Tent condensation happens to everyone. It’s one of the unavoidable consequences of camping or backpacking with a tent, but it’s usually just a nuisance and not the end of the world.
Still, there are a lot of misconceptions about tent condensation and whether you can buy a tent that completely prevents condensation. Unfortunately, the laws of physics are hard to avoid. Condensation is a natural process that occurs with all tents, both single-wall and double-wall tents, no matter what fabric or materials they’re made of.
What causes tent condensation?
Condensation forms when humid air encounters a colder surface like the interior walls or roof of your tent. It’s the same process that occurs when you take a hot shower and the steam makes your bathroom mirror wet. Steam, which is simply water vapor in a gaseous form, is cooled when it hits the mirror, converting it to liquid water droplets that cover the mirror with moisture.
How to reduce tent condensation
The amount of condensation you experience is a tent is a function the humidity in the air around you and the moist air you expel from your lungs when you exhale. In order to reduce the amount of condensation that forms in your tent at night, you should:
- Ventilate your tent by rolling back the rain fly or leaving the vestibule door open so humid air and moist exhalations from your breath can escape.
- Remove wet clothes or shoes from your tent at night. Dry them outside or put them inside a stuff sack to reduce nighttime humidity.
- Cook and boil water outside your tent to avoid increasing the interior humidity level.
- Avoid camping near streams, lakes, ponds, or in wet or marshy areas where the humidity is higher. Yes, it’s nice to camp next to a water source, but you’re asking for tent condensation when you do it.
- Avoid setting up your tent at a low point in the landscape where cold air pools at night. If your tent’s walls and fly are warmer, you’ll have less condensation.
What is the best tent for avoiding condensation?
There really is no best tent for all climates, seasons, and locations. Good campsite selection is always going to be the most important factor in preventing tent condensation. But different styles of tents have different pros and cons that are worth considering.
Single-wall Tents: Ultralight-style tents, tarp tents, and tarps are usually quite easy to ventilate, although they can also be quite drafty in cooler weather. You might even have to bulk up on your sleep insulation to stay warm at night. However, if you only camp in warmer weather, they can be a good choice.
Double-wall Tents: Double-wall tents tend to have less air-flow, but can be used across a wider range of temperatures because they retain more body heat at night. While they don’t eliminate internal condensation, they keep it away from you and your gear. Any water vapor inside your tent, from your breath, for instance, will pass through the mesh inner tent and collect on the inside of the rain fly instead.
What if it’s raining?
If it’s raining, your chance of experiencing tent condensation will increase because there’s more humidity in the air. It’s a lot like camping next to a stream or a pond, but many times worse. If you have a single-wall tent or shelter, your best bet is to carry a small camp towel or bandana that you can use to wipe away any tent condensation before it drips onto your gear. If you’re in a double-wall tent, make sure that the rain fly is stretched as far away from the inner tent as possible, particularly along the sides and corners of the tent. If your fly clips onto the base of your inner tent, consider staking it out separately to promote more airflow between the layers.
How significant is moisture in your breath?
When you sleep at night, you exhale about 1 liter of moisture. You’re not aware of it, but its one of the reasons why you wake up thirsty at night or in the morning. If there are 2 people in the tent, then you have to deal with 2 liters of tent condensation, and so on, as you add more people. If you’ve ever camped in a tent in winter, the inside of the rain fly will usually be covered in frost in the morning, mainly from occupants’ breath.
What if your sleeping bag gets wet from tent condensation?
Most sleeping bags and quilts have a water-resistant exterior shell fabric or one that has a DWR coating to repel water. If however, the shell gets wet or damp, your best bet is to dry it in the sun the next morning while you’re having breakfast or during a rest break during the day. Stopping to dry wet gear, tent flies, and clothing is a normal everyday activity when backpacking and it’s good to get in a habit of doing it when necessary.
What if your tent or tent fly is soaking wet in the morning?
If you’re not in a rush, you can let it dry in the morning sun, but that might take a while. If you have to get going, another option is to wipe down the rain fly using a clean camping towel, which will remove a significant amount of that water. After that pack the fly away in an outer pack pocket or in a separate plastic bag and dry it later in the day during a rest break.
Can you set up a wet tent fly at night?
Absolutely, although you might want to pitch camp a little early that evening so that your tent has a chance to dry out before you want to get into it. I’ve set up damp tents in summer and had them dry within an hour, but your mileage may vary.