma: moisture and the high cost of Rust 🚗

For many of us, the garage is not just a place to park, but also a workshop, a gym or a place to store valuable equipment such as classic cars, motorbikes, high-end bicycles and precision tools. Yet garages are often the most neglected storage spaces in terms of climate control - and pay the highest price for it.

The silent danger for metal: condensation corrosion

Garages in winter

The greatest danger in an unheated garage in autumn and winter is Condensation.

Here's how it works:
1. cold surfaces: Metal objects (tools, vehicle bodies, engine blocks, chrome) get colder than the air.
2. moist air: When warmer, moisture-laden air hits these cold metal surfaces, the moisture immediately turns to liquid - this is condensation or "sweating" of the metal.
3. accelerated rust formation: This layer of moisture, combined with any salts or chemicals present, creates the perfect breeding ground for corrosion and rust.

This process not only damages the appearance. It also impairs the function and longevity of:
- classic cars: Rust attacks chassis, wheel arches and expensive chrome finishes.
- Precision tools: Rust impairs the sharpness of cutting tools and causes moving parts of power tools to jam or malfunction.
- Sports equipment: Metal parts on bicycles, golf clubs and fitness equipment can weaken and corrode.

The solution: regulate the air, not just the temperature

Whilst heating the garage can be helpful (e.g. with WDH-BGP02), without adequate humidity control, the risk of condensation can increase if too much warm air is supplied too quickly.
The most effective protection against corrosion in the garage is a two-pronged approach:
1. Moisture managementuse a robust dehumidifier that is suitable for your garage. Maintaining a relative humidity (RH) of around 50% is crucial to prevent rusting.
2. Temperature stabilisationuse a controlled heater to prevent extreme temperature drops, which slows down the condensation cycle and allows the dehumidifier to work more efficiently.
Don't let your valuable possessions fall victim to winter humidity. Protecting the air quality in your garage is the best investment you can make to preserve the value and condition of your metal items.

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