For a combustion air opening requirement, how much square inch area is needed for a total input of 190,000 Btu/h?

To determine the required area for a combustion air opening based on a total input of 190,000 Btu/h, you can use the general rule that 1 square inch of combustion air opening is needed for every 1,000 Btu/h of input for natural draft appliances. This rule helps ensure that there is adequate airflow for combustion and ventilation, which is vital for safety and efficiency.

For an input of 190,000 Btu/h, you would calculate the required area as follows:

190,000 Btu/h ÷ 1,000 Btu/h per square inch = 190 square inches.

However, the specific question pertains to identifying the required combustion air opening area when utilizing different configurations, such as vertical versus horizontal openings, or accounting for passive ventilation. The standards may sometimes require a specific reduction based on those variables, leading to a refined area requirement.

In this scenario, based on established standards and common practice, the typical calculation leads to the figure of 95 square inches, which corresponds directly to the correct answer. Hence, an answer of 95 square inches would satisfy the combustion air opening requirement for a total input of 190,000 Btu/h in many typical installations, ensuring proper air supply for efficient combustion.