Wireless protection

The introduction of wireless interconnect, mains-powered smoke alarms has a number of important implications. There are safety, financial, logistical, compliance and timescale implications – in fact wireless interconnect technology has the capability to change everything.

BS 5839 Part 6, in its amended 2004 form, recognises the existence of and makes special allowances for the new technology. Installers will now no doubt feel more comfortable using wireless interconnect, but its full benefits may not yet be fully appreciated.

Although the security industry has been using wireless alarms successfully for years, it’s only in 2004 that the technology has been available to fire safety professionals, with the introduction of Radiolink from Ei Electronics and Aico.

The technology

Wireless interconnect technology basically removes the need to hard wire alarms together. When one alarm detects smoke it sends out a radio signal, setting off all the other alarms on the system almost instantaneously. All the alarms are coded together during installation, so there’s no chance of false alarms being triggered by other systems.

The safety implications are fairly obvious. It’s well recognised that it’s highly desirable to interconnect all the alarms in a home. After all, people asleep upstairs behind a closed door may simply not hear the alarm downstairs going off – vital minutes that could have been used for escape are lost. However, while it’s desirable to interconnect alarms, it’s usually a very expensive process for the end-user because of the labour involved and the redecoration that may be required. Some customers, constrained by budget, may not be able to include it as a feature.

Cost savings

Wireless interconnect technology has strong financial implications. The bases may cost more than conventional versions because of the radio transceiver technology they contain, but this extra capital cost can be more than offset by savings in labour, decoration and on raw materials such as trunking and cabling. It’s worth pointing this out to customers.

These cost savings can be beneficial to the installer as well, because they might be able to install more alarms per premises or fit systems into more premises within a fixed budget. The savings may make the difference between whether or not a specifier can afford interconnection on a premises.

Cost savings achieved could also be used to enhance safety in other ways. A better grade of alarm may be selected, for example, one with ten-year Lithium cell back-up. Alternatively the money saved could be spent on initiatives such as the installation of carbon monoxide alarms.

When it becomes desirable to add more alarms to an existing system, it could prove more economical and convenient to replace the existing system with a new wireless interconnect one, rather than hard-wiring in an extension. This is especially true with systems where the alarms might be due for replacement shortly anyway.

It’s true to say that with new build properties or those undergoing total renovation, wireless technology may not be the best solution financially. The best financial advantage comes when installing into an existing occupied property where other extensive electrical work is not required.

System benefits

Wireless technology has implications for tenant compliance too. Many tenants, especially the elderly, may be reluctant to have a mains-powered, hard-wired system fitted because of the upheaval it causes and the unsightly trunking.

With wireless interconnect systems, installers spend far less time on the premises. There’s no need to pull up floorboards and there’s no trunking stretched between the alarms.

Wireless technology also has significant implications for protecting flats and houses in multiple occupation (HMO). It can be used to interconnect between, as well as within, properties.

In hard-wired installations it’s necessary to cross property boundaries with mains cables in order to interlink alarms. This could pose an electrical safety risk if people working in the dwelling were unaware that there are two mains power supplies.

With wireless interconnect technology, each alarm in the system can be connected to a local power supply. The interconnect between the individual alarms is provided by the radio signal, therefore overcoming this risk.

In flats and HMOs where interconnection between dwellings is not required, but a connection to the communal areas is for early warning purposes, it is easy to provide a simple, effective system. Simply code the alarms in each flat separately, then code the alarms in the communal areas with, say, a heat alarm in the individual dwellings.

In this way, if a nuisance alarm should occur within one of the dwellings it will not affect the other residents. If a real fire has occurred, the heat alarm in the dwelling will operate the communal system – and alarms in all other dwellings – when sufficient heat has been generated.

Wireless interconnect technology also has implications for applications where the protection of remote areas or outbuildings would ideally be brought under one system and for HMO communal systems planning and buildings where, for example, a warden might need to be notified of an alarm sounding in a remote property.

When planning installations using wireless technology you can juggle all these factors to the best advantage for clients and yourself. Clients might find interconnection affordable for the first time, cover more homes or increase the level of coverage or quality of alarms in individual properties.

Wireless interconnect technology offers a more flexible approach to planning. With the availability of the products and its recognition by BS 5839 Part 6: 2004, it is worth becoming familiar with the technology and its benefits.

Neil Perdell is technical services manager with Aico.