EWIS Systems

A EWIS (Emergency Warning and Intercommunication System) is an enhanced system for fire alarm alerting and evacuation control in larger or more complex buildings. Instead of the whole building receiving the (evacuation) alerting signal simultaneously, the premises are instead subdivided into multiple evacuation zones. In response to signals from the fire alarm system, the EWIS system controls a zone-by-zone staged/phased evacuation according to a pre-programmed scheme. 

As with “all out” evacuation, the EWIS system generates the standard “rising whoop” evacuation signal and plays a voice message with evacuation instructions. With an EWIS these messages can be customized for various types of installations, and multi-lingual capabilities are usually available. In addition, a preliminary “Alert” tone, with separate verbal message, can be played to zones that have not (yet) reached the evacuation stage. In a high-rise, for example, this would typically mobilise evacuation (floor) wardens. 

A EWIS system is also designed to enable either the fire service or a designated building warden to take manual control of the evacuation, including directing Public Address (PA) messages to all or selected evacuation zones.

An (optional) Emergency Intercommunication (warden telephone) system allows building wardens or fire-fighting personnel to communicate with the master evacuation control panel to coordinate evacuation efforts. 

The rationale behind audio evacuation systems is, though conventional fire alarm notification devices alert occupants of a building to the presence of an emergency, they do not provide detailed information to the occupants, such as evacuation routes or instructions. Nor do they allow occupants in the greatest danger to have unimpeded access to escape routes. 

EWIS systems usually permit multiple messages. For instance, "non fire" messages can be programmed for situations such as a hazardous material spill, gas leaks, security breaches, etc. 

They can also be used to provide non-emergency building Public Address facilities.

Historically, the New Zealand Building Code Compliance Documents designated EWIS systems as “Type 8” Voice Evacuation Systems and they were mandated for new buildings primarily in healthcare, high-rise, and large crowd occupancies (cinemas, stadiums, shopping malls). This is no longer the case and such occupancies are now expected to be subject to specific fire engineering design. 

Under NZS 4512:2010, EWIS systems are required to comply with AS 2220 part 1: 1989 and to be installed to AS 1670.4: 2004.