The currently used cooling technology is based on the mechanical compressor. The 4 major components of the cooling unit are the compressor, evaporator, condenser and expansion valve. Due to the age of this technology and these components, their manufacturing processes have been optimized as these components have become standard and common. Compressors are used in multiple applications and in cooling alone since the 1800s. In terms of its structure, it is a compact chamber with a rotary blade or component within it. It does not require much material. Similarly the evaporator and condenser too are common heat exchangers and the expansion valve is also an old member of the mechanical engineering field. Because of mass production, optimizations and improvements over time, and the simplicity of the structures involved, the cooling units are cost effective.
Cooling units are categorized as chillers and air conditioners. Chillers are larger capacity and provide cold water whereas air conditioners tend to be smaller in size and provide cold air. Air conditioners tend to be more expensive per ton of cooling than chillers because they are in the smaller scale where the fixed costs tend to be large. They also contain fans for air handling within the unit. A 1 ton air conditioning unit can cost around $1000. However, a 5 air conditioning ton unit will cost around $3,200 reducing the per ton cost to around $640.
Chillers tend to be cheaper since they are much larger in size. There are two types of chillers : air cooled and water cooled. An air cooled chiller costs around $700 per ton below 150 tons and $450 per ton above that capacity. Water cooled chillers are cheaper at around $400 per ton below 400 tons and $300 per ton beyond that. However, water chillers need an extra motor and a cooling tower which usually increases the capital investment to more than that of an air cooled chiller.
The above capital costs of purchasing one of these units can be understood better if we take a look at their operating costs. A manufacturing plant that uses a chiller at its site to cool down a process spends around $700 per ton of cooling annually. This is already more than the cost of a chiller per ton and it arises from the electricity consumption of the chiller. Therefore we can see that the compressor based cooling technology is cost effective to purchase but it is not very cost effective in the long run. The operating costs might not justify the low capital cost. With increasing electricity prices, the operating costs might go beyond what many consumers can afford.