Fire System in Apartment Blocks (a real case)
Development was built in the early 90’s and despite the fact that legislation in force at the time provided for such, no fire alarm system was installed.
The development comprised of 12 separate common areas giving access to a total of 66 apartments.
(illustrative image)A typical common area was as follows:
- Two flights of external entrance steps which led to the main entrance door of the common area at 2nd storey level. Underneath the external entrance steps was the electrical meter room/switch room. Once you entered the common area door you were in a 1.5m wide lobby with an apartment on the left and on the right and in the middle was the stairs to the next level where you had 4 apartment entrance doors around a semi octagon shape landing.
In order for the automatic detection devices, such as heat and smoke detectors, to provide the intended protection, care must be taken in selecting the level of coverage to be used. A common misconception is that “strategically” placing a few smoke or heat detectors in a particular area of a building (such as smoke detectors in an apartment building hallway) provides good “early warning protection.” It should be obvious that if the fire is remote from the detector location, the fire will not be detected “early.”
The requirement of the recently granted building Fire Cert called for an L3X Fire Alarm System to be installed. There was a definite argument to go with a wireless addressable fire alarm system due to the fact that it was a finished building and the challenge involved in carrying out cable runs taking into account the disruption to tenants, achieving the required sound levels and leaving the finished product aesthetically pleasing. It is important to note that there were a variety of different apartment internal layouts. Some with long Z-shaped corridors and some duplexes. Achieving the necessary sound levels was not straightforward by any means and in most cases would involve more than one sounder within most of the apartments. A sound level survey was carried out to establish this.
Once quantities were agreed on, we submitted a very detailed quotation, a fully transparent breakdown of the costs involved for both a wireless system and a hardwired system. With the quantities involved and high cost of wireless equipment not only did the initial installation costs come in one third more expensive than the hardwired system, but this combined with the higher maintenance of the wireless system including replacement batteries over its expected lifetime, made the hardwired system the definite option.
In order to comply with the requirements of I.S. 3218 Standard and also make the installation aesthetically pleasing it was decided to run PVC trunking with the fire rated cable fixed within trunking with fire rated cable cleats drilled and screwed to the wall at the relevant distances. This not only secured the cable in compliance but also secured the trunking. All the trunking joints were accurately mitred.
There are some steps we have to take before and during the fire alarm system installation, make sure that your fire safety company complies with all standards and requirements required by Irish legislation.
The L3X main building fire alarm system was complimented by the installation of an LD2 domestic smoke alarm system in each individual apartment, The project was completed on time with the minimum inconvenience and the finished installation was found to be very satisfactory by all concerned.
CFSG is a one stop shop that supplies all your Fire Safety needs, email us info@cfsg.ie or call us 01 295 7540. CSFG operates a nationwide service backed up by a 24 hour call monitoring facility.
