Spot coolers work similar to air conditioners. An air conditioner can’t just create cooling from nothing; it can only relocate heat. There's no magic to air conditioning yet!
The Air Conditioning Process
In the air conditioning process, the heat is removed in two ways; an actual drop in temperature and as water. The air passes over a closed-loop coil filled with refrigerant and the air is cooled and dehumidified. The cold air is delivered to the space being cooled and the condensate -- the water produced by dehumidification -- is pumped or drained away.
The Spot Cooler Difference
A true self-contained spot cooler does just that -- cools a spot, or an area. The evaporator supply air -- the cold air -- is usually directed to an area through a directional louver or a nozzle. With a self-contained spot cooler, the evaporator -- the cold air side -- and the condenser -- the warm air side -- are both contained in the same cabinet like the unit in the diagram.
Think about your air conditioner at home. There are two seperate systems. The evaporator section is INSIDE the house and the condenser section is OUTSIDE the house. These two sections are connected with refrigerant lines.
Since a standard air conditioner has the condenser located outside, the air needed for the condenser coil -- the condenser air intake -- is drawn in from an area outside the area you are cooling.
A Spot Cooler CAN BE an Air Conditioner
Most spot coolers usually operate as spot coolers -- they use the air in the space they are cooling for make up air which is the air for the condenser intake. In order for a spot cooler to be a true air conditioner, the condenser air must come from outside the space you are cooling so you aren't "stealing" the air from the space.
A make up air duct kit can be used with a spot cooler to turn the unit into an air conditioner. With this kit, the air for the condenser is brought in from another area; typically, the ceiling above the room you are cooling or from an adjacent room.
Using a make up air duct kit allows all the cold air to stay in the room and none of it is used to cool the condenser since the intake air is ducted to the condenser from another area.
Should You Use a Spot Cooler or Portable Air Conditioner
Spot coolers are versatile and used in so many applications. But remember, you will always get more effective and efficient cooling if you use a portable spot cooler as a portable air conditioner. So if you can, go ahead and install that make up air duct so you have a true air conditioner. If you already have a spot cooler and your room isn't getting quite cool enough, you can probably even purchase the extra accessory items needed to turn it into a portable air conditioner. You'll be surprised how much cooler your room will be.