1. What is the CFM to BTU Formula?

Definition: This calculator estimates heat transfer in BTUs per hour based on airflow (CFM) and temperature rise.

Purpose: It helps HVAC professionals and engineers determine heating/cooling capacity requirements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat transfer rate (BTU/h)
• \( CFM \) — Airflow in cubic feet per minute
• \( \Delta T \) — Temperature difference (°F)
• 1.08 — Constant combining air density and specific heat

Explanation: The formula calculates how much heat is being added or removed by the airflow based on temperature change.

3. Importance of BTU Calculation

Details: Proper BTU calculation ensures correct sizing of HVAC equipment for efficient operation and comfort.

4. Using the Calculator

Tips: Enter the airflow in CFM and temperature rise in °F. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does the 1.08 constant represent?
A: It combines the density of air (0.075 lb/ft³) and specific heat (0.24 BTU/lb°F) with unit conversion factors.

Q2: Can this be used for cooling calculations?
A: Yes, use the temperature drop instead of rise for cooling applications.

Q3: What's a typical CFM for residential systems?
A: Typically 350-400 CFM per ton of cooling capacity (12,000 BTU/ton).

Q4: How accurate is this formula?
A: It's accurate for standard air conditions at sea level. Adjustments may be needed for high altitudes.

Q5: What if I know kW instead of BTU?
A: 1 kW = 3,412 BTU/h - you can convert after calculation if needed.