Ways To Prevent Condensation In Tents

Ways To Prevent Condensation In Tents

Have you ever spotted dampness in a tent and wondered, is my tent leaking or is it condensation? Managing moisture in tents requires some ‘know-how’ so we’ll cover ways to identify the difference between leaks and condensation in tents, why it’s happening, and way to mitigate their effects.

Is your tent leaking?

Let’s start with a leaking tentthese are usually relatively simple to determine. There will be a visible point of leakage, usually forming a stream as water passes through the fly fabric.  The culprit can usually be located by following the stream to where there is a tear or hole in the tent fabric. Or potentially at a seam between two pieces of fabric that aren’t sealed properly.

Conversely, if you witness a film of water across the fly fabric, this is consistent with condensation.

All tent fly fabrics will have a HH rating. This rating refers to the water pressure the fabric can withstand before a single drop passes through the fabric. Through usage, and exposure to UV, this rating decreases over time as the fabric and coatings degrade. But in general, if a tent is pitched correctly to allow for efficient run off of water, a 1000mm HH will be roughly enough to be classed as waterproof. At Zempire we make all our tents well in excess of that, up to 8,000mm HH.

What is condensation and humidity?

Moving on to condensation, this is something we’re taught in physics class back in school. It is the process in which a substance changes from a gas (or vapour) to liquid, and this happens when the temperature of the gas (or vapour) decreases. 

Relative to condensation is humidity, which refers to how much liquid is in the air. When air is warm, water molecules fly around in the air as a gas, unable to come together and form a liquid. As they cool, they slow down, combine and release the liquid from the air by forming droplets. It’s worth noting that warm or hot air can hold twice as much liquid as cold air! 

Why does condensation form in tents?

When we’re out camping, we create protective shelters (tents) to shield us from the elements – keeping the wind, rain and sun out. This also has the counter effect of trapping a lot of the air and humidity in. This internal humidity can be increased from a wide range of sources including the ground, plants, wet clothing, food, drink, people and pets.

During the day this tends to cause few condensation issues, since we often open our tent up to ventilate, allowing the humid air to circulate into the atmosphere. But, when night-time comes, the sun goes down, and we close up our tent.

By doing this, we trap the residual warm humid air inside the tents. Then, adding to the moisture-creating factors listed earlier, we humans release approximately 2 litres of liquid per day through breathing alone. So, during an 8-hour sleep that is approximately 700ml of liquid per person! Constantly adding to that warm humid air.

The lowering temperature then cools the parts of the tent it comes into contact with. And when the warm humid air makes contact with a cool surface the moisture in the air releases and forms water droplets. This will generally be visible as a film of water droplets on the inside of the fly fabric.

However, there are some situations where condensation may turn into drips. This can lead to a misdiagnosis as a leak. For example:

  • Very humid air creating a large volume of water droplets becoming to heavy to stick to the fly fabric.
  • Sub-optimal tent pitching that creates a fold or imperfection in the fly fabric shape that cause the condensation to channel to a specific point. Again, this is often perceived to be a leak.
  • Object(s) touching the inside of the fly sheet. Much like the sub-optimal pitching example this creates a point for the condensation to channel to.

Preventing condensation in a tent.

As condensation is a natural process it can rarely, if ever, be avoided. However, to mitigate it you can do the following:

  • Ventilate – keep all vents, windows, doors open to allow air flow. This allows the warm humid air to circulate out into the atmosphere. Obviously, this also allows cooler night air into the tent so you will need to find a balance you are comfortable with.
  • Pitch your tent on flat ground - so that you can be sure to make the fly sheet taught with no folds or imperfections to its shape.
  • Utilise sleeping pods – sleeping pods help absorb some of the humidity in the air. In contrast you will often find single skin tents without sleeping pods are prone to much more condensation on the inside of the fly sheet than those with sleeping pods.
  • Additional Ground Sheet cover – to decrease ability of ground moisture to be released into the air inside the tent.

In summary, condensation is a perfectly natural process, and nothing to be alarmed by. By taking precautions and understanding its principles you can help manage its effects to have a more comfortable camping experience. Happy camping!