Chapter 62 pdf heating and air conditioning components and operation article is about cooling of air. Air conditioning units outside a building.
Air conditioning can be used in both domestic and commercial environments. Electric refrigerant-based AC units range from small units that can cool a small bedroom, which can be carried by a single adult, to massive units installed on the roof of office towers that can cool an entire building. In common usage, though, “air conditioning” refers to systems which cool air. Since prehistoric times, snow and ice were used for cooling. This practice was replaced by mechanical ice-making machines.