Cfm To Btu/Hr Calculator

BTU/h Formula:

\[ BTU/h = CFM \times 1.08 \times \Delta T \]

BTU/h (BTU per hour):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the CFM to BTU/h Formula?

The CFM to BTU/h formula calculates the heat transfer rate in British Thermal Units per hour based on airflow in cubic feet per minute and temperature difference. This is essential for HVAC system design and analysis.

2. How Does the Calculator Work?

The calculator uses the standard formula:

\[ BTU/h = CFM \times 1.08 \times \Delta T \]

Where:

\( CFM \) — Airflow in cubic feet per minute
\( \Delta T \) — Temperature difference in degrees Fahrenheit
\( 1.08 \) — Conversion constant (accounts for air density and specific heat)

Explanation: The constant 1.08 is derived from the specific heat of air (0.24 BTU/lb-°F) and the density of air (0.075 lb/ft³) at standard conditions, multiplied by 60 minutes per hour.

3. Importance of BTU/h Calculation

Details: Accurate BTU/h calculation is crucial for proper HVAC system sizing, energy efficiency analysis, and ensuring adequate heating or cooling capacity for spaces.

4. Using the Calculator

Tips: Enter CFM value in cubic feet per minute and temperature difference in °F. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What does the constant 1.08 represent?
A: The constant 1.08 combines air density (0.075 lb/ft³), specific heat of air (0.24 BTU/lb-°F), and minutes to hours conversion (60 min/hour).

Q2: When is this calculation typically used?
A: This calculation is commonly used in HVAC design for sizing heating and cooling equipment, ductwork design, and energy analysis.

Q3: What are typical CFM values for residential systems?
A: Residential systems typically range from 400-2000 CFM depending on home size, with 1 CFM per square foot being a common rule of thumb.

Q4: Does this formula work for both heating and cooling?
A: Yes, the formula works for both heating and cooling applications, as it calculates the heat transfer rate regardless of direction.

Q5: Are there limitations to this calculation?
A: This assumes standard air conditions. For high altitude, high humidity, or extreme temperature applications, additional corrections may be needed.