Thats an interesting question. Mountain Hardwears EV3 ($750; mountainhardwear.com) is a serious, three-person expedition tent that uses single-wall design. For its weather shield, the EV3 employs a version of Conduit, a proprietary Mountain Hardwear laminate that the company has long used in clothing and even sleeping bags. Conduit is waterproof, yet has decent breathability. By going with a single wall, the EV3 manages to be exceedingly sturdy yet still weigh right around seven pounds, depending on how many accessory cords and stakes you pack. Thats pretty good! Typically a tent of that size and for that purpose would tip the scales more in the range of ten or 11 pounds.
I havent used the EV3, so I cant address the ventilation question directly. But Im willing to believe that under certain conditions you might see more condensation in the EV3 than in a double-wall tent. Thats just the nature of the beast. If you have three people breathing away inside on a still, cold night, theres no fabric on earth thats going to fully prevent condensation. That can be mitigated by trying to pitch a tent such as the EV3 so its vents catch some breeze, and by opening vents high and low so that warm air can escape out high and cool air can be drawn in from below.
Its also likely that the EV3 wont be as warm as a double-wall tentagain on cold, still evenings. Thats because double-wall tents have an air layer between the canopy and fly that can act like the space inside a double-pane window. That also works to your advantage if youre lounging around the tent on a warm, sunny daya double-wall will be a little bit cooler.
You have to weigh that against the really impressive weight savings of the EV3, as well as its extremely rugged construction. Myself, I wouldnt hesitate to take it on big, serious mountains.
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