Evaporator Evaporators are essential elements of air conditioning and refrigeration systems. Fouling of the unit's coils causes a large percentage of evaporator breakdowns. A/C and refrigeration systems are integrated systems so a problem with one component can create trouble for another. For instance, fouled evaporator coils can lead to a condition known as liquid floodback which can result in flooded compressor starts, loss of lubrication and subsequent compressor breakdown. © 2007 The Boiler Inspection & Insurance Company of Canada.     All rights reserved.