A complete fire protection system based on wireless smoke detectors

Affordable, easy to install, without requiring a central alarm panel

Requirements of a smoke detection system for an office or home

and integration with access control and burglar alarm 

A fire protection system should

  • be fail safe: many fires start in and electrical installation, causing a power failure. The fire protection system should continue to work without general power. Cables connecting smoke detectors or sirenes to a fire protection panel could burn before alarming. The interconnection should be wireless or by fire resistant cabling.
  • have a loud alarm, alarming everyone in the building: people mostly get killed by the smoke of a starting fire. Sleeping people do not wake up from smoke, so the alarm must wake up everyone.
  • allow you to mute the sirens and quickly locate the source of the alarm. Loud sirens tend to disable people to think straight. Once people are notified, the sirens should be temporarily hushed. The system should help people find the triggered detector.
  • connect to the access control system: on fire alarm, all doors should unlock allowing an easy exit, or allowing help or emergency services to enter. An integrated solution like Loxone could also switch on all lights if power is still available, to make navigating in the smoke easier. 
  • send a remote alarm, preferably by phone call, to allow someone to investigate the alarm, reset the alarm when false, or call the emergency services. 


Our solution

As usual, we select solutions for small businesses, offices, shops, homes, and choose one that is affordable, good quality vs price, simple to install and operate, and integrates well with other solutions.

Smoke detectors

Principle

The optical smoke detectors detect a fire early, communicate the alarm to other smoke detectors, and all smoke detectors sound their internal siren (83dB at 3m) to make sure everyone in the building is notified or woken up. The sirens can be silenced all at once, except for the one that triggered the alarm, so you can easily find that location.  The sirens can also be activated for other purposes like a burglar alarm
.

Wireless communication

Up to 12 detectors can be interlinked wirelessly + up to 8 additional devices in 1 zone. (However, we have a client where it is working with 15 detectors, 1 interface, 2 alarm buttons). Unlimited 'zones' can be created. Every detector acts as a repeater, so a large distance can be covered. Any detectors can also be connected by a simple wire (2 wires) if needed. The wireless communication is only active on alarm or on test, and it is not dependant on a working wifi signal. 

Battery powered >10 years

The smoke detectors are powered by an internal battery that lasts over 10 years. All detectors, the communication and the internal sirens continue to work when there is a power failure. You do not need a separate backup battery system. You also do not need to care about replacing batteries for 10 years. Installation is really simple: you can just attach the readers to the ceiling without needing to install any cabling, which saves you money. Even a smoke detectors in a storage room at some distance outside can be linked. The system can easily be extended later by adding a new smoke dtector, CO detector, alarm button, control panel or interface in a zone, and have the other devices learn the added device.

Wireless interface

A separate wireless interface is available for integration with other systems (e.g. opening/closing doors, switching lights on, remote notifications):

  • 3 outputs (relays contacts)
    • smoke alarm
    • CO alarm
    • fault alarm (sensor or battery fault)
  • 1 input can be activated by closing a contact (connecting 2 wires) and has multiple function: it can be used to:
    • test the detectors and communication
    • on alarm: silence the sirens to identify the triggered detector, and reset the alarm
    • activate all sirens for other purposes like a burglar alarm. or connecting to an existing alarm panel

The Wireless interface can be fully KNX enabled by adding in this interface and some simple circuitry.

Comparison to other systems

A traditional fire alarm is much more expensive to purchase, install and maintain. However, you still need it for large installation or buildings with central management of separate units. For small businesses, offices, shops, houses, the proposed system makes more sense and is generally accepted by the local fire department.

KNX smoke detectors are expensive (>250 euro) and require KNX kabling and configuration. They allow more advanced and individual control, however, this does not add much useful functionality.

Loxone Air smoke detectors do not include a loud siren. Only the triggered detector beeps. To have a fail safe alarm, you must add sirens and a backup battery power protection for the Loxone Miniserver and the sirens. The detectors need to be in range of an Air extension.

Google Nest smoke detectors communicates/operates between detectors in a similar way as our proposed solution, but are to be controled via a separate app over Wifi. We however want all functionality to be available in 1 visualisation (Loxone app or a KNX visualisation). Integration can be done via the API over Wifi, however, this is currently too complicated. We will however explore this furher in case the device adds more useful functionality like acting  as a presence detector. 

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