Required sensible airflow (CFM) calculator

Required standard-air flow is calculated as q_sensible / (1.08 × ΔT). Use the stated system boundary and matching input units.

Units

\mathrm{CFM} = \frac{q_{\text{sensible}}}{1.08 \times \Delta T}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

\mathrm{CFM} = \frac{43{,}200}{1.08 \times 20} = 2{,}000

Symbol	Meaning	Unit
$\mathrm{CFM}$	required standard-air flow	cfm
$q_{\text{sensible}}$	sensible cooling load	Btu/h
$\Delta T$	room-supply dry-bulb difference	°F

Symbol	Meaning	Unit
$Q_{\text{air}}$	required standard-air flow	L/s
$q_{\text{sensible}}$	sensible cooling load	kW
$\Delta T$	room-supply dry-bulb difference	K

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.