Condensation is the build-up of moisture inside your tent due to differences between the inside and outside temperatures. There are three main sources:
- Weather Conditions: High humidity, low temperatures, and rainy conditions create the most condensation.
- People: We produce about 1 - 2 pints of moisture per night through breathing and skin evaporation.
- Wet Environment: Wet ground or wet gear stored inside the tent.
While no tent design can eliminate condensation, the key to reducing it is ventilation. Cooler, drier air has to flow into your tent and warm, moist air must escape. We have designed a variety of ways to do this.
To start, the tent body and ceiling are made of breathable and mesh fabrics. This allows moisture to escape the interior of your tent. However, it must also be able to escape the waterproof fly, and every MSR rainfly has a peak vent that provides protection from the outside, while still allowing essential, free-flowing fresh air to move through your tent. You can also leave a door open in good weather, or take advantage of the double sliders on the doors to vent from the top where warm and moist air tends to accumulate.
Make sure to leave at least two vents open if possible, allowing any breeze to provide cross-flow ventilation for maximum circulation. Guying out your rainfly will also increase ventilation in hot or humid conditions - pulling the fly away from the tent body.
On many tents, there are small ventilation flaps that have a very small "kick-stand" sewn into the fabric. If you haven't noticed these before, look to see if they are on your model of tent, and be sure to stand them up with the small piece of Velcro on it. This will help open those ventilation points.