What does "stack temperature" indicate?

Stack temperature refers specifically to the temperature of the flue gases as they exit the boiler. Monitoring this temperature is critical for assessing the efficiency of the combustion process within the boiler. High stack temperatures may indicate that the boiler is not efficiently transferring heat, which can lead to increased fuel consumption and operational costs.

By contrast, the temperature of water in the boiler, ambient air temperature, and steam temperature represent different points in the boiler system and do not provide insights into the combustion efficiency or the effectiveness of heat transfer like stack temperature does. Therefore, understanding stack temperature is essential for boiler operators to optimize performance, ensure proper functioning, and comply with emission regulations.