1. What is Combustion Air Calculation?

The combustion air calculation determines the amount of air required for proper combustion of natural gas. Adequate air supply is essential for efficient and safe operation of gas-fired appliances, ensuring complete combustion and preventing the production of dangerous byproducts.

2. How Does the Calculator Work?

The calculator uses the combustion air formula:

Where:

• \( BTU/hr \) — British Thermal Units per hour input
• \( 11 \) — Cubic feet of air required per 1000 BTU
• \( 1000 \) — Conversion factor

Explanation: This formula calculates the cubic feet per hour (CFH) of combustion air needed based on the BTU input of the natural gas appliance.

3. Importance of Combustion Air Calculation

Details: Proper combustion air calculation is crucial for ensuring efficient fuel combustion, preventing carbon monoxide production, maintaining appliance efficiency, and complying with safety codes and standards.

4. Using the Calculator

Tips: Enter the BTU/hr rating of your natural gas appliance. The value must be greater than 0. The calculator will determine the required combustion air in cubic feet per hour (CFH).

5. Frequently Asked Questions (FAQ)

Q1: Why is 11 CFH per 1000 BTU used?
A: This value represents the typical air requirement for complete combustion of natural gas, accounting for the stoichiometric air-fuel ratio with additional excess air for safety.

Q2: What happens with insufficient combustion air?
A: Insufficient air can cause incomplete combustion, producing carbon monoxide, reducing efficiency, and creating safety hazards.

Q3: Does this calculation include ventilation air?
A: This calculation provides combustion air requirements only. Additional ventilation air may be needed for appliance cooling and space ventilation.

Q4: Are there different requirements for other fuel types?
A: Yes, propane, oil, and other fuels have different air requirements due to varying chemical compositions and combustion characteristics.

Q5: How does altitude affect combustion air requirements?
A: At higher altitudes, air density decreases, requiring larger volume of air to provide the same mass of oxygen for combustion.