The use of NSHEVs for walls requires that natural smoke and heat exhaust ventilation system, NSHEVS, always has enough NSHEVs available on a wall of the building not exposed to winds. It also requires that NSHEVS is supplemented by a wind speed and direction control system, thus avoiding the opening of devices exposed to headwinds.
Compliance with these circumstances, which are necessary to ensure correct NSHEVS operating with any weather condition, leads to double the number of NSHEVs required and to insert a control and command circuit into the system, with a significant increase in costs. The use of roof NSHEVs on saw-tooth roofs can protect the device from side wind but does not give full guarantee that in each configuration there is no headwind which contrasts smoke exit.
Upon these considerations CAODURO^® has developed its SMOKE SHED™, designed and patented with suitable retractable aerodynamic spoilers, which are activated only when the device opens in case of fire.
These guarantee the Aa value (aerodynamic free area) evaluated in presence of wind. The opening angle is optimized in order to obtain this Aa value and does not have any protrusion, which normally the market offers with an unsightly effect.