Andy Speake of Aico details the benefits multi-sensor alarms can bring social housing providers, particularly from a cost saving perspective
The first mains powered domestic multi-sensor was launched to the smoke alarm market in 2014 as a means of providing the best response to all fire types and reducing false alarms, making alarm specification and installation simpler in the process. Since then, a range of multi-sensors have entered the domestic market and have been growing rapidly in popularity, notably in the social housing sector.
What is it?
A typical multi-sensor comprises both optical and heat sensors within the same alarm unit, although other variations do exist (Aico provides a multi-sensor designed for the kitchen with heat and carbon monoxide sensors, for example). Multi-sensors differ in design and their ability to detect fires and identify false alarms can therefore vary. The most basic models can have limited cross evaluation of the sensor values, while some of the market’s most sophisticated devices – in order to determine the nature of the potential fire – feature advanced algorithms to assess the variation in values from each sensor.
Those more sophisticated devices are extremely effective at providing a quick response to both slow smouldering and fast flaming fires while remaining more impervious to kitchen fumes and contamination which are so often the cause of false alarms. Research carried out by the Building Research Establishment (BRE), in conjunction with the Fire Industry Association, has highlighted the benefits of multi-sensors when it comes to reducing false alarms. The BRE 2018 Briefing Paper – ‘The performance of Multi-Sensors in fire and false alarm tests’ – reports on the findings of its testing of 35 different optical heat multi-sensors and estimates that potentially 38.1 per cent of observed false alarms could have been reduced if multi-sensors had been present. Grove Community Housing Association in Northern Ireland replaced its existing smoke alarms with Aico multi-sensors and heat alarms in more than 80 per cent of its properties. Denis Bleakley, Grove Community Housing Association general manager, explains the decision: “We liked the Multi-Sensor technology to reduce false alarms for us and our tenants, which we found was backed up by BRE research.” Since the new Aico alarms have been installed, Denis states that he has not had any false alarms reported.
Multi-sensors are more sophisticated than single sensor alarms and are priced accordingly – around 15 per cent more per unit. However, you are getting two alarm types in one and, with the more sophisticated models such as our own, there are complex algorithms interpreting the signals to get a better understanding of what is really happening in the immediate environment. With multi-sensors, you are getting the best of both worlds: improved protection and reduced costs when you take into account the financial implications of reduced false alarms that multi-sensors bring.
Using our own extensive experience and market knowledge, along with insights from a range of Registered Social Landlords across the UK, we have run some figures and they make for interesting reading. Based on 10,000 properties where smoke alarms are fitted to the minimum category of protection, LD3, we estimate a potential saving of £101.5k on call out costs when compared to fitting an optical alarm. That saving more than doubles when alarms are fitted to the medium protection category LD2, which is increasingly being adopted following recent changes to BS 5839-6:2019 (the code of practice for the design, installation, commissioning and maintenance of fire detection and fire alarm systems in domestic premises) and changes to Scottish Legislation.
Aico estimates that switching to quality multi-sensors can reduce call out rates by an incredible 90 per cent, resulting in a maintenance cost saving which offsets the initial higher purchase cost and still provides an overall saving. Social housing providers are very much in tune with this. Watford Community Housing has installed Aico multi-sensors and accessories into two 16 storey tower blocks. David Wright, surveying manager at Watford Community Housing explains: “We believe the products deliver the best in safety for our tenants. We are also aware of what is required from a maintenance point of view, helping us to minimise the time we spend in the properties. We were looking to address the issue of false alarms and we believe that the dual aspect of this product will help to reduce nuisance alarms.” South Cambridgeshire District Council is also using Aico mains powered multi-sensors, along with heat and carbon monoxide alarms, in its 1,400 sheltered housing properties.
“It is imperative to specify the right product for the right situation” states Eddie Spicer, M&E surveyor for the Council. “Obviously, cost is a major factor and with the introduction of the latest technologies in the multi-sensor, the lack of false alarms has paid dividends with lower call out rates and nuisance alarm activations.” The multi-sensor may only have been in the domestic market for a mere five years, but what an impact it has made during that short time! Social housing providers have been quick to realise the benefits in terms of improved tenant safety and a reduction in false alarms and overall costs. With increasing evidence of the benefits of multi-sensors and the move to LD2 smoke alarm systems which require a higher level of protection, involving more alarms per property, the rise of the multi-sensor looks set to continue.
Andy Speake is national technical manager at Aico