Outdoor Research Lab - Montana State University

Montana State Universities Outdoor Research Laboratory

"First I'd like to congratulate you on a fabulous design. The 2R's ability to resist condensation under demanding conditions was spectacular."

Senior Research Engineer at Montana State University, Dr. Ryan N. Jordan, with the Outdoor Research Laboratory conducted a study comparing The North Face Mountain Tent with Warmlite's 2R. The tents were to be evaluated on heat retention within the tents as well as amount of condensation retained inside the tents. The tents were tested on two consecutive nights in nearly identical conditions.  Before the experiment began Dr. Jordan was impressed with Warmlite's superior ventilation system (the chimney system) in both single and double wall tents, this combined with its easy set-up and high-wind durability, impressed researchers. Dr. Jordan also commented that Warmlite was the only company to produce tents that successfully integrated non-breathable double-wall structure and the chimney ventilation system.  Both tents were pitched with foot ends towards the incoming prevailing wind, all vents in the Warmlite 2R were fully opened. The fly of The North Face Mountain Tent was pitched taut with special care taken at the foot and head sections to allow convective air exchange between the double wall and the atmosphere.  For each test a 5'7" 140 lb adult male entered the tent, closed all windows and doors, crawled into a down sleeping bag and began monitoring the temperature and relative humidity at several locations within the tent.  The Results  Outside ambient temperatures = 21 +/- 1*F (nighttime) and relative humidity = 74% +/- 2%, resulting in dew point temperatures of approximately 17*F.  The North Face Mountain Tent

 
• In-Tent Temperature/Humidity/Dew Point: 27*F / 96% / 26*F
 
• Inner Wall Temperature/Humidity/Dew Point: 23*F / 99% / 23*F
 
• Insulating Wall Temperature/Humidity/Dew Point: 23*F / 97% / 23*F
 
• Weight of Moisture Retained By Tent During Test: 11 oz
 
• Condensation Observations: Condensation noticeable to touch on upper 2/3 of inner wall around circumference of tent; condensation droplets visible on entire upper 1/3 of inner wall; condensation droplets visible on 95% of the inner surface of the outer wall.

Warmlite 2R

 
• In-Tent Temperature/Humidity/Dew Point: 34*F / 88% / 32*F
 
• Inner Wall Temperature/Humidity/Dew Point: 32*F / 85% / 30*F
 
• Insulating Wall Temperature/Humidity/Dew Point: 28*F / 74% / 24*F
 
• Weight of Moisture Retained By Tent During Test: 1 oz
 
• Condensation Observations: Condensation noticeable to touch on single end liner at head of tent; condensation was not noticeable to touch or visible on any portion of the single wall end liner at foot end, inner surfaces of the double walls, inner surface of the outer wall, or outer surface of the inner wall. Seemingly little visible condensation on the inner surface of the inner wall of the tent when compared to the outer wall.

Conclusion  The Warmlite 2R maintained an in-tent temperature 7 degrees warmer than The North Face Mountain Tent, and 13 degrees warmer than the outside ambient temperature. The non-permeable walls in the Warmlite tent prevents heat from transferring to the outside, and the chimney venting system removes the humidity while still retaining warmth. The Warmlite 2R also had significantly lower in-tent humidity, 11% lower, this also contributed to the 10 oz lower weight due to condensation. While this may not matter if the tent has the ability to air out during a following warm day, but if the weather does not allow for this or if the trip has the user packing up camp in the morning, the user then has to carry that condensation.