conditioners are small, direct-fired absorption chillers.
An absorption chiller uses a refrigerant, absorbent and heat to create a
cooling effect. Simply put, the cooling effect
is accomplished with the removal of heat through evaporation of a fluid (refrigerant) at
low pressure and the rejection of heat through the condensation of a fluid (refrigerant)
at a higher pressure.
process relies on the affinity between two fluids. Air-cooled
chillers utilize environmentally safe ammonia as the refrigerant and water as the
absorbent. In the chiller unit, heat provided
by a gas burner boils the ammonia out of the water and condenses it in an outdoor coil. The ammonia is then evaporated at low pressure,
cooling a circulating water system. The
chilled water circulates through the area to be cooled via a piping system eliminating the
need for ductwork and making the system well suited to homes with baseboard heating. The ammonia is then reabsorbed into the water (the
absorption process) and the cycle repeats.
here to see a diagram of the residential absorption cooling process.