If 1 cubic foot of natural gas is 1000 Btuh, what is the ratio of total air?

The ratio of total air required for combustion in natural gas appliances can be derived from the understanding of combustion principles. Natural gas requires a specific air-to-fuel ratio to combust completely and efficiently.

When burning natural gas, it is essential to have the proper amount of air to ensure complete combustion, which helps in minimizing pollutants and maximizing energy output. For every 1 cubic foot of natural gas, it typically requires around 10 to 15 cubic feet of air for complete combustion under standard conditions, with the specific requirements varying slightly depending on the appliance and its configuration.

In this question, if 1 cubic foot of natural gas provides 1000 Btuh, it points to the energy content and combustion efficiency. A higher ratio, such as 30, often assumes specific scenarios where the combustion process is optimized for particular conditions or equipment that may operate less efficiently, needing more air to complete the combustion process fully.

This understanding of the combustion process and typical air requirements in real-world applications leads us to conclude that the ratio of total air for optimal combustion and efficiency under typical conditions would favor the higher end of the available options, hence the choice indicating a ratio of 30 is deemed the most appropriate.