1. What Is CFM Calculation For Duct Size?

CFM (Cubic Feet per Minute) calculation for duct size is essential in HVAC systems to determine the airflow capacity through ducts. It ensures proper ventilation and efficient system performance.

2. How Does The Calculator Work?

The calculator uses the CFM formula:

Where:

• \( Velocity \) — Air velocity in feet per minute (ft/min)
• \( Area \) — Cross-sectional area of the duct in square feet (sq ft)

Explanation: The formula calculates the volume of air flowing through a duct per minute based on the speed of the air and the size of the duct.

3. Importance Of CFM Calculation

Details: Accurate CFM calculation is crucial for designing efficient HVAC systems, ensuring adequate ventilation, maintaining indoor air quality, and optimizing energy consumption.

4. Using The Calculator

Tips: Enter velocity in ft/min and area in sq ft. Both values must be positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a good CFM for ductwork?
A: The ideal CFM depends on the size of the space, but typically ranges from 400-2000 CFM for residential systems.

Q2: How does duct size affect CFM?
A: Larger ducts can handle higher CFM with lower velocity, while smaller ducts require higher velocity to achieve the same CFM.

Q3: What is the typical air velocity in ducts?
A: Residential systems typically maintain velocities between 600-900 ft/min, while commercial systems may go up to 2000 ft/min.

Q4: How do you calculate duct area?
A: For rectangular ducts: width × height. For circular ducts: π × (diameter/2)².

Q5: Why is CFM important in HVAC design?
A: Proper CFM ensures adequate air distribution, maintains comfort levels, prevents system strain, and improves energy efficiency.