BRITISH STANDARD FOR WATERMIST

BRITISH STANDARD FOR WATERMIST

A new draft British standard (DD 8458) for watermist fire protection systems has just been published, nearing completion, covering industrial/commercial and domestic/residential applications.

The new document for fire protection in domestic and residential premises has now been completed by the technical committee with very few issues needing to be addressed and only one of these being of a technical nature.  It has now has been submitted to the committee chairman for the final sign-off before publication.

The document has been written as a complement to the current BS9251 standard covering the use of sprinklers. The main factor that prevented misting systems from being compliant with BS9251 has been the standard’s restrictions on nozzle spacing and minimum flow rates of water.

These regulations are currently based on long-standing tried and tested historical data, which cannot be applied to water mist systems for two reasons:

• Similar historical data does not exist for misting systems
• All manufacturers of water mist systems have flow rates and pressures that are unique to them

Based on this it was felt that to produce a robust document, test protocols should be included to prove the effectiveness of a system before it could claim compliance. These criteria have now been added as an annex to the main document.

Ultra SS Fire Group Ltd aims to be the first company in the UK to carry out full scale testing to comply with these protocols.

Watch this space.......

Ultra Guard Wales Fire & Rescue

To watch the Ultra Guard water mist system in action is a fantastic experience, especially if you haven’t seen it before. As well as being an incredibly fast and effective method of fire suppression, it is also extraordinary how little water damage is left behind once the fire is extinguished. It certainly impressed the Wales Fire & Rescue service when we organised a demonstration at their fire house in Dolgellau, so much so that they have now decided to purchase these units.

Working closely with their Community Team Safety Manager Paul Scott, we set up a very realistic fire scenario, constructing a 4 metres square room containing a crib. Immediately this was set alight, the system sprung into operation.

• Within 25 seconds the smoke detector linked to Ultra Guard had detected the smoke from the crib and set up a 10-minute discharge of water mist.
• While the system was discharging, we turned Ultra Guard off at the mains to show how the system could operate just as effectively under its 7-day emergency battery power supply.
• Within seconds, the flames were out.
• While extinguishing the flames, the mist had also dampened the air within the room, preventing the fire spreading to other combustible materials.
• Additionally, the mist demonstrated its invaluable property of cleansing the air. Normally, any occupants in the vicinity of the fire would have to crawl out beneath the smoke level, but with Ultra Guard they can evacuate normally and without breathing difficulties. This is a tremendous safety asset.
•  After the 10 minute discharge was over, there were only a few smouldering embers left, which were extinguished a few minutes later by the moisture left in the air.

Live demonstrations are always invaluable for showing a system in operation. No matter how many facts and statistics you present, there is nothing to beat seeing a water mist system cope with a real fire hazard.

As well as safeguarding life and preventing the spread of fire, water mist minimises the very serious problem of water damage. Ultra Guard only discharges 11 litres of water per minute as compared with 100 litres per minute emitted by a conventional water sprinkler. The figures speak for themselves.

The 10 minutes of effective fire fighting conducted by Ultra Guard gives Fire & Rescue personnel time to arrive at an incident. As any professional fire fighter knows, time is of the essence and can make all the difference in preventing serious loss or personal injury.

Stirling Castle installation

Stirling Castle is well worth a visit. Dating back to the 12th Century, it stands high on a volcanic rock close to the site of the Battle of Bannockburn, where Robert the Bruce defeated the English army in 1314. Within the compound is James V’s Royal Palace, acknowledged as the finest Renaissance building in Scotland.

Historic Scotland is today’s guardian of the building and its many priceless historic treasures and today’s enemy is not armoured English knights but fire. However, fire protection in historic buildings can be a challenge, because water sprinklers can cause major water damage problems, especially with artefacts such as tapestries and paintings.

Fortunately, the gentler action of water mist fire protection is providing a solution, because the fire is smothered by wetting surfaces rather than soaking them. The minute droplets of water mist also bind with smoke particles, washing them down to floor level to drastically reduce smoke damage, one of the great secondary hazards of fire.

Historic Scotland saw this new technology as the solution for Stirling and selected Ultra SS, which has installed water mist systems in a number of historic buildings, including Blenheim Palace, to design and install the water mist system. We rose to the challenge and, in fact, the fire protection system we created for Stirling is unique, being a Low Pressure water mist system that displays High Pressure characteristics. This was what the project demanded and, Low Pressure systems being less expensive, kept us well within budget.

The opportunity to create this highly effective hybrid system came about because of the particular demands of the Stirling Project. The water for the fire suppression had to travel up a riser pipe to the top of the building to avoid damage to the fabric of the building by penetrating the walls.  This in turn created the opportunity for a remarkable configuration exclusive to Stirling.

The water coming out of the riser pipe is split so as to travel through loops of smaller pipes between 15mm and 20mm in diameter. So while this is basically a low pressure system, it offers high pressure characteristics.

For a historic building like Stirling the system is ideal. To cover a room 15m by 9m, a conventional water sprinkler would require 12 nozzles, whereas a water mist system can spray up to 25 square metres via a single discreet nozzle. Sprinklers will use 5 litres of water per square metre per minute, while water mist can provide the same level of fire suppression with just 1.6 litres per minute.

At no point has the installation compromised the aesthetic and historic character of the Castle, which made the project challenging and absorbing for us and our partners in Historic Scotland’s Stirling Project:

• Morris & Spottiswood (main contractors)
• Arthur MacKay (electrical contractors)
• Stewart Kidd, consultant (Loss Prevention Consultancy).

Incidentally, Stewart is currently producing a fascinating case history about the Project for future publication.