The new regulation UNI 11988 replaces the previous standard UNI ISO 7240-19. The aim is to standardise design and maintenance criteria nationwide, ensure reliable performance of the EVAC systems in critical situations and support designers, installers and maintainers in meeting fire safety standards.
What has changed?
Recommended emergency voice signal sound levels at listening height
NB: in UNI CEN TS 54-32 the maximum sound level in all areas is 120 db(A)
Prescriptive design method (requirements to be met within an ADA)
Seated listeners should be considered at a height of 1.2 m above the floor and standing listeners at a height of 1.6 m above the floor.
Security levels of the EVAC system
Backup power supply
The previous standard ISO 7240-19 stated that in the event of a main power source failure, the emergency power source must comply with the requirements of local regulations. In the absence of local regulations, the emergency power source must supply s.s.e.p. for 24 h in the resting condition and for 30 min in the voice alarm condition. Performance with an emergency power source must not result in a decrease in speech intelligibility below the required values and a decrease in the audible alarm signal below 6 dB below the required sound level.
With the new criteria laid down in the UNI 11988 regulation, it is common practice to provide auxiliary mains power supplies such as an uninterruptible power supply or generators that do not comply with EN 54-4, in order to keep electrical systems operational during a mains supply failure. If the voice evacuation system is connected to such an auxiliary power supply, this does not invalidate the requirement of EN 54-16 to provide one or more back-up power supplies complying with EN 54-4, but may be acceptable reduce standby time, after a risk assessment.
If the emergency management plan specifies that the building must be evacuated following a failure of the primary power supply, backup power must be able to operate the EVAC system in the voice alarm condition for at least 30 min or for twice as long as the evacuation time specified in the emergency management plan, whichever is longer.
4Evac systems by Bosch
With the entry into force of the new UNI 11988:2025 standard, it therefore becomes essential to adopt technologically advanced, reliable solutions that comply with recent provisions. The systems of 4Evac by Bosch reflect precisely these characteristics, offering a high-performance platform for sound evacuation management. Thanks to their modular architecture and guaranteed speech intelligibility even in complex environments, the 4Evac by Bosch devices are a safe and ideal choice for aplications in the public sphere, industrial e commercial.
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