What type of sprinkler head is typically used in the unheated portion of a freezer?

In the context of fire protection systems, especially in environments like freezers, it is important to understand the operational characteristics of various sprinkler heads. The correct answer highlights that open head sprinkler systems are used in the unheated portions of a freezer because they allow for the immediate discharge of water when activated. This type of system is particularly useful when protecting areas that experience extremely low temperatures, as they do not become affected by freezing conditions, unlike other types of heads.

Open head sprinklers are designed to work in conjunction with a deluge system, which means that when a detected fire triggers the system, all sprinkler heads discharge water simultaneously. In settings like a freezer, this rapid response can effectively suppress fire by providing immediate water coverage.

In contrast, other types of sprinkler heads, such as closed head systems, are designed to prevent water flow until individual heads are activated by heat, which may not be beneficial in environments where freezing could restrict functionality. Dry heads, on the other hand, are generally used in areas prone to freezing but may not be the conventional choice for unheated portions, as they are specifically designed to prevent water from standing in the drops until needed. Pre-action heads incorporate a combination of both dry and wet systems but are typically more complex and not specifically