And cooling units for those enclosures must have regular maintenance. RiNano, a nanocoating from Rittal Corp., Springfield, Ohio, protects condenser coils from water, dirt, and contains neither phosphates nor toxic heavy metals and reduces maintenance.
The 5- µm-thick ceramic coating is transparent, self-cleaning, and resists filiform corrosion and commonly used organic solvents. Chromate and lead-free, it adheres to metals and glass. The company claims field and lab tests confirm the nanocoating does not affect heat transfer to and from the coils or the overall cooling capacity of the air conditioners.
According to Rittal spokesperson Judith Koetzch, testing was done at the Audi brake-disc manufacturing plant in Ingolstadt, Germany. Previously, the plant's cooling units needed filter changes every week, but nanocoated units needed no service during the nine-month test.
Another issue with these cooling units is overflowing condensate collectors. To address the problem, Rittal developed an evaporator that adjusts its thermal output through Positive Temperature Coefficient (PTC) technology. (PTC refers to materials that increase their electrical resistance when their temperatures are raised.)
Rittal's automatic evaporator uses a heating element to evaporate condensate. A standard feature for TopTherm cooling units, the evaporator can get rid of 0.63 gallons/day, eliminating collecting bottles, condensate hoses, and water on the factory floor.