Technical Standards and Safety Authority (TSSA) G3 Practice Exam

What is the temperature rise in a forced warm air furnace?

1. The temperature difference between the outdoor air and the return air

2. The temperature difference between the supply air and the return air

3. The temperature difference between the outdoor air and the supply air

4. The temperature difference between the return air and the flue gas

The correct answer is: The temperature difference between the supply air and the return air

The temperature rise in a forced warm air furnace is defined as the temperature difference between the supply air and the return air. This measurement indicates how much the air is heated as it passes through the furnace before being distributed into the living spaces. In a forced warm air system, return air from the space is drawn into the furnace where it is heated and then sent back into the home as supply air. By calculating the difference between these two air temperatures, you can assess the efficiency of the heating system and its ability to warm the air effectively. A higher temperature rise typically signifies that the furnace is functioning well in terms of heat generation. Understanding this concept is crucial for maintaining and troubleshooting heating systems, as it helps gauge whether the furnace is distributing adequate heat based on the desired indoor comfort levels.