1. What is AC Duct Sizing?

AC duct sizing involves calculating the appropriate cross-sectional area for air conditioning ducts based on airflow requirements and velocity. Proper duct sizing ensures efficient airflow distribution and optimal system performance.

2. How Does the Calculator Work?

The calculator uses the duct sizing formula:

Where:

• \( A \) — Duct cross-sectional area (sq ft)
• \( CFM \) — Airflow rate (cubic feet per minute)
• \( V \) — Air velocity (feet per minute)

Explanation: This formula calculates the required duct area by dividing the airflow rate by the desired air velocity.

3. Importance of Proper Duct Sizing

Details: Proper duct sizing is crucial for maintaining adequate airflow, reducing energy consumption, minimizing noise, and ensuring even temperature distribution throughout the space.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is the recommended velocity for AC ducts?
A: Typical velocities range from 600-900 ft/min for main ducts and 400-600 ft/min for branch ducts, depending on noise considerations.

Q2: How does duct size affect system performance?
A: Undersized ducts increase resistance and reduce airflow, while oversized ducts can cause velocity issues and uneven air distribution.

Q3: What factors influence duct sizing?
A: Airflow requirements, velocity limits, duct material, system static pressure, and noise considerations all influence duct sizing decisions.

Q4: Are there different formulas for round vs rectangular ducts?
A: The basic formula remains the same, but additional calculations are needed to convert between equivalent round and rectangular duct sizes.

Q5: Should duct losses be considered in sizing?
A: Yes, friction losses and dynamic losses should be accounted for in comprehensive duct system design to ensure proper airflow delivery.