1. What is AC Duct Size Calculation?

AC duct size calculation determines the appropriate diameter of air conditioning ducts based on airflow (CFM) and velocity. Proper duct sizing is essential for efficient HVAC system operation and optimal airflow distribution.

2. How Does the Calculator Work?

The calculator uses the duct size formula:

Where:

• \( CFM \) — Cubic Feet per Minute (airflow rate)
• \( Velocity \) — Air velocity in feet per minute

Explanation: The formula calculates the required duct diameter based on the relationship between airflow rate and air velocity.

3. Importance of Proper Duct Sizing

Details: Correct duct sizing ensures efficient HVAC operation, proper airflow, balanced system performance, and energy efficiency. Undersized ducts can cause airflow restrictions while oversized ducts can lead to energy waste.

4. Using the Calculator

Tips: Enter CFM (cubic feet per minute) and velocity (feet per minute). Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical velocity range for AC ducts?
A: Residential systems typically use 600-900 ft/min for supply ducts and 500-700 ft/min for return ducts.

Q2: How does duct size affect system performance?
A: Proper duct size ensures optimal airflow, reduces noise, improves efficiency, and prevents system strain.

Q3: What factors should be considered besides CFM and velocity?
A: Duct material, layout, number of bends, and static pressure should also be considered for complete duct design.

Q4: Can this calculator be used for both round and rectangular ducts?
A: This formula calculates equivalent round duct diameter. For rectangular ducts, additional conversion is needed.

Q5: What are common CFM requirements for different room sizes?
A: CFM requirements vary based on room size, insulation, and climate, but typically range from 1 CFM per square foot for cooling.