What type of sprinkler is specifically designed for dry systems in untreated attics?

The dry-type sprinkler is specifically designed for use in dry pipe systems, which are often installed in environments like untreated attics where temperatures can drop below freezing. These sprinklers allow the system to remain dry until activation, thus preventing the water supply from freezing. When the heat from a fire activates the sprinkler, it opens and allows pressurized air to escape, which in turn releases the water from the pipes to extinguish the fire.

This design is crucial in applications where maintaining a water-filled pipe system would be impractical, such as in unheated spaces. The dry-type sprinkler's unique construction and operation make it ideal for preventing ice formation, which could cause system failures during a fire event.

In contrast, standard response and quick response sprinklers are generally used in wet systems, where water is constantly present, and are not designed for the specific challenges posed by untreated attics. Wet-type sprinklers are filled with water at all times, which does not suit environments where freezing is a concern.