The NSA-004A operates fanlessly up to an ambient temperature of approx. 35°C (freestanding).
Above this temperature, an internal fan switches on, which is regulated depending on the temperature and enables operation up to an ambient temperature of 50°C.
The fans draw air through air inlets in the front and rear of the unit. The air leaves the device through an opening in the rear.
Caution
Do not place the devices next to a heat source, e.g. a radiator. The ventilation openings of the devices must never be blocked.