The main difference between adsorption chillers and absorption chillers is during the adsorption method the water is adsorbed onto a solid (the non-hazardous or corrosive silica gel) and in the absorption method the water is dissolved into a liquid (the corrosive lithium bromide).

Absorption chiller makes chilled water through the 4 cycles of ¡°evaporation,¡± ¡°absorption,¡± ¡°generation,¡± and ¡°condensation.¡± This is eco-friendly air conditioning system that uses water as refrigerant, without using Freon Gas (CFC, HCFC) which might be a cause of Global Warming or Ozone Depletion.

Adsorption chillers are considered to be one such technology; however, their main disadvantages include a low cooling capacity, a low energy efficiency ratio (EER), and cyclic operation. Thus, a great deal of effort is being put into improving adsorption-chiller performance.

In contrast, an adsorption chiller—which is made up of an evaporator, two adsorption chambers, and a condenser—warms the gas back to a liquid without using any moving parts. Both adsorption chambers are filled with silica gel (the adsorbent is often lithium bromide), and water is the refrigerant.