Which of the following describes evacuation cooling?

Evacuation cooling refers to a method of heat management in which warm air is actively removed from a space, creating a lower pressure environment that helps to draw in cooler air from the surroundings. This process enhances the overall cooling efficiency of systems, particularly in data centers or equipment racks where heat builds up due to high levels of equipment operation.

In the context of the options provided, drawing warm air out to create a vacuum is the essence of evacuation cooling, as it directly helps to manage the thermal environment within the rack or equipment area. By removing the warm air, the system can better regulate its temperature, preventing overheating and ensuring optimal performance of the devices housed within.

Other options do not accurately describe the method of evacuation cooling. For instance, encapsulating heat or heating air within the rack would lead to heat retention rather than its removal. Blowing air down through the rack could be a cooling strategy but does not embody the concept of creating a vacuum effect through air evacuation.