In the combustion of common fuels, what is the major source of boiler heat loss?

• A. Heat loss in the flue gases
• B. Heat lost to the surrounding environment
• C. Heat absorbed by the boiler body
• D. Heat loss during fuel preparation

Answer: (A)

In the combustion process of common fuels, the major source of boiler heat loss is primarily through the flue gases. During combustion, not all the energy produced is converted into usable heat; a significant portion of this energy is carried away by the flue gases as they exit the boiler. This heat loss can occur due to incomplete combustion, the temperature of the flue gases being elevated, and the specific heat capacity of the gases.

Understanding this concept is crucial for optimizing boiler efficiency. By minimizing heat losses in the flue gases, operators can improve the overall thermal efficiency of the boiler system, recover more usable heat, or incorporate heat exchangers or economizers to capture and reuse some of this lost heat. Addressing flue gas heat loss is fundamental for achieving energy efficiency and reducing operational costs in HVAC systems.