How many approaches are there to remove unwanted heat from an IT environment?

There are five common approaches to removing unwanted heat from an IT environment:

Air conditioning: using mechanical cooling to remove heat from the air.

Air economization: using outside air to cool the IT environment when the temperature is cooler than the desired temperature inside the data center.

Liquid cooling: using a liquid coolant to absorb and remove heat from IT equipment.

Evaporative cooling: using water evaporation to cool the air.

Immersion cooling: submerging IT equipment in a liquid coolant to remove heat.