Ventilation

A Fine Art

Building functional tent ventilation systems is an art –but one grounded firmly in science. The problem: your tent needs to keep out the weather yet let in enough air to battle condensation and keep you comfortable. A poorly placed mesh panel can create a rain or snow storm in your tent, and an outer tent that does not go all the way to the ground can let wetness and snow in. At the same time, there must be a way to move moisture out of the tent, to limit condensation.

No tent is completely immune to condensation: in some conditions, it is simply unavoidable. Cold temperatures with high humidity is especially likely to create condensation in a tent, as is rainy weather, or the moisture-laden air of coastal areas. Even tarps will collect condensation in these sorts of conditions. Wet gear (and humans or dogs) in the tent or vestibule will also contribute to condensation problems. And if the humidity outside the tent is higher than within, it is simply not possible to vent that moisture laden air – unless you have a heater and a fan!

All Hilleberg venting systems are built to function no matter the weather. In all our tents, at least one main vent is placed high up, to harness the chimney effect, which moves warm, moist air upward – and, thanks to the vent’s placement – out of the tent. The main vents also have cor­re­spond­ing, adjustable components in both the inner and outer tents, so you can have less or more venting, as you choose (and as the weather dictates). Hence the vent covers on our dome tents, which cover highly effective roof vents, and the uniquely placed “tunnel” vents on our tunnel tents.

To supplement the main venting, inner tent doors have no-see-um mesh panels covered with equal sized, zipper-adjustable fabric panels, which allow for both venting and weather protection options. In addition, our double wall design is integral to our effective venting, and to fighting condensation. In single wall tents – or in any tent’s vestibule – rain hitting the outside of the tent can knock condensed moisture off the walls inside, which can make it seem as though the tent (or vestibule) is leaking. Our outer tents keep the weather out. Our inner tents, whose fabric is both very breathable and highly water repellent, lets moisture vapor escape into the space between outer and inner tents. There it cools, and turns to droplets, and the inner tent fabric’s water repellency prevents the liquid moisture from penetrating back into the tent.

The Facts About Condensation

Condensation is the exact opposite of evaporation. Air inside an occupied tent is warm and humid – which means it has lots of “evaporated” water molecules zipping around in it. That warmer, moister air rises and hits the tent wall (which is cooler because of conductive cooling), and those water vapor molecules slow down and “stick” to the cooler surface: they “condense” out of the air and onto the tent wall. The same thing can happen between your sleeping pad and the floor of the tent. Hilleberg tents combat this process with:
Vents situated high up to let warm, moist air out.
Double wall design with water repellent, breathable inner tent fabric to let vapor pass through, and to keep actual water out.
More venting via mesh panels in the inner tent doors.

Hilleberg venting solution

All weather venting system

Air can move freely in a Hilleberg tent, even if it is dug down deep in the snow, or covered by high grass, since the main vents are placed high up. In addition, mesh in the doors, backed with adjustable fabric panels, allows air to move into and out of the inner tent.

Breathable, water repellent inner tents

Our inner tent fabrics are highly breathable yet remarkably water repellent: moisture vapor passes through them quite easily, yet they can actually carry water, bucket-like. In addition, they have impressive air permeability, so that air can circulate better throughout the tent, thus helping fight condensation and increase overall comfort.

Model-optimized vents

Vents in Hilleberg tents come in all shapes and sizes, each engineered for that particular model’s design.

The vent integrated into the Nallo’s door.				The Saivo’s large roof vent.				A vent on the Keron, showing its snow-proof panel rolled and stowed.
The Nallo and Nallo GT’s interior, back wall vent rolled up for maximum venting.				The Nallo and Nallo GT’s rear outer wall guyed out for maximum venting.				One of the two zipper vent and venting fabric foot panels on the Akto.