1. What is the Combustion Air Formula?

The Combustion Air Formula calculates the required air volume in cubic feet per hour (CFH) for natural gas combustion based on BTU input. This is essential for proper ventilation and combustion efficiency in gas-fired appliances.

2. How Does the Calculator Work?

The calculator uses the combustion air formula:

Where:

• \( BTU Input \) — Total heat input in British Thermal Units per hour
• \( 10 \) — Conversion factor for natural gas combustion
• \( 1,000,000 \) — Scaling factor for CFH calculation

Explanation: The formula provides the combustion air requirement in cubic feet per hour based on the BTU input of the gas appliance.

3. Importance of Combustion Air Calculation

Details: Proper combustion air calculation is crucial for ensuring efficient and safe operation of gas appliances, preventing incomplete combustion, and maintaining indoor air quality.

4. Using the Calculator

Tips: Enter the BTU input of your gas appliance in BTU/hr. The value must be greater than 0 for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why is combustion air important for gas appliances?
A: Adequate combustion air ensures complete combustion, prevents carbon monoxide production, and maintains appliance efficiency.

Q2: What are typical BTU inputs for common appliances?
A: Water heaters: 30,000-50,000 BTU/hr, Furnaces: 60,000-120,000 BTU/hr, Stoves: 15,000-40,000 BTU/hr per burner.

Q3: Does this formula apply to all fuel types?
A: This specific formula is for natural gas. Propane and other fuels have different air requirements.

Q4: What happens with insufficient combustion air?
A: Incomplete combustion can occur, producing carbon monoxide, reducing efficiency, and potentially damaging the appliance.

Q5: Are there building code requirements for combustion air?
A: Yes, most building codes specify minimum combustion air requirements based on appliance BTU ratings and room volume.