The single-wall tent as a starting point
Most tents are designed with a double-wall, meaning two layers of fabric that separate the tent's interior from its outdoor environment. Samaya was born from the conviction that advancing single-wall tent technology was the key to revolutionizing bivouac equipment for many uses. Offering single-wall tents optimized for waterproofness, breathability, and air permeability has become an obsession for the Samaya R&D team.
With the right materials, this single-wall design offers the advantage of a significant reduction in weight and folded volume, as a single-wall tent by definition requires less fabric than a double-wall tent. Furthermore, the single-wall tent provides better resistance to wind and inclement weather due to the greater integration of the various tent elements and the balloon effect observed in windy conditions caused by increased pressure on certain parts of the tent. Depending on the conditions, the ease of setup and takedown can prove invaluable.
Water resistance
Waterproof requirements for a jacket are not the same as for a tent.
Unlike a jacket, there is no friction or pressure applied directly to the walls of a tent fly. The equivalent water column generated by very heavy rain without friction is 2,000 to 3,000 mm[1]. Therefore, a waterproof rating of 10,000 mm is more than sufficient for the walls. On the other hand, a high level of waterproofing is essential for the floor, due to the pressure exerted by the individual's weight. This is why the majority of our 4-season tent floors have a waterproof rating of 20,000 mm.
[1] The millimeter water column, also known as Schmerber, is a unit of measurement for the water resistance of textiles. The value associated with mm of water column is obtained by performing a waterproof test according to the ISO811 standard. This test consists of continuously increasing the pressure exerted by water (in other words, increasing the intensity of the rain) on a textile. When the water passes through the textile, the pressure value is noted, and the associated millimeters of water column are calculated. This value therefore corresponds to the waterproof limit of a fabric.
Air permeability
We distinguish two phenomena:
Air renewal through pressure: this corresponds to the airflow that passes through the fabric under a certain pressure. For example, if there is wind, a slight, imperceptible flow of air enters the tent. This outside air, which is normally composed of oxygen, replaces the air inside the tent, which has been depleted of oxygen due to the user's breathing.
Air renewal through diffusion: the phenomenon of diffusion is a natural process corresponding to the spreading, equalization, and homogenization of particles and materials. This occurs either during a change in temperature or material concentration, or when two different levels of temperature or material concentration meet. The phenomenon of diffusion can occur when no obstacle hinders the transport of particles from one medium to another. As the user breathes inside the tent, they inevitably reduce the O2 concentration level and increase the CO2 level. Only a tent with air-permeable walls allows for air renewal through diffusion, continuously balancing the O2 concentration inside the tent.
Breathability
Breathability refers to a fabric's ability to wick away water vapor. This is notably generated by breathing, as we produce 800 mL of water in 24 hours. Furthermore, as the temperature drops, the relative humidity of the air increases: therefore, fewer H2O molecules are stored in the same volume of air (Mollier diagram)[1].
When the relative humidity of the air reaches 100%, the air is completely saturated. Water vapor from breath condenses and forms droplets. The breathability of a fabric thus helps to wick away water vapor and therefore limit condensation. The rise in temperature inside the tent due to human presence and the retention of this heat also makes it possible to keep more moisture in gaseous form, thereby facilitating its evacuation to the outside.
[1] If we compare the size of an air/water molecule on the order of a nanometer to liquid water on the order of a millimeter, liquid water is 100,000 times larger than the air/water molecule.
The Samaya technology developed for the tent
Nanovent®
Designed to provide waterproofing, breathability, and air permeability to the tent, the Nanovent® membrane is made of a random interlacing of polyurethane filaments with nanometric dimensions (1 billion times smaller than 1 meter). By managing the density of the interlacing achieved through electrospinning, the membrane pores are sized to be too small to let water droplets pass through, but wide enough to allow air to pass. Nanovent® technology thus ensures unprecedented waterproofing.
This electrospun membrane is combined with two layers of nylon. The inner layer is a hydrophilic nylon that, when condensation occurs, allows the water to spread over a large surface area and therefore dry more quickly. The outer layer is a hydrophobic nylon (water-repellent treatment) that promotes the smooth flow of water across its surface. These layers ensure the mechanical strength of the fabric and protection for the electrospun membrane. This 3-layer laminate is used on the tent walls in the ALPINE and 8K ranges.
The role of the membrane and the three major families of membranes
Membrane fabrics make it possible to combine these three essential characteristics for the efficiency of a single-wall tent. A membrane is a thin structure, relative to its size, that separates two environments by preventing some or all matter from passing from one to the other, depending on its pore size and thickness. The membrane acts as a filter to ensure the water-tightness, air permeability, and breathability of the single-wall tent.
There are three main families of membranes with specific properties:
To make optimal use of the single-wall construction, Samaya relies on its Nanovent® technology, specifically developed for the tent to address the challenges of waterproofing, air permeability, and breathability.
