What is true regarding draft tests for condensing furnaces?

In the context of condensing furnaces, the performance of draft tests is critically linked to their operational characteristics. Condensing furnaces operate with positive pressure, which can affect the way flue gases are expelled and exhaust systems are designed.

Because they are designed to maintain a certain pressure differential that effectively directs flue gases outside, the requirement for draft testing becomes less critical compared to other types of furnaces that operate under negative pressure. Positive pressure helps in preventing backdrafts or the entrance of outside air into the combustion chamber, which can lead to safety concerns like flue gas spillage. Consequently, it is generally accepted that draft tests are not required for these systems under normal operating conditions, as their design inherently mitigates many risks associated with draft failures.

Understanding the operational mechanics of condensing furnaces and the significance of positive pressure aids in recognizing the rationale behind the lack of requirement for routine draft testing for these particular models.