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💨 CFM Calculator
HVAC Air Flow Volume & Ventilation Calculation Tool
Airflow Calculation Results
Total Room Volume:
0 cu.ft
Required Air Flow (CFM):
0 CFM
Estimated Cooling Capacity:
0 Tons
Understanding CFM in HVAC Systems
CFM stands for Cubic Feet Per Minute, which measures the volume of air moved by an HVAC blower or ventilation fan per minute.
- Formula: Total CFM is calculated using
CFM = (Room Volume × ACH) ÷ 60. Explore more technical modules at JCI Classes Official Portal. - Cooling Load Estimation: Typically, 1 Ton of cooling requires approximately 400 CFM of airflow based on ASHRAE Design Guidelines.
- Air Changes Per Hour (ACH): Refers to how many times the entire air volume of a room is replaced within 60 minutes.
Frequently Asked Questions (FAQ)
Q1. What is the basic formula to calculate CFM for a room?
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To calculate CFM: First find room volume (Length × Width × Height in feet). Multiply Volume by ACH (Air Changes per Hour) and divide by 60 minutes.
Formula: CFM = (Volume × ACH) ÷ 60
Formula: CFM = (Volume × ACH) ÷ 60
Q2. How many CFM is required for 1 Ton of AC capacity?
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As a standard HVAC rule of thumb, 1 Ton of air conditioning capacity requires approximately 400 CFM of conditioned airflow.
Q3. Why is correct CFM calculation critical in HVAC design?
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Incorrect CFM leads to poor cooling/heating distribution, inadequate humidity control, excessive blower fan energy consumption, and noise issues inside air ducts.