CFM Calculator for 100 Sq Ft Room
Find the exact CFM airflow needed for a 100 square foot room. Get recommended duct sizes, BTU load estimates, and HVAC sizing data for 100 sqft spaces.
Airflow Requirements for 100 Square Feet
Required CFM
100
Est. BTU Load
2,500
Cooling Tons
0.21
Duct Size
6"
A 100 square foot room requires approximately 100 CFM of airflow for proper heating and cooling. This is based on the industry standard rule of 1 CFM per square foot. The estimated cooling load is 2,500 BTU (0.21 tons), and the recommended round duct size is 6 inches at a quiet velocity of 700 FPM.
How We Calculated This
Step 1: CFM Requirement
CFM = 100 sqft × 1 CFM/sqft = 100 CFM Step 2: BTU Load Estimate
BTU = 100 sqft × 25 BTU/sqft = 2,500 BTU Using 25 BTU per square foot as a general residential estimate. Actual load depends on insulation, climate, and sun exposure.
Step 3: Duct Size
Diameter = √(4 × 100 ÷ (π × 700)) × 12 ≈ 6 inches Based on 700 FPM velocity for quiet residential operation.