Relative humidity (RH) is how close the air is to being saturated with water vapour at its current temperature, given as a percentage. At 100% the air can hold no more, and water starts to condense. Because warmer air can hold more water vapour than cooler air, the same air shows a higher relative humidity as it cools, even though no water has been added.
At Wigwam
Our units are standard self storage: clean, dry and secure, with our indoor units purpose-built inside our buildings, out of the wind and rain. They aren’t climate-controlled, so the way you pack is what keeps humidity low around your things, and it’s simple to get right:
- pack everything clean and completely dry, because moisture you pack in raises the humidity inside a box or under a cover;
- keep things off the floor and leave a small gap at the walls, so air can carry moisture away;
- use breathable covers rather than sealed plastic for fabric, wood and mattresses;
- for a longer stay, add a few moisture absorbers, and keep a small battery hygrometer in the unit so you can check the reading when you visit.
At Chipping Norton and Shipston-on-Stour we insulate our container units to stop condensation.
Why it matters
For stored belongings, moisture matters far more than temperature. The Canadian Conservation Institute gives the practical boundary for damp as 75% RH, and notes that damp causes mould, which discolours or breaks down leather, textiles and paper. It adds that deterioration climbs rapidly as humidity rises, which is why a dry start and good airflow do so much.
Storing something especially sensitive to humidity, such as artwork or an instrument? Call us on 0800 2545585 and we’ll talk through the best way to store it.
Related terms
Related questions
- How do I stop clothes going musty in a storage unit?
- Do I need a dehumidifier in a container unit?
- Do storage units get cold in winter or hot in summer?
Further reading
- Met Office: Humidity
- Canadian Conservation Institute: Agent of deterioration: incorrect relative humidity