ABSTRACT
Including those slated in residential occupancies, over 90% of all sprinkler systems installed today are wet-pipe systems. But not all building interiors are climate-controlled. Rising energy costs have led many to consider leaving portions of their buildings unheated. When this occurs, the only fire protection system options available are dry-pipe, preaction, heat tracing, or antifreeze. The traditional antifreeze system has been defined as “A wet-pipe system that contains an antifreeze solution and is connected to a larger wetpipe system that it uses for a water supply. It supplies automatic sprinklers to protect small unheated areas.”1 Where the unheated area is large, it is generally understood that the most economically viable alternative is to augment the wet-pipe system with an auxiliary dry-pipe system to protect the area subject to freezing temperatures.
