G2 Gas Fitter Practice Exam

If the return and supply air plenum are both located on the top of the furnace, what type of furnace is it?

1. High Boy

2. Low Boy

3. Side Boy

4. Vertical Furnace

The correct answer is: Low Boy

A furnace where both the return and supply air plenums are positioned at the top is identified as a Low Boy furnace. This design is specifically engineered for applications where there are spatial limitations, often found in areas with low ceilings. The "low boy" configuration allows for efficient airflow and ensures that the unit can effectively deliver heated air into the space without requiring significant vertical clearance. The design features of a Low Boy furnace include a shorter vertical profile, making it a perfect fit for smaller spaces while still providing the necessary heating. The placement of the plenums at the top helps facilitate optimal airflow dynamics, allowing for better distribution of heated air into the living space. This is particularly important in ensuring that the system operates effectively without putting undue strain on the equipment due to poor air circulation. In contrast, other types of furnaces, such as the High Boy, Side Boy, or Vertical Furnace, have different configurations that would not fit the scenario described. Understanding these distinctions is crucial for selecting the appropriate furnace type based on the specific requirements of a space.