Data Hall Cooling CFM Calculator
Cooling airflow for a data hall from rack load.
Enter your values
Enter the total it load in kW.
Enter the supply-to-return delta t in F.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Required supply airflow
- 39,491 CFM
- Heat load
- 853,000 BTU/hr
- CFM per kW
- 157.96
- Tons of cooling
- 71.1
- CRAC units at 20,000 CFM
- 2
Quick answer
Data hall cooling airflow is about 3.1 CFM per kW of IT load for every 10F of allowable temperature rise (dT).
CFM = (kW x 3412) / (1.08 x dT)
At a glance
| What it does | Cooling airflow for a data hall from rack load. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Total IT load, Supply-to-return delta T |
| Main output | Required supply airflow |
| Formula | CFM = (kW x 3412) / (1.08 x dT) |
| Cost | Free — no sign-up, no download |
How to use the Data Hall Cooling CFM Calculator
- 1Total the IT load of all racks in kW.
- 2Pick a supply-to-return delta-T, typically 15-25F.
- 3Divide the resulting BTU/hr by 1.08 x dT to get CFM.
Inputs explained
- Total IT load(kW)
- Enter the total it load in kW.
- Supply-to-return delta T(F)
- Enter the supply-to-return delta t in F.
Worked example
Using the values the calculator loads with:
Inputs
- Total IT load250 kW
- Supply-to-return delta T20 F
Results
- Required supply airflow39,491 CFM
- Heat load853,000 BTU/hr
- CFM per kW157.96
- Tons of cooling71.1
- CRAC units at 20,000 CFM2
Frequently asked questions
Why does delta-T matter so much?
Doubling the allowable delta-T halves the airflow needed for the same heat load, cutting fan energy.
Does this include redundancy?
No — add N+1 or 2N margin separately based on your resiliency tier.
What do I need to enter into the Data Hall Cooling CFM Calculator?
Just 2 values: total it load, supply-to-return delta t. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Data Hall Cooling CFM Calculator work out the answer?
Data hall cooling airflow is about 3.1 CFM per kW of IT load for every 10F of allowable temperature rise (dT). It applies the formula CFM = (kW x 3412) / (1.08 x dT) and shows the working so you can check each step by hand.
Is the Data Hall Cooling CFM Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.