Gas Fitter Practice Test

How many heat exchangers does a condensing furnace typically have?

1. One heat exchanger

2. Operates without a heat exchanger

3. Two heat exchangers

4. Condensate drain and one exchanger

The correct answer is: Two heat exchangers

A condensing furnace typically has two heat exchangers. The first heat exchanger is used to extract heat from the combustion gases, which allows the furnace to reach higher efficiency levels by utilizing the latent heat of condensation from the exhaust gases. Through the process, water vapor in the exhaust cools and condenses, releasing additional heat that is then captured and used to warm the air being circulated throughout the space. The second heat exchanger is often found within the design of the unit to help further transfer heat to the air, ensuring that the furnace operates efficiently and effectively. This two-heat-exchanger design is integral for maximizing energy use and minimizing energy costs while providing comfort in heating applications. Therefore, accurately recognizing the role and number of heat exchangers is essential for understanding how condensing furnaces achieve high-temperature efficiencies.