With the application of heat at the generator, ammonia vapor is driven from the solution. This hot vapor rises into the separator and a portion of the water condenses and flows by gravity into the absorber. The hot ammonia vapor continues to rise into the condenser where it gives up its heat to the surrounding air and condenses into a liquid. The liquid ammonia enters by gravity into the evaporator, where it is mixed with hydrogen gas. Circulation of hydrogen gas causes a reduction in pressure within the evaporator.The low pressure causes the ammonia liquid to boil into a gas (evaporating) and absorbing heat in the process (refrigerating effect).The mixture of hydrogen/ammonia vapor that’s carrying the absorbed heat is now drawn by gravity into-the absorber.Because the water from the separator has a greater affinity for ammonia, it separates from the hydrogen gas.The hydrogen gas being very light rises and returns to the generator to start the cycle again.