When gypsum materials are exposed in plenums, the air temperature must not exceed _______ degrees F.

When gypsum materials are exposed in plenums, the air temperature must not exceed _______ degrees F.

• A. 125
• B. 350
• C. 212
• D. 100

Answer: (A)

Plenums are air-handling spaces where heat from equipment can raise the temperature of exposed materials. Gypsum materials used in these spaces have a specified maximum exposure temperature to prevent degradation of the facing paper, loss of fasteners or adhesives, and to preserve fire and smoke performance. The standard limit is 125 degrees Fahrenheit, so keeping the air in the plenum at or below this temperature helps ensure the gypsum installations stay within their rated performance and don’t become a hazard. Higher temperatures (like 350 F) or irrelevant limits (such as 212 F or 100 F) do not align with the rated use of gypsum in plenums.

Plenums are air-handling spaces where heat from equipment can raise the temperature of exposed materials. Gypsum materials used in these spaces have a specified maximum exposure temperature to prevent degradation of the facing paper, loss of fasteners or adhesives, and to preserve fire and smoke performance. The standard limit is 125 degrees Fahrenheit, so keeping the air in the plenum at or below this temperature helps ensure the gypsum installations stay within their rated performance and don’t become a hazard. Higher temperatures (like 350 F) or irrelevant limits (such as 212 F or 100 F) do not align with the rated use of gypsum in plenums.