Fire doors are designed to prevent the spread of smoke, flames and toxic gases throughout a building in the event of a fire. However, when a fire door is held open, fire, smoke and toxic gases can quickly pass through the building, blocking escape routes and endangering lives.
Building regulations require that, a building’s fire doors must therefore be self-closing to ensure the door closes to act as a barrier to stop the fire from spreading.
Due to the level of protection a fire door provides, the placement and weight of the doors is often restrictive for example in a care home setting for residents, for pupils in a school or for guests in a hotel.
It is recognised that in these cases it is necessary to hold fire doors open for practical reasons. In this instance the fire door must have a device installed to release the door, so that it will close upon activation of the fire alarm system.
Holding open fire doors legally
Making sure fire doors are closed when the fire alarm sounds is extremely important. The British Standard 7273-4:2015 Code of Practice for the operation of fire protection measures – Part 4: actuation of release mechanisms for doors, gives guidance on the installation, commissioning and maintenance of fire door holding systems. The system/hardware used to hold the doors open should be CE marked under the Construction Products Regulations, using the relevant European standard; EN 1155.
Fire door retainers, also known as fire door holders, use a magnet to hold open heavy fire doors that will release in the event of a fire. Stand-alone door retainers are suitable for doors that already have a closing device fitted, however fire door closers with a built in hold open function are also available.
Depending on the installation and level of protection required, there are a variety of fire door retainers readily available which react to different triggers in the event of a fire.
Hard wired fire door retainers
Geofire is the largest manufacturer in the UK of hard-wired fire door holding magnets. Hard wired fire door retainers are used all over the world and are ideal for new buildings as they have a direct wire connection to the building’s fire detection system. In a normal condition, power (usually 24 V dc) is supplied to the door retainers so that they can hold the doors in an open position. When a fire is detected by the fire panel, power is cut releasing the doors so that they can close. A fault in the wiring or power supply to the door retainers will cause them to fail safe and release the doors.
Hard-wired fire door holders are available in many shapes, sizes and finishes to suit all applications. UL listed versions are available from Geofire encased in steel or thermoplastic polymer housing.
Radio controlled fire door retainers
Radio controlled fire door retainers are triggered wirelessly by radio waves from a controller connected to the building’s existing fire panel or interface unit. As minimal wiring is needed, these are often used for fitting into large, existing buildings but still offer high levels of protection. The Salamander system manufactured by Geofire is suitable for installations BS7273-4 critical actuation (category A), the highest fire standard in the UK. A typical radio controller unit can manage up to 99 fire door holders and closers within a 50 meter range, with the option to add boosters extending the range by 50 meters per booster.
These systems are installed by an approved, trained professional as a site survey has to be carried out prior to installation.
Sound activated fire door retainers
Sound activated fire door retainers react to the noise of the fire alarm and some devices can learn the sound of the building’s specific fire alarm, so they will only release when the alarm sounds. This is a cost effective solution as there is no need for wiring to a fire panel. The Agrippa sound activated fire door holder, in particular, records the sound of the building’s fire alarm onto the device during installation. This means that the holder will only close the fire door if the specific alarm tone sounds.
Sound activated fire door retainers are battery powered and can be installed quickly and easily. They are wire-free, so installing them won’t affect a building’s infrastructure.
Using door closers as hold open devices
Most fire doors are fitted with a standard door closer which creates a mechanism to allow the door to be opened and closed. This does not hold or automatically close the fire door.
Fire door closers can be used as a mechanism to enable fire doors to be held open (often at any angle if ‘free-swing’), to ease access whilst ensuring that the door will automatically close in the event of a fire.
Fitting a fire door closer eliminates the need for a standard closer and a fire door holder. As long as the closer has a ‘free-swing’ mode, it will hold the door open in any position. A fire door closer will also make heavy fire doors feel light and easy to move, where as a fire door holder will not; the door will be held back to the wall, fully opened.
A fire door closer may be more suitable in environments where it is necessary to have the door slightly open to reduce feelings of isolation (care homes or residential properties) or where users find internal fire doors heavy and hard to open.
Fire door closers can be bought in radio controlled or sound activated versions.
Innovators of fire technology
Geofire has been designing and manufacturing electromagnet fire door holders and closers for 45 years from its factory in County Durham. Established in 1972, the company is still continuing to invest in research and development to be able to offer cost effective and innovative fire technology.
Andy Collinson, CEO at Geofire, said: “What makes Geofire stand out from the rest is that all of our products are designed and manufactured in-house by our team of experienced engineers. We continually invest in research and development to be able to offer cost effective and innovative fire technology solutions.
“At Geofire we have a solution available for all installations, whether it is a new build using our hard-wired products, a noisy environment where radio would be more suitable (Salamander) or, where an acoustic solution is required to close the fire doors upon hearing the sound of the fire alarm (Agrippa).
“Our distribution network is continuously growing around the world and we are always interested to hear from fire safety specialists and distributors wanting to know more about our range of products.”
For more information, go to www.geofire.co.uk