Sensible Heat Airflow Calculator
CFM needed for a sensible heat load.
Enter your values
Enter the sensible load in BTU/h.
Enter the temperature difference 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 airflow
- 1,111 CFM
- In m³/h
- 1,888
- Load in kW
- 7.03
- Airflow per 1000 BTU
- 46.3 CFM
Working
- 124,000 / (1.08 x 20) = 1,111 CFM
Quick answer
The sensible heat equation says BTU/h equals 1.08 times CFM times temperature difference at standard air.
CFM = BTU/h / (1.08 x ΔT)
At a glance
| What it does | CFM needed for a sensible heat load. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | Sensible load, Temperature difference |
| Main output | Required airflow |
| Formula | CFM = BTU/h / (1.08 x ΔT) |
| Cost | Free — no sign-up, no download |
How to use the Sensible Heat Airflow Calculator
- 1Enter the sensible portion of the load in BTU/h.
- 2Choose the temperature rise or drop across the coil, typically 18-22°F.
- 3Size the blower and duct for the resulting CFM.
Inputs explained
- Sensible load(BTU/h)
- Enter the sensible load in BTU/h.
- Temperature difference(°F)
- Enter the temperature difference in °F.
Worked example
Using the values the calculator loads with:
Inputs
- Sensible load24000 BTU/h
- Temperature difference20 °F
Results
- Required airflow1,111 CFM
- In m³/h1,888
- Load in kW7.03
- Airflow per 1000 BTU46.3 CFM
- 24,000 / (1.08 x 20) = 1,111 CFM
Frequently asked questions
Where does 1.08 come from?
It bundles air density, specific heat and 60 minutes per hour at standard conditions.
Metric version?
kW = 1.21 x L/s x ΔT in °C, divided by 1000.
What do I need to enter into the Sensible Heat Airflow Calculator?
Just 2 values: sensible load, temperature difference. 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 Sensible Heat Airflow Calculator work out the answer?
The sensible heat equation says BTU/h equals 1.08 times CFM times temperature difference at standard air. It applies the formula CFM = BTU/h / (1.08 x ΔT) and shows the working so you can check each step by hand.
Is the Sensible Heat Airflow 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.