Estimates only. These results may be wrong for your specific installation, and they are not engineering or code-compliance advice. Check every result against the code that applies to you and with your local inspector (AHJ) before you install anything. Terms of Service
Estimate the heat inside an enclosure and the fan airflow needed to hold it at your maximum internal temperature. Results update as you type.
Enclosure
Heat sources
Heat
How the enclosure cooling calculator works
Describe the enclosure, its surroundings and the parts that make heat and the calculator adds it up, subtracts what the enclosure walls shed on their own, and shows the airflow a fan needs to move to hold your maximum internal temperature.
Steps
- Enter the maximum ambient temperature and the maximum internal temperature you want, in °F.
- Choose wall mount or free standing, and indoor, outdoor shaded or outdoor in the sun.
- Enter height, width and depth in inches.
- Add heat sources: a VFD by horsepower or by amps, a line reactor, or any part by its watts.
- Read heat to remove in watts and the required airflow in CFM. The formulas are listed under How this is worked out.
Example
If 1,000 W of heat must be removed and the inside may be 15°F hotter than the surrounding air, the airflow formula gives 3.16 × 1,000 ÷ 15 ≈ 211 CFM.
Questions
- Does it size an air conditioner?
- It reports the heat to remove in watts. Use that number with a cooling unit's own rating table. Filters, dust and altitude reduce a fan's real airflow, so leave margin.
- What if the answer says the enclosure sheds heat on its own?
- When the walls can shed all the heat at your temperature limits, the heat to remove is zero or negative and no fan is needed on paper. Real enclosures still deserve margin.
- Where do the loss numbers come from?
- They are rules of thumb shown on the page, such as about 3% loss for a VFD and a per-square-foot wall dissipation figure. Replace them with manufacturer data when you have it.