26 Dec Different end users have different demands
One of the most exciting aspects of working within the fire sector and fire engineering is providing bespoke solutions and building assurance to a diverse range of building types and occupancies – all requiring protection from the effects of fire writes Peter Stephenson, Business Development Director, Warringtonfire.
When considering fire safety in secure buildings, my first thoughts focused on the storage of, and fire protection requirements for, high value assets such as precious metals, minerals and valuable documents. On further consideration, I was compelled to include other secure buildings such as museums and historic buildings, banks and prisons, which all have security requirements but different end-user experiences and requirements.
A museum may store or have on display priceless artefacts and there is a balance between public access, secure and safe storage of these valuables, and the need to have a suitable and effective package of fire safety measures based on the hazards and risks identified in the relevant building. All these factors should be assessed and included in the building fire strategy.
Fire is a major threat to all buildings, whether a new, existing or heritage site, and we have seen the tragic results when museums and their collections have been involved in a fire scenario. It can destroy or irreparably damage historic collections and structures housing them within minutes. The provision of effective fire protection should include prevention, detection, and suppression of fire to minimize the impact of fire and its potential to spread.
Implementation of museum fire prevention and protection policies and plans, fire-safe practices and design, and the installation of automatic museum fire protection systems and portable fire extinguishers are critical to life safety and the overall building protection.
When considering historic structures, many are extremely vulnerable to fire due to their design, building materials and components. Without automatic fire protection, furnished historic structures and their contents are at serious risk of damage or destruction from fire.
Museums and historical buildings generally have several large exhibition rooms with high ceilings. A key consideration is the height of the room (and the large volume of air) which will cause the concentration of any fire-related aerosol to be strongly diluted. This demands high sensitivity smoke detection, which can be best provided by an Aspirating Smoke Detection (ASD) system. ASD systems can detect even the smallest aerosol concentrations and offer the ideal solution for early fire detection in exhibition halls in modern museums.
However, in historically sensitive buildings the installation of such a system is often not a practicable solution, due to the impact on the authenticity and fabric of the building. In such cases an alternative solution could be to use a combination of sensitive wireless smoke detectors and linear smoke detectors.
In the event of a fire, the highest priority must be given to alerting and evacuating all building occupants at risk. A fire protection system is needed that guarantees rapid, reliable fire detection and activates both the alarm devices and the relevant fire control installations.
Early warning of a fire in historical buildings and museums is essential; not only for saving lives, but also for the protection of cultural heritage and protection of valuable assets. However, unnecessary evacuation activities due to false alarms must be avoided.
Fire Risk Assessment
A robust and on-going risk assessment process should be adopted and implemented as secure buildings often have environmental controls to ensure room cleanliness with temperature and air quality monitoring and control. Even when the necessary structural fire protection measures (such as effective compartmentation) and organisational measures (such as the strict enforcement of a no smoking ban, etc.) have been taken, the fire risk will still remain high – in spite of the fact that the probability of a fire occurring may be very low. The dominant factor here is the enormous damage that could be caused to extremely valuable assets and to the room itself.
To protect very valuable or delicate exhibits from damage or theft, they are often displayed in showcases. Large, glass display cabinets should also be protected by an ASD system. In this way, the slightest emissions can be detected, which may indicate the overheating of some material inside the showcases.
Ensuring appropriate alarm notification is provided is also an important consideration as exhibition visitors may also include hearing impaired persons. Optical alarming devices such as beacons (or sounder-beacons) should also be installed, in addition to the standard sounders.
In many cases, the installation of an automatic extinguishing system will not be permitted, due to the impact on the ornate ceilings or due to general aesthetic considerations, However, the selection of an extinguishing system should be discussed with the relevant stakeholders as salvage plans for artefacts can provide valuable input into the overall fire strategy and selection of fire protection systems.
An archive may be a dedicated building, such as a national or state archive. However, many museums and art galleries will also contain storage vaults, used to store and catalogue innumerable objects that are not currently being displayed. There are also several independent art storage warehouses, which often store valuable artefacts for famous museums and art galleries.
Archives and storage vaults may house various types of object; depending on the building itself (e.g. cash, precious metals, manuscripts, paintings, stored documents, works of art, archaeological finds, etc.). These are risk areas that need to be especially well protected, particularly from the danger of fire.
The high concentration of flammable and very valuable artefacts implies that any incipient fire must be detected as early as possible and effectively extinguished, without the extinguishing agent used causing any further damage to the objects stored in such rooms. As archives often consist of multiple rooms, the fire protection infrastructure should also ensure that a fire in one room cannot spread to an adjoining room or to any other part of the building. Innovative fire protection systems, including oxygen depletion systems, could form part of the overall fire protection package within the building fire strategy.
Good results have been achieved by using a mixture of nitrogen together with a fine water mist. The nitrogen effectively reduces the oxygen content of the room atmosphere and extinguishes the fire. The water mist provides additional cooling and eliminates any danger of re-ignition, without causing damage to the stored artefacts.
As archives are generally dedicated rooms in buildings and may not be visited daily, early detection and suppression of incipient fires in these rooms also ensures that smoke and fire cannot spread throughout the building and become a life-threatening danger.
Due to the high concentration of valuable assets stored in archives and storage vaults, these facilities present several exacting requirements relating to early detection and fire suppression. Even a fire starting in a partially enclosed area (e.g. manual mobile shelving) must be detected early. This is also true for fire suppression; the extinguishing system must be designed in such a way that even a fire in the furthermost corner of the room will be extinguished quickly and reliably. In addition to the high reliability of the individual functions, such as detection, alarming, control activation and effective extinguishing, they must all be coordinated to work with one another in an optimal manner. Only in this way can fire damage be kept to an absolute minimum.