Gas Heat ESCO Practice Exam 2025 - Free Gas Heat ESCO Practice Questions and Study Guide

Nitrogen is an inert gas that makes up a large percentage of the air we breathe. In the context of combustion, when nitrogen is present in the combustion air, it can act as a heat sink and absorb some of the heat released during the combustion process. This absorption of heat by nitrogen reduces the overall combustion temperature, which in turn can lead to a decrease in combustion efficiency. Therefore, the statement that nitrogen reduces combustion efficiency by absorbing heat is correct.

Option A is incorrect because nitrogen does not enhance combustion efficiency by facilitating heat transfer; instead, it has a cooling effect on the combustion process.

Option B is incorrect as nitrogen does have an effect on combustion, as explained above.

Option D is incorrect because nitrogen does not increase the rate of combustion; in fact, it can have the opposite effect by reducing the combustion temperature.