In response, a team from the Royal College of Art and Imperial College Business School set up Plumis in 2008, to design better fire suppression systems. This has resulted in the creation of the Automist SmartScan, a smarter, cheaper alternative that can be installed or retrofitted into any building, uses less water than a traditional sprinkler system and therefore causes less water damage. One of the main drawbacks with installing a sprinkler system is that you either need a very large water tank or you need to increase the size of the water main to provide the amount of water needed – up to 89 litres per minute.
Yusuf Muhammad, design director at Plumis, says: "One of the boundary conditions that we set for the brief was that we’d like to limit the amount of water it uses to 5.6l/min, which means it can be installed in most buildings."
Another benefit of reduced water consumption is that the system can run off standard mains, meaning it only needs a pump, around the same size of a power shower’s. The pump unit provided with Automist SmartScan is around the size of a PC tower unit (365 x 240 x 178mm) and weighs 6kg, so it can fit in a cupboard or under the stairs. Also, it uses a tenth of the water of a traditional sprinkler system by emitting a fine mist rather than a deluge, reducing water damage.
"The biggest issue we currently have is that every spray heads needs a pump," says Muhammad. "But this year, we’re working on a version that connects one pump with up to four heads."
Muhammad and his team experimented with many configurations, but found it difficult to get a uniform blanket of water mist that could tackle fires regardless of their location. This led to what Muhammad describes as the critical piece of innovation: putting an infrared pyrometer in the spray head.
"The default conditions required to set off a traditional sprinkler system is a maintained 57°C on the ceiling," he says. "This means that when a sprinkler system goes off, the core of the fire is about 200 to 300°C. But, with a scanning head it’s very easy to precisely locate the fire."
A heat sensor is mounted in the centre of a ceiling in a room, with the spray head mounted on the wall at a height of 1.2 to 1.3m. When heat is detected by the ceiling mounted sensors, it triggers the spray head to begin scanning the room using its pyrometer. Once located, the sprinkler head can begin to spray a vertical blade of water mist at the fire.
Each spray head has a range of 6m, which is enough to cover one floor of a regular-size house.
The added benefit of mounting a spray head on the wall rather than on the ceiling, is that the water mist doesn’t have to be forced through the hot layer of air above the fire, which can cause evaporation. Instead, it can be directed right at the fire’s base.
"We’ve designed the size of the water blade so it doesn’t matter where the fire is in the vertical plane. Even if the fire starts directly under or over the spray head, the blade will emit enough mist to tackle it," says Muhammad. "The other thing that we stumbled across is something called the Coanda effect."
The Coanda effect
The Coanda effect is a phenomenon in which a jet flow, in this case the blade of water mist, attaches itself to a nearby surface and runs along it even if the surface curves away from the initial direction. It means, even if a fire is located along the wall upon which the spray head is mounted, the blade will still be able to reach it.
By using sensors, Plumis has found a further level of innovation. The system has the potential to be used as a connected building device whereby the sensors could be used to detect heat loss from a building. Equally, the sensors could be useful in other fire safety applications.
"We’re looking at how you can use the temperature scan to find an obstruction and then inform the user," Muhammad says. "Information from the sensors could also be transmitted to the emergency services, so they know what type of fire they will be battling before they get to the scene. Or, it could be used to detect people trapped in a particular room."
Data collection is a growing market and each SmartScan system has a ‘black box’ that records data from the fires it combats. That information is sent to the cloud and becomes part of a growing fire ‘database’ where, through updates, the Automist SmartScan systems can learn how to combat specific types of fire more efficiently.
"Currently, the units don’t contain these auxiliary devices, we need to find where the biggest need is first," Muhammad says. "We’ve been speaking to insurance companies to find out what information will be useful. Plus, the technical guys in the lab are looking at how we can improve our fire performance in an emergency, which is what makes the platform so exciting."
Exciting is not a word often used to describe sprinkler systems, but Plumis wants to bring innovation, connectivity and intelligence to what has been an established technology. The SmartScan also allows for a greater amount of open space, a popular trend in current building design.
Automist SmartScan has been tested to the same standard as traditional sprinkler systems, yet is more efficient, causes less water damage on activation, and critically is cheaper to install. While sprinkler systems have, no doubt, helped save the lives of millions, Automist offers a 21st Century intelligent alternative that is set to add further benefit the life saving technology.