Fire & Safety: multiple choice

Kidde Safety discusses how electrical wholesalers can advise their customers on today’s complex selection criteria for domestic smoke, heat and CO alarms.

BS 5839-6:2013 reviews various types of alarms and which is best to alert occupants of fire, while avoiding nuisance alarms that could result in disabling the alarm.

Ionisation smoke alarms are sensitive to small smoke particles from rapidly burning, flaming fires but less so for smouldering fires and smoke that has travelled some distance.

Optical smoke alarms are sensitive to larger particles from smouldering fires and less prone to nuisance alarms than their ionisation equivalents, especially from steam.

Heat alarms respond more slowly to fires than smoke alarms but are less likely to give nuisance alarms and require less maintenance: they must always be interlinked with smoke alarms.

BS 5839-6:2013 therefore recommends optical smoke alarms for Circulation Spaces (Halls and Landings) and Bedrooms; heat alarms for Kitchens and Garages; and ionisation alarms for Living Rooms.

Wireless interconnection

Professionally installed, hard-wired, interconnected smoke and heat alarms are Building Regulation requirements for new-builds, extensions and some alterations. But they are equally applicable to most existing properties as well. Interconnection simply enables all the alarms to sound when one is triggered by a fire.

But there may be both practical and visual implications for avoiding disruptive interconnect cabling between alarms. Here, wireless interconnection is an ideal solution, for example using Kidde’s Slick Wireless Alarm Base accessory.

This simply replaces the standard base plate and is used to interconnect Slick smoke or heat alarms, with each alarm separately powered from a lighting circuit nearby. It can also be used with Kidde’s Remote Test & Hush switch to communicate with a Slick alarm that might otherwise be difficult to access.

This is particularly useful for older or disabled residents, or properties with particularly high ceilings. Alternatively, a wired remote test and hush unit is available and this can also be used with Kidde’s Firex range.

Simplified installation is also a consideration to keep costs down and manufacturers now offer systems designed with this in mind. For example, Kidde’s Slick fast-fit system utilises a separate base plate that can be installed and its integral terminal block wired at first fix. Then, near completion, the alarm simply slides onto the base plate hinge flap and locks into place by default. This feature also makes maintenance or replacement simpler.

Energy saving

The market’s growing interest in energy saving products and lower running costs for homeowners and tenants is focusing on safety products too. In response, the latest generation of Firex optical and ionisation smoke alarms, and heat alarms, manufactured and supplied exclusively by Kidde, now offers a much lower mains consumption than previously. Firex alarms cost less than £1 per year to run – a major benefit for tenants.

The Firex range also offers greater choice with options for long-life lithium battery backup, alongside the usual loose battery and integral rechargeable battery versions. This innovation ensures reliable backup throughout the whole alarm life, without the need to change batteries, at a much lower price than rechargeable products.

Urgent solutions

Mains alarms with backup are a Building Regulation requirement and recommended for most existing housing and all rented properties under BS5839 Part 6. But there may still be urgent situations where battery smoke alarms can provide immediate protection – particularly where no alarms are present at all. Here, Kidde’s 10Y29 optical smoke alarm, with a full 10-year guarantee covering both the alarm and sealed-in lithium battery, can be quickly and easily installed by the maintenance team.

The continuing toll of deaths and illness resulting from carbon monoxide poisoning incidents from various fuels and types of combustion appliances, including cookers, makes a strong case for fitting CO alarms in all homes. For peace of mind, the long-term reliability of any CO alarms installed is paramount – particularly with the current presence of non-compliant products in the market.

Kitemarked CO alarms

Just as with smoke alarms, an established manufacturer with a reputation for quality, supported by third party accreditation, is essential. For example, all Kidde CO alarms, whether hard-wired or battery, are BSi Kitemarked and comply with the latest edition of BS EN 50291:2010. Kidde also manufactures its own sensors, allowing tighter quality controls to be applied. They use safer, environmentally friendly de-ionised water rather than acid-based electrolytes as well.

All the Regulations and the British Standard are unanimous in allowing either mains or battery-only CO alarms. Battery alarms should incorporate a battery designed to operate for the working life of the detector, such as Kidde’s self-contained 10LLCO and 10LLDCO carbon monoxide alarms, which enjoy a full 10-year guarantee covering both the alarm and sealed-in lithium battery. The CO sensors – the key component – are actually tested throughout a 10-year period or longer.

Extra features

The latest generation of CO alarms offers extra features, such as the ‘End-of-Life/Fault’ LED found on Kidde’s 10LLCO and 10LLDCO units. These units also have an alarm sounder designed to protect occupants and installers’ hearing when testing, with an initial lower level of sound being generated. The 10LLDCO model also has a digital display to provide early warning of intermittent and low levels of carbon monoxide. A ‘Peak Level’ button can also help identify CO problems occurring when the property is not occupied.

Hard-wired mains with backup carbon monoxide alarms are also popular, such as Kidde’s 4MCO and 4MDCO models. These can be interconnected with each other and also the company’s Slick or Firex ranges of smoke and heat alarms using the ‘Smart Interconnect’ feature to create a comprehensive system for whole home protection. Crucially, the CO alarms have different, distinct alarm sounder patterns for carbon monoxide and fire, supported by different display messages on the digital model.

So, without the need for any further operation of the system (such as remote switches), Smart Interconnect automatically alerts occupants of the specific hazard that confronts them. This allows them to respond quickly, making the right choice from the very different alternative actions for either fire or the presence of carbon monoxide. Using Smart Interconnect, Kidde CO alarms act as sounders for the smoke/heat alarm system as well as warning of carbon monoxide. This is particularly useful in bedrooms where occupants may not be awoken by landing smoke alarms.