What is the free area required for each of the two combustion air openings for a fuel oil burner rated at 1.25 GPH?

For a fuel oil burner rated at 1.25 gallons per hour (GPH), the free area for combustion air openings is determined based on the manufacturer's guidelines and commonly referenced standards in the HVAC industry. Each fuel oil burner requires sufficient combustion air to ensure optimal performance and efficiency while preventing the production of harmful byproducts.

In this specific scenario, the calculation for determining the free area required considers factors such as the rate of fuel oil consumption and relevant building code requirements. The standard requirement is typically expressed in square inches of free area per fuel input, ensuring a proper air-to-fuel ratio for complete combustion.

For a burner rated at 1.25 GPH, the specified free area is approximately 175 square inches for each combustion air opening, leading to a total of 350 square inches when considering two openings. This requirement facilitates adequate airflow necessary for the burner to operate safely and efficiently. Thus, the selection of 175 square inches aligns with these calculations and is vital for achieving the right conditions for combustion.