Btu To Cfm Calculator

BTU to CFM Formula:

\[ CFM = \frac{BTU}{1.08 \times \Delta T} \]

Air Flow (CFM):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the BTU to CFM Calculation?

The BTU to CFM calculation converts British Thermal Units per hour (BTU/hr) to Cubic Feet per Minute (CFM) of air flow, based on temperature difference. This is essential for HVAC system design and airflow requirements in heating applications.

2. How Does the Calculator Work?

The calculator uses the BTU to CFM formula:

\[ CFM = \frac{BTU}{1.08 \times \Delta T} \]

Where:

\( CFM \) — Cubic Feet per Minute (air flow rate)
\( BTU \) — British Thermal Units per hour (heating capacity)
\( \Delta T \) — Temperature difference in degrees Fahrenheit
\( 1.08 \) — Constant factor for air density and specific heat

Explanation: The formula calculates the required air flow (CFM) needed to transfer a specific amount of heat (BTU/hr) given a temperature difference between supply and return air.

3. Importance of Air Flow Calculation

Details: Proper air flow calculation is crucial for HVAC system efficiency, ensuring adequate heating capacity, maintaining comfort levels, and preventing system overload or inefficiency.

4. Using the Calculator

Tips: Enter BTU value in BTU/hr, temperature difference in °F. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What does the 1.08 constant represent?
A: The 1.08 constant accounts for the specific heat of air (0.24 BTU/lb-°F) and air density (0.075 lb/ft³), converted to appropriate units for the calculation.

Q2: When is this calculation typically used?
A: This calculation is commonly used in HVAC design for determining air handler sizing, ductwork design, and heating system requirements.

Q3: What is a typical ΔT for heating systems?
A: Typical temperature differences range from 15°F to 40°F for residential heating systems, depending on the application and system design.

Q4: Can this formula be used for cooling calculations?
A: While similar principles apply, cooling calculations often use different constants and considerations due to moisture removal and different air properties.

Q5: How accurate is this calculation for real-world applications?
A: This provides a good estimate for standard conditions, but actual system design should consider factors like altitude, humidity, and specific equipment efficiency.