CSLB Class B General Contractor's License Practice Exam

What happens when the combustion air supply is restricted in a confined space?

1. Complete combustion occurs

2. Lower efficiency of heating

3. Increased carbon monoxide generation

4. No impact on the heating system

The correct answer is: Increased carbon monoxide generation

When the combustion air supply is restricted in a confined space, it can lead to increased carbon monoxide generation. This occurs because combustion processes require a specific amount of oxygen to burn fuel efficiently. When there is insufficient air supply, incomplete combustion takes place, which means fuel is not fully burned. As a result, byproducts of combustion, such as carbon monoxide, can accumulate. Carbon monoxide is a toxic gas that can pose serious health risks if inhaled. This is particularly concerning in confined spaces where the gas can concentrate. The need for adequate ventilation becomes critical in such environments to ensure safe operation of heating systems and to prevent the hazardous buildup of carbon monoxide. Completing combustion would not occur under restricted air conditions, and significant heating efficiency losses would be expected, not just a lower efficiency. Hence, this situational understanding emphasizes the importance of proper air supply in maintaining safe and efficient combustion processes.