Condensation
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MoonLight tents have the design, materials, and features to minimize condensation and, if conditions make it inevitable, they handle it well.
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Air can only hold so much moisture and the colder the air is, the less it holds.
Such a dry statement for such a cold, wet, and miserable phenomenon.
With luck, most of your trips will be condensation free.
But nights are a cool-off period, rainflies get cold and humans breathe and perspire. We're all generators of warm moist air that cools as it floats up, expands and mixes with the rest of the air inside our tent. The hope is that the moisture will be able to stay in the air. But, in conditions with humidity too high and/or temperatures too low, condensation will occur (it can get pretty darned bad too, something I call pseudo-leaking). And when a lot of condensation happens, it will be one of the biggest tests of your tent, the brand of the tent, its materials, and frankly, its designer, because this is usually what it looks like on the outside as it happens:
And on the inside, every one of those horizontal wrinkles is doing it's very best to gather enough condensation to drip on you. Oh wait, isn't that part of the polyester versus nylon discussion?
What's a tent designer to do? Well, the basics are:
1) MoonLight tents have GREAT separation between the rainfly and the tent. This prevents the rainfly from ever touching the inner tent walls which would create a cold spot to cause condensation AND give it a way to come into your tent. The door walls have vestibules, so the rainfly is a long way away. The sides have good separation that can be adjusted with pullouts. And thanks to our no-sag polyester fabrics, the rainfly stays off the roof net even in "wrath of god" rain conditions.
2) To PREVENT, use a VENT: MoonLights always have two vents right near the top of the ridgeline and the '+' models also have vents in the vestibules. This is the best way to get rid of the warm moist air from occupants before it can condense inside. It also offers a possible way for a breeze to bring in drier air, assuming the outside isn't so wet and cold that there's fog or a strong dew (best stay closed up in those conditions, at least for awhile).
3) The lower edge of the MoonLights' rainfly is lower to the ground than many tents. This covers the inner tent lower sidewalls so they stay warmer and it reduces the height of rain-splash on the walls.
4) Here's a not-basic MoonLight design feature that manages the flow of condensation on the underside of the rainfly so it doesn't drip. Imagine condensation as a thin layer of water flowing downward on the underside of the rainfly. Places where the flow is blocked is where it will build up and drip. That means a tent rainfly should have an unambiguous high point (MoonLights, yes) and smooth downward sloping panels with no cross-seams or seam tape (also yes). The collection point at the bottom of those panels is where condensation will drip and the MoonLights are designed so the drips go onto the ground or a part of the ripstop inner tent steep enough that it doesn't matter if it gets a little wet. This is a big reason the MoonLight's rainfly roof is so wide, to get drip points out past the edge of the net.