advantages of double membrane system vs Cable net system

INSULATION

DUOL double membrane system provides excellent thermal insulation of 1.74W/m2K, measured at Finnish Research Institute VTT. This is achieved by inflating the interspaces between two membranes with air (approx. 50-100 Pa, compared to the air dome inside pressure). This slight overpressure ensures that the membranes are always inflated, while the static air is an excellent insulator. Compared to cable net system, which total thickness is only a couple of centimeters narrow, and prevails a very poor insulation.

CONDENSATION

Thanks to excellent insulation, achieved by DUOL double membrane system, there is no condensation phenomenon inside the air dome. In cable net system, because of poor insulation and big thermal bridges, there is always problem with condensation on the outer side of the dome.

FIRE RESISTANCE

All membranes are fire retardant, certificated by following certificates: M2/NFP 92-507, TEST 2/NFPA 701, CSFM T19, B1/DIN 4102-1, BS 7837, B1/0N0RM B 3800-1, M2/UNE 23.727, VKF 5.3/SN 198898. Compared to cable net system, the layers are not fire safe, in fact they are extreme flammable, which presents a great risk to the whole of the structure.

DURABILITY / LIFE EXPECTANCY

In DUOL double membrane system, the replacement of the membrane is not required and the life expectancy is extended to 40+ years, based on tests, experiences and existing projects. Compared to cable net system, where the layers have to be replaced every couple of years, due to friction between cables and fabric.

LOSE OF TRANSLUCANY

Duol fabric has self-cleaning characteristics and is absolutely maintenance free. Cable net system is great obstacle for self-cleaning mechanism. Cables on the outer side of the membrane prevent the dirt, organics microorganism… from sliding of the surface. Dirt cannot be totally removed, therefore translucency is reduced what represents great costs for the client.

RIGIDITY

Thanks to DUOL expanded double membrane system, the DUOL domes are very rigid and vandalism resistant. In case of any damage on the outer membrane, the inner membrane still hold the proper air tightness and consequently pressure – air dome stability. Compared to cable net system, where in case of any membrane damage there are big air losses and the structure stability is jeopardized.

SNOW

Duol air dome has totally flat surface and lacquering finishes, which ensure that the snow slides form the air dome. Compared to cable net system, where cables on the outer side of the membrane prevent the snow from sliding of the surface, which lead to the snow collection and the whole structure is in a big danger to collapse.

SEASONAL INSTALLATION / DISMANTLING

As two membranes are welded together, the installation process is extreme fast. Membrane should only to be spread, connected and anchored and the erection of the dome can be made. This operation can take only a few hours. The same is in seasonal dismantling. As the cable net system requires spreading of different layers, connecting them and afterwards installation of metal net, the installation/dismantling process in significantly longer and costs are higher.

INTERNAL PRESSURE

The pressure kept in the DUOL domes is minimal, from 150-250 Pa in normal situations, what ensures perfect stability in all weather conditions and less energy consumption. Compared to cable net system, which due to its weight requires much bigger internal pressure (250-400Pa) which leads to much bigger electric energy consumption.