How to deal with tent condensation
Posted by Nathan on 26th Dec 2019
Best ways to deal with tent condensation.
Preventing & Managing Tent Condensation
Tent condensation can be prevented through site selection, ventilation, and tuning shelter size. If condensation does occur, it can be managed through liners, tent stoves, or mechanical drying.
How to Prevent Tent Condensation
- Site Selection
- Choose dry ground, high ground, and away from water. A breeze or under trees will keep condensation away.
- Open a door or lift the skirt of your tent to let air through.
- Shelter Size
- Small tents with a lot of people in them condensate more than big tents with fewer people.
How to Deal with Tent Condensation
- Liners catch drips and divert them to the ground. Turns a singlewall tent into a doublewall tent.
- Tent Stoves
- Wood heat dries the inside of the tent, as well as your gear.
- A quick rub down with a cloth removes condensation from tent walls.
Tent Condensation is as common as the morning dew. For campers, it is a frequent and annoying companion. ALL tents will condensate under the right conditions.
The goal of an educated camper is to minimize the negatives of tent condensation through site selection and ventilation, and to effectively deal with it when it is unavoidable so you have a dry ride and an enjoyable trip.
What causes tent condensation?
Warm air holds more moisture than cold air. When air cools water vapor is squeezed out and must find a place to go.
Condensation can collect on the inside of a tent canopy for several reasons.
- Temperatures drop at night, meaning night air can’t contain as much water vapor.
- People exhale water vapor with each breath.
- 98.6° humans in a tent act as a heat source, meaning the temperature inside the tent is probably warmer than outside the tent.
To summarize, you have a heat source and a water source in the tent, with colder air outside. The two meet at the canopy. Heat goes to cold, so as the warm humid air inside contacts the canopy it cools, water vapor condenses from gas to liquid, and your tent canopy gets wet.
Why is Tent Condensation Bad?
You may be wondering why tent condensation is so often talked about. The problems caused by condensation run from mild annoyance to fun-killing misery.
Of least concern is a thin film on the tent canopy. That film becomes annoying when you brush your head against the tent in the morning, and is concerning when the foot of your sleeping bag becomes wet through contact with the tent.
Worst of all is a heavy layer of condensation soaking the inside of the canopy, with a heavy rain or thunderstorm outside.
Heavy drops of rain and buffeting wind “ping” the canopy and cause the condensation to break free and mist over the interior. This can turn a fun trip into a character building exercise in a hurry. Luckily these bad experiences can be avoided with a bit of education.
Warm humid air inside + Cold air outside = Condensation
To prevent tent condensation we have to work on the two factors of the condensation equation...either the warm humid air inside the tent, or the cold air outside.
The easy ways to target this is through site selection, ventilation, and tuning your shelter size. If condensation does happen (and it will at times) then you can deal with it by using liners, a tent stove, or by drying your canopy.
Site Selection and Tent Condensation
Keys for site selection:
- Dry ground
- High ground
- Avoid water
- Find a breeze
- Camp under trees
The first key in site selection is to look for dry ground. Setting up on soaked ground is sometimes unavoidable, but if you have an option, find a dry site.
Cold air sinks through the night. Creek beds, valley bottoms, and low spots collect cold air, increasing your condensation potential. Picking higher ground to pitch your tent will give you a drier ride.
Camping next to a lake may be beautiful, but the air around water is more humid than at a slightly higher elevation. Pitching camp on a bench above the lake will decrease your condensation risk.
A light breeze can drastically reduce condensation potential, and breezy areas are commonly found on ridges, benches, or higher elevations.
Tree canopies create a microclime of warmer air. This warmer air outside the tent means less chance of condensation inside the tent. (Please always remember to look up when camping under trees, and avoid dead trees, hanging limbs, or anything that looks like it could fall if a strong wind kicks up. Camp safe!)
Don’t Condensate, Ventilate!
Ventilation is perhaps the most important tool campers have to prevent tent condensation. You don’t always have your choice of sites, but you usually can control your ventilation.
Ventilation is key because it works on both sides of the condensation equation - humidity AND temperature differential.
Airflow through the tent moves water vapor outside. Airflow also allows the warm air inside the tent to escape and be replaced by the colder air outside. If internal and external temps are the same then condensation won’t collect on the canopy, or if it does it won’t be as severe.
The effectiveness of ventilation is determined by the amount of ventilation. More air changes per hour allow water vapor to escape quicker. Tent size plays a part here, as lifting the perimeter of an 8 Person Teepee by 4” won’t have as big an effect as lifting a Cimarron Pyramid Tent skirt by 4” due to the larger volume of air trapped inside the bigger tent.
Likewise, lifting one side of the skirt won’t produce as many air changes per hour as lifting the entire skirt.
Match your venting to your conditions.
How to Ventilate a Seek Outside Tent
The two main ways to ventilate one of our teepee tents is to use the doors or to lift the skirt.
Door zippers open from the top down or the bottom up, giving you two ways to ventilate.
- Partially unzip from top down and prop the zipper open with a stick.
- Partially unzip from the bottom up and tie the flap back to let in air.
The advantage of door venting is ease of use, and how quick it is to change. If things get drafty or a shower starts up, simply zip the door shut and you’re buttoned up.
Lifting the Skirt
Lifting the skirt of the tent can be done over part, half, or the entire tent. This is usually accomplished by extending the stake points and raising the pole.
Our standard tents have very robust stake loops that require add-ons in order to lift the skirt, while the Light and Ultralight versions of tents such as the Cimarron or Redcliff come with an integrated Lineloc stakeline system that makes it very easy to ventilate. Our zipperless trekking pole tents such as the Eolus and Silex also feature the lineloc staking system.
Standard Tent Venting
There are three easy ways to lift the skirt on standard tents, with two being products that we sell.
- Lineloc Extension Kit - this kit consists of linelocs that attach to your stake loops, and cordage that runs to the stake. The lineloc makes tension a breeze to adjust.
- Shelter Gatekeeper Straps - these handy straps do the same thing as the lineloc kit, but are a bit heavier and a bit easier to use. They consist of a ¾” web strap with a stake loop in the middle and a gatekeeper buckle on each end. Stake the middle and you’ve got one free end to attach to the canopy stake loop, and you can attach the other end to a nest if you are using one.
- Taut Line Hitch Stakeloop Extension - that’s a mouthful, but is super simple to tie. Start with 2.5 to 3 feet of cordage and tie a loop in one end. Run the other end through a stake loop and then connect it back to itself with a tautline hitch. The loop end gets staked, while the tautline hitch allows length and tension adjustment on the fly.
Tuning Shelter Size
Given similar amounts of water vapor trapped inside, a big tent will condensate less than a small tent. This is because the condensation spreads out over more square footage of canopy and is thinner, causing fewer problems.
This matters in camping applications because if you squeeze maximum occupancy out of a small tent your condensation risk skyrockets. Lots of people equals lots of water vapor from breath, and that vapor doesn’t have as much canopy to spread out over.
If you’re on an ultralight backpacking trip, you take the weight savings of a smaller tent and then manage condensation risk with airflow or other means.
If you’re not as focused on lightweight backpacking and would rather have a more comfortable camp, then upsizing your tent can lessen your condensation potential.
Tents are often broken down into singlewall or doublewall, the difference being obvious - singlewall has only the outer shell of the canopy, while doublewall has the outer canopy and an inner lining.
A common misconception is that singlewall tents condensate more than doublewall tents. In truth both condensate, but the inner lining of a doublewall tent keeps condensation away from occupants, and because it’s out of sight out of mind, they don’t notice it.
Liners turn a singlewall tent into a doublewall tent. They partially cover the interior canopy of the tipi so that if condensation occurs and is heavy enough to drip the liner will catch it and funnel it to the ground on the outer perimeter, keeping occupants dry.
Liners are particularly useful in cold weather when airflow and hefty amounts of venting aren’t wanted due to the drafty cold conditions.
Liners are removable and can be used when desired, or taken out when not needed.
Tent wood stoves provide a dry heat that changes the dynamics of the condensation equation. Warming the air inside allows it to hold more water, which allows liquid condensation to vaporize. Once vaporized, opening a door to let the warm humid air escape dries out the interior. Even relatively soggy ground can be dried over time using this method.
Portable wood stoves help dry out wet gear as well, removing another source of water vapor. In cold weather the inside canopy is often frosted in the morning from water vapor expelled through breathing. Firing up the stove will quickly melt and vaporize this frost so that it can be moved out of the tent.
Carrying a bandana, a buff, or a microfiber towel is a simple but highly effective way of removing tent condensation.
A quick wipe down with a rag of your choice removes heavy condensation, quickly drying the inside.
Check out our videos on condensation for more information.…