Btu Hr To Cfm Calculator

BTU/hr to CFM Conversion Formula:

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

CFM (cubic feet per minute):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is BTU/hr to CFM Conversion?

The BTU/hr to CFM conversion calculates the cubic feet per minute of air flow required to transfer a specific amount of heat energy (BTU/hr) given a temperature difference. This is essential for HVAC system design and sizing.

2. How Does the Calculator Work?

The calculator uses the conversion formula:

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

Where:

\( BTU/hr \) — British thermal units per hour (heat transfer rate)
\( \Delta T \) — Temperature difference in degrees Fahrenheit
\( 1.08 \) — Constant derived from air density and specific heat
\( CFM \) — Cubic feet per minute (air flow rate)

Explanation: The formula converts heat transfer rate to air flow rate based on the temperature difference the air undergoes during heating or cooling.

3. Importance of CFM Calculation

Details: Accurate CFM calculation is crucial for proper HVAC system design, ensuring adequate air flow for heating and cooling loads, energy efficiency, and occupant comfort.

4. Using the Calculator

Tips: Enter BTU/hr (heating or cooling capacity) and 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 is derived from the specific heat of air (0.24 BTU/lb-°F) and air density (0.075 lb/ft³) at standard conditions.

Q2: Can this formula be used for both heating and cooling?
A: Yes, the formula works for both heating and cooling applications, as it calculates air flow based on heat transfer and temperature difference.

Q3: What are typical CFM requirements for residential HVAC?
A: Residential systems typically require 350-400 CFM per ton of cooling capacity, but this varies based on specific design requirements.

Q4: Does this calculation account for humidity?
A: This basic calculation assumes dry air. For precise calculations involving humid air, additional factors like latent heat should be considered.

Q5: How accurate is this conversion for real-world applications?
A: The conversion provides a good estimate for standard conditions. For precise engineering applications, additional factors like altitude and air density variations should be considered.