1. What Is CFM Calculation?

CFM (Cubic Feet per Minute) calculation determines the airflow rate needed for proper room ventilation. It helps in designing HVAC systems, ensuring adequate air exchange for indoor air quality and comfort.

2. How Does The Calculator Work?

The calculator uses the CFM formula:

Where:

• \( CFM \) — Cubic feet per minute (airflow rate)
• \( V \) — Room volume in cubic feet
• \( ACH \) — Air changes per hour

Explanation: The formula converts air changes per hour to cubic feet per minute by dividing by 60 minutes. This provides the continuous airflow rate needed to achieve the desired air exchange.

3. Importance Of Airflow Calculation

Details: Proper airflow calculation is essential for maintaining indoor air quality, controlling humidity, removing contaminants, and ensuring occupant comfort and health in residential, commercial, and industrial spaces.

4. Using The Calculator

Tips: Enter room volume in cubic feet and desired air changes per hour. Both values must be positive numbers. Common ACH values range from 2-4 for residential spaces to 6-12 for commercial applications.

5. Frequently Asked Questions (FAQ)

Q1: What are typical ACH values for different rooms?
A: Living rooms: 2-4 ACH, kitchens: 6-8 ACH, bathrooms: 8-10 ACH, laboratories: 10-15 ACH, hospitals: 12-25 ACH depending on the area.

Q2: How do I calculate room volume?
A: Multiply room length × width × height in feet. For irregular rooms, divide into regular shapes and sum the volumes.

Q3: Why divide by 60 in the formula?
A: ACH is per hour, while CFM is per minute. Dividing by 60 converts hourly rate to minute rate.

Q4: What factors affect required ACH?
A: Room usage, occupancy, contaminant sources, local building codes, and specific ventilation standards for the space type.

Q5: Can this calculator be used for HVAC system sizing?
A: Yes, this provides the basic ventilation requirement, but professional HVAC design should consider additional factors like heat load, duct losses, and system efficiency.