Sprinklers are a multi-billion dollar industry with commercial systems costing anywhere between $400,000, to $15 million. Any changes to legislation pertaining to the installation of such systems can potentially lead to lost business.
Due to issues raised here, it is likely that some will refer to the Canadian journal to justify the use of a sprinkler on glass, system. This data is invalid for the following reasons:
1- While the (Canadian) report states that the test was a positive pressure test, testing parameters were not carried out as we (in Australia) require under AS1530.4, and there is no attempt made to address the effect of these differences. 2- The report does not detail how to install the glass wall as tested. Items like glass clearances to the frame (for thermal expansion clearances), coverage area for the beading and the fixing method (so the glass won’t slump out of the frame) and many other issues that go with Fire Testing a Prototype glass wall are not given in the report. 3- There are no doors tested in the system. To date, there is no technical justification or ‘engineering judgement’ that can justify the use of fire doors in sprinklered glass walls. The 2014 reissue of ESR-2397 (AC385) prohibits the use of ANY openings.
Installing a top-notch suppression system and assuming it will activate early enough to extinguish or stop the spread of fire is not the answer for eliminating fire rated doors and windows. Since sprinklers are an “active” system, they require several steps to activate for them to work properly. Sprinklers need to produce enough water pressure to activate, without this constant pressure they won’t activate.
Water pressure is only one of many such factors. Water supply can be accidentally turned off, sprinkler heads can be accidentally painted over and if the system isn’t maintained the whole setup is useless. Are you beginning to see the danger of relying exclusively on an active fire protection system?
Sprinklers can be reliable and have saved lives and property, however they should not be a replacement for more “passive” systems such as fire rated glass that can provide a degree of fire protection without depending on any outside factors. Additionally, a sprinkler system only works when the water coats the entire glass surface consistently. If blinds, décor, furniture or even doors that are left open stop the water protecting the glass, the entire system is useless.
Advocates of fixed window sprinkler systems suggest working around the problem by simply making a written requirement that blinds, and combustible items are far enough away from the glass, so they do not get in the way of the water from the sprinklers.
If the sprinklers extinguish the fire, it won’t matter if glass breaks. We have raised several potential red flags regarding sprinklers. But let us suppose for a moment that there has been a fire and the sprinklers have worked exactly as intended. The fire is put out even before building occupants have the chance to evacuate. Would it really matter if the glass in some of the windows and doors had been broken in the process? The answer is a definite yes. One of the primary concerns in extinguishing a fire is smoke, since most fire related deaths are caused by smoke inhalation. Sprinklers create an enormous volume of smoke. If glass has broken, the smoke will be free to travel throughout the building, which means it can still threaten life safety even after the fire is extinguished.