Interaction of Sprinklers with Smoke and Heat Vents

Abstract

There has been an ongoing controversy about the use of sprinklers and smoke/heat vents together, and dozens of position papers have been published over the decades. This paper reviews 13 experimental studies that have some relevance to the claims posed for and against the combined use of sprinklers and smoke/heat vents. These studies are used to evaluate the positive and negative claims that have been made with regard to the combined use of sprinklers and smoke/heat vents. Three of the studies investigate the use of smoke/heat vents alone. Four investigations include sprinklers, but do not include roof vents. Three of these are test series in which perimeter vents were used in the test facility, and the fourth included sprinklers, a partial draft curtain, and no smoke/heat vents. Four test series included sprinklers, smoke/heat vents, and draft curtains, but utilized spray or pool fires which were not subject to extinguishment by the sprinklers. Four test series included sprinklers, smoke/heat vents, draft curtains, and used Class A fuels which were subject to extinguishment. The studies of smoke and heat venting used in conjunction with sprinklers show clearly that venting does not have a negative effect on sprinkler performance. Experimental studies have shown that venting does limit the spread of products of combustion by releasing them from the building within the curtained compartment of fire origin. This improves visibility for building occupants and firefighters who need to find the seat of the fire to complete fire extinguishment. Limiting the spread of smoke and heat also reduces smoke and heat damage to the building. In the event that sprinklers do not operate, venting remains a valuable aid to manual control of the fire. The experimental studies have shown that early vent activation has no detrimental effects on sprinkler performance and have also shown that current design practices are likely to limit the number of vents operated to one and vents may in fact not operate at all in very successful sprinkler operations. Design practices should move to methods that assure early operation of vents, and vent operation should be ganged so that the benefit of roof vents is fully realized. Sprinkler design with vents and draft curtains needs to take full account of draft curtains as obstructions. Curtains should be placed in aisles rather than over storage.