What type of sprinkler temperature is required for a sprinkler installed 2 ft above a heating duct?

In the context of sprinkler systems, the temperature rating of a sprinkler is crucial for ensuring that it activates at the appropriate time in response to a fire. When a sprinkler head is installed near heat sources such as heating ducts, the environment around it can be significantly warmer than the typical room temperature.

For a sprinkler installed 2 feet above a heating duct, the risk of elevated temperatures from the duct necessitates a sprinkler with a temperature rating that accommodates these conditions. Intermediate temperature sprinklers are designed to activate at a higher temperature than normal sprinklers, making them suitable for installations where ambient heat is a concern.

Normal temperature sprinklers are typically used in standard conditions without significant heat sources nearby. High temperature sprinklers are suited for areas where even higher activation temperatures are necessary, such as industrial applications. Low temperature sprinklers are designed for cooler environments.

Thus, an intermediate temperature sprinkler is the correct choice for this scenario as it ensures that the sprinkler will not inadvertently activate due to the heat from the duct, while still being appropriately responsive to a legitimate fire situation.