A natural smoke and heat exhaust ventilation device (NSHEV), e.g. in the form of a skylight or a skylight dome - each including an opening system - discharges smoke and hot gases to the outside through natural buoyancy in the event of a fire. A NSHEV is usually part of an NRA and can be both a skylight and an opening in the exterior wall. The properties for a NSHEV are specified in DIN EN 12101-2, and rules for installation are laid down in DIN 18232-2.
Source: bauwion
