What type of sprinkler head is required if it is located above a heat duct within a 7' radius?

In situations where a sprinkler head is positioned above a heat duct, the key consideration is the potential for elevated temperatures, which can result from the heat emitted by the duct. Therefore, a high temperature head is necessary because it is designed to withstand and operate effectively in environments where temperatures can be significantly higher than those encountered under typical conditions.

High temperature heads are equipped with a thermal element that activates at a higher temperature threshold, ensuring they do not inadvertently discharge when the ambient temperature near the heat duct rises, such as when heat is flowing from the duct itself. This is crucial for maintaining effective fire protection and ensuring that the sprinkler system activates when it is genuinely needed, rather than prematurely due to the heat from the duct.

In this context, both standard and low temperature heads would not be suitable as they are designed to operate at lower activation temperatures. An extra high temperature head, while capable of handling even higher temperatures, is generally used in more extreme environments than a typical ceiling-mounted sprinkler above a heat duct would necessitate. Thus, the high temperature head is the appropriate choice for this specific scenario.