Which three sprinkler system types might be used in unheated spaces?

• A. Antifreeze, Dry and Pre-Action
• B. Wet Pipe, Deluge and Foam
• C. Deluge, Dry and Dry
• D. Wet Pipe, Pre-Action and Foam

Answer: (A)

In spaces that aren’t heated, the main concern is keeping sprinkler piping from freezing while still protecting against fire. Antifreeze systems use a glycol-based solution in the piping, which resists freezing and allows operation in cold areas. Dry pipe systems keep the pipes pressurized with air or nitrogen and only fill with water when a sprinkler head is activated, so there isn’t water sitting in the lines that could freeze. Pre-action systems require a trigger (like detection) before water enters the piping, reducing the chance of water damage and allowing the system to be configured in a way that mitigates freezing risk in unheated spaces. Together, these three approaches address freeze risk and potential water damage, making them suitable choices for unheated spaces.