Why is soot a concern for the operation of a cad cell?

Soot is a concern for the operation of a cad cell because it can block light transmission. The cad cell, or cadmium sulfide cell, relies on detecting the infrared light produced by a flame to determine whether the burner is ignited and running properly. If soot accumulates on the cell or in the combustion area, it can obstruct the light reaching the cad cell, causing it to give false readings. This blockage can lead the burner to shut down unnecessarily or fail to operate correctly, which can hamper the system’s reliability and overall efficiency.

Understanding the role of soot highlights the importance of proper maintenance and cleaning of the combustion chamber and cad cell to ensure optimal functioning of the HVAC system. Soot impacts other aspects of the combustion process, but the specific relationship between soot and light transmission is crucial for the cad cell's operation.