Ventilated backpacks have suspended mesh back panels to help dry perspiration when you’re carrying a backpack. The mesh is suspended above a concave cavity so there’s a big air space behind your back to help evaporate moisture. Deuter Packs, which is still the largest backpack manufacturer in the world, is credited with inventing ventilated backpacks, or trampoline frames, as they’re sometimes called. Since then, Osprey has emerged as the biggest producer of ventilated backpacks, as well as REI and Gregory.
But how effective are ventilated backpacks at preventing sweat or drying your shirt more quickly? Besides anecdotal evidence that people “feel cooler,” is there any evidence that people burn fewer calories when they carry a ventilated backpack, or that they need to hydrate less, or some other measurable benefit?
It’s not an outrageous question to ask because there are pros as well as cons to carrying a ventilated backpack. For example, some ventilated packs pull you backward and off-balance because they have such large air cavities behind the mesh. This can actually make you burn more calories, to compensate against the forces pulling you backwards. The same concave intrusions make it more difficult to pack ventilated backpacks efficiently, carry hard-sided bear canisters with them, or find gear buried deep in your pack.
Deuter, to their credit, commissioned a study with the Hohenstein Institute, a test laboratory, and research institute, to quantify the benefit that ventilated backpacks. They found that the three-way mesh ventilation system in Deuter’s packs “reduces perspiration by 25%.”
That doesn’t sound like much, but it could add up to a considerable weight savings in the amount of water you needed to carry in an arid environment where you have to carry a large amount of extra water. For example, if you needed to carry 8 liters of water with a non-ventilated pack, you would only need to carry 6 liters with a ventilated one. That’s a weight saving of 4.4 lbs, which is not insignificant.
But how often do you have to do a long water carry where you hike? I rarely carry more than 2 liters and often carry less.
How do you rationalize ventilated backpacks?