Air-drying clothes can be difficult if you live in a humid environment. The closer we get to air saturation (100% humidity), the harder it is to dry clothes.
In some places in the world (the UK, for example), 90% humidity is common. But this leads us to ask, will clothes dry in 90% humidity? And can we do anything to help speed up the process?
Will Clothes Dry in 90% Humidity?
Clothes will absolutely dry in 90% humidity. In fact, you can dry clothes indoors when the outside relative humidity is 100% humidity, as the air indoors will be less humid than this.
While there’s no set time for how long clothes will take to dry at 90% humidity, it unsurprisingly takes much longer than at lower humidity levels.
To understand air-drying clothes in a bit more detail, we need to explain a bit of the science. It’s not necessary to delve too deeply into it, but some basic concepts worth knowing are:
- Relative humidity. This refers to how much water vapour air holds relative to its temperature. Warm air can hold more moisture than cool air, so as air heats up its relative humidity drops.
- Saturation point. This is the point at which the air can’t hold any more moisture, causing it to condense on surfaces until an equilibrium is reached.
In short, we can use these concepts to understand how to dry clothes at higher humidity levels.
Anything above 70% can be considered high humidity, at which point we should use some of the methods suggested below.
How Do You Dry Clothes in a Humid Environment?
To dry clothes, we need to cause the moisture to evaporate. Here are a few ways to dry clothes when relative humidity is high.
1. Dry indoors with windows open
If it’s really humid outside, it’ll be better to dry your clothes indoors. The maximum humidity indoors is around 60%, although 40-50% is most common.
Opening a window and the door of your drying room will help create a draft.
You could also try using a fan. While it won’t bring the humidity down, it’ll help create airflow.
However, these options aren’t very efficient because you’re not doing anything to remove humidity from the air.
The most important thing when drying clothes is to remove moisture from them (and the surrounding air). A draft can help with this, but it’s not the best option.
2. Dry indoors with a dehumidifier
The best option for drying clothes indoors is to use a dehumidifier. Removing any level of moisture from the air will help, as this is more efficient than leaving a breeze to do it.
To make sure the dehumidifier doesn’t overwork itself, you’ll need to shut the windows and doors to create a more sealed environment.
Of course, the more humid your home is, the more often you’ll have to empty your dehumidifier.
A dehumidifier will also help you combat problems associated with damp. It’s more common in colder weather, but if the room’s walls are cold enough, water will condense on them. If there’s also no air circulation, you’ll end up with damp and mould.
3. Drying outdoors
Drying outdoors in 90% humidity will take a long time, but it is still possible. We can’t use a dehumidifier efficiently outdoors, so we have less control over the humidity in our drying environment. That said, several factors can help when drying outdoors.
The first is wind. Even a light breeze will help moisture to evaporate, and the chances of there being no breeze at all are fairly low.
Sunlight helps dry clothes faster because its energy causes water to evaporate. If it’s warm outdoors, even better, but this is perhaps the least important metric when it comes to drying clothes. Just make sure everything is spaced well apart and ideally isn’t folded over too much.
Drying clothes at 90% humidity is possible, but you’ll want to do everything you can to help speed up evaporation. This usually means improving airflow, which thankfully isn’t too difficult. Just try to have your clothes dry within a day otherwise they’ll start to smell musty.
Jacob is a freelance writer based in Wales, where he lives with his partner and two dogs. All his work is fuelled by extensive research and buckets of coffee.