Below are formulas to help calculate heat load and select arack air conditioner:
1. Add up the wattage of each device and convert it to BTU (a device’s manual usually lists its wattage). You can also determine wattage with the following formula (Watts=Volts X Amps).(5) Remember that 1,000 Watts=1kW.

2. If a rack air conditioner will be used, for every 1 kW consumed, consider that 3412.14 BTU is generated. Air conditioners are rated for different BTU levels.

Additional Tips
Other ways to improve cooling include using blanking panels to manage air flow efficiency, selecting a rack with built-in channels for better cable management and improved air flow, and removing any obsolete or unnecessary equipment from the rack. In addition, consider that 3-phase power can significantly increase available amperage into the server rack, reducing the
overall number of PDUs needed to power equipment and leaving more space for airflow.