1. What is a Ventilation Rate Calculator?

Definition: This calculator determines the required ventilation rate in cubic feet per minute (cfm) based on air changes per hour and room volume.

Purpose: It helps HVAC professionals, engineers, and building designers ensure proper air circulation in enclosed spaces.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Ventilation Rate — Air flow in cubic feet per minute (cfm)
• ACH — Air changes per hour
• Volume — Room volume in cubic feet (ft³)

Explanation: The formula converts air changes per hour to the continuous airflow rate needed per minute.

3. Importance of Ventilation Rate Calculation

Details: Proper ventilation maintains indoor air quality, controls humidity, removes contaminants, and ensures occupant comfort and health.

4. Using the Calculator

Tips: Enter the required air changes per hour (ACH) and room volume in cubic feet. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical ACH value?
A: Residential spaces typically need 4-6 ACH, while commercial buildings may require 6-10 ACH or more depending on use.

Q2: How do I measure room volume?
A: Multiply room length × width × height in feet to get cubic feet.

Q3: When would I need higher ACH values?
A: Spaces with pollutants (like kitchens, labs) or high occupancy may need 10-15 ACH or more.

Q4: Does this account for infiltration?
A: No, this calculates mechanical ventilation needs. Natural air leakage may provide additional air changes.

Q5: How do I convert cfm to other units?
A: 1 cfm ≈ 1.7 m³/h or 0.0004719 m³/s.