SWUD: More than just an acronym
Back in the 1990's, the Trane Company, now part of Ingersoll-Rand, introduced a line of Environmental Unit's designed to condition low & mid-rise buildings. These units model numbers began with four letters ... You guessed it , SWUDU9042**BC360095BB101, as you can see if you do not have a Trane operations & maintenance book handy, the short cut to defining what this unit is would be simply to call it a SWUD unit. These systems have gained in their sophistication and the markets served and now are commonly used in high-rise building applications.
The design of these systems are very compact and deliver a great punch for the limited foot-print that they consume in regards to floor space. SWUD-style units have a complete mechanical system built within them to allow for the total conditioning of an office environment with the exception of the heat rejection component. Either a cooling tower or a remote condenser.
Just like in any home or office, laboratory or data center air conditioner, there a four required components to provide "cooling". The Compressor(s), Condenser, refrigerant Metering Device, commonly refereed to as a TXV or a TEV and lastly the Evaporator, this is the section where the heat from the air stream jumps into the refrigerant in order to produce the cooling effect that we all need this time of year.
The basics of refrigeration are not all that basic, if you would like, please let me know via @gregcrumpton on Twitter and I will dive deeper into the particulars on the vapor compression cycle (refrigeration) itself.
The gist of this note is to allow you to understand that a SWUD unit, usually resides in the mechanical room of your building, is connected to a medium pressure duct (air distribution) system, works in conjunction with the buildings temperature controls and 9 times out of 10 is connected to a common cooling tower that serves as the final point of heat rejection from the building into the atmosphere.
This is a real simple explanation, but knowing the acronym may allow you to know whom to call if indeed you are hot and sticky at work.