What is the difference between spot coolers, portable air conditioners (“portables”) and mini-split or ductless air conditioners?

Air-cooled spot cooling units, spot coolers and portable air conditioners are the same.  These units appeared on the market in the early 1980’s to provide cooling for factory workers, hospitals, data rooms, high rise buildings and anywhere extra cooling is needed.  Portables are practical, self-contained units on wheels for cooling a spot, room or area where IT equipment, people or other assets need cooling or humidity removal.  Portables are available in many capacities and voltages from about 1 Ton to about 10 Tons.  If it is impossible or impracticable to exhaust the hot air created by the a/c unit to the outdoors, portables typically include a duct kit for directing the warm air into the ceiling space in a commercial building.  These units are unsuitable for residential applications.

If larger units are needed for the job, exterior units are required because doors create capacity limitations.

A “mini split air conditioner” is a ductless split unit.  The evaporator section (indoor unit) and condenser (outdoor unit) are separated, or split.   The indoor section mounts on the wall and cools just one area.   Ductless units are permanently mounted and lack portability.

What is the difference between a residential and commercial portable air conditioner ?

These units are unsuitable and will not work for commercial buildings.  A residential portable air conditioner has plastic housing, small condensate tanks, or they evaporate the condensation on the unit’s hot coils, exhausting it into the warm air discharge duct.  A window to exhaust the warm air created by the air conditioner is required to create actual air conditioning because air conditioners create more hot air than they do cold air.  Because electrical amperage is limited in residences, the residential portable units are typically available in no more than 12,000 BTU’s (1 Ton of cooling capacity).  The commercial wheeled portable air conditioners will have larger condensate tanks than residential units, in addition the commercial units tend to have sturdier sheet metal cabinets or housings.

What is the difference between spot coolers, portable air conditioners (“portables”) and evaporative coolers (swamp coolers)? Unlike air condoners, evaporative coolers contribute moisture to the environment because there is no compressor with circulating cold refrigerant to dehumidify.  Evaporative cooling is used in dry cleaners, restaurant kitchens and shops where high moisture and low operating costs are acceptable.  Air conditioners remove moisture from the environment, dry the air and improve the quality of the environment.

What features should I look for when selecting a spot cooler or portable air conditioner?

Construction – Not all portables air conditioners and spot coolers are built the same.   Sheet metal cabinets are better than plastic cabinets.  All residential units are housed in plastic cabinets and some of the inferior quality commercial units have plastic cabinets.  Superior commercial grade units are made of sheet metal and will last about a decade with continuous use.

Warranties - The major (and most expensive) components of a portable air conditioner unit or spot cooler are the compressor and the fans.  It is important these are covered.  Other components tend to be relatively inexpensive to repair or replace.

Cooling Capacity – 12,000 equals one ton by official weights and standards.  When comparing units, sometimes a sell may claim their unit is, say, one ton capacity.  Make sure to ask what the BTU capacity is for the particular unit you are considering.   A seller may call a 10,000 BTU their “one ton unit” and another may call a 14,000 BTU spot cooler a one ton unit.   That’s a 40% difference in actual cooling capacity in two spot coolers that are both called “one ton”.

Controls – For reliability and simplicity of use, simple mechanical controls are a better option.  Some manufacturers provide a digital thermostat (typically a battery operated residential wall thermostat) mounted to the unit to set the temperature.  While helpful in rare cases, cold air actually falls on the thermostat from the front of the unit and gives an incorrect reading, shutting off the a/c unit when the rest of the room needs cooling.  Some portable units offer wall-mounting the digital thermostat which detects the temperature at the place on the wall where the thermostat is mounted.  In most cases, simpler is better for controlling your portable air conditioner.  A dial-type temperature controller is less complicated, more reliable and does not require new batteries.  If the temperature rises, the dial-type thermostat will call for the unit to engage, activating the air conditioner and will usually last several trouble-free years.