The fouling factor is important for the selection of an evaporator. The value Onda suggest to input in selection software are:

For evaporators:
-    Normal water in closed circuit: 0,000043 m2K/W;
-    Water in open circuit: 0,000086 m2K/W;
-    Solutions with glycol <40%: 0,000086 m2K/W;
-    Solutions with glycol >40%: 0,000172 m2K/W.

For condensers:
-    Normal city water: 0,000043 m2K/W;
-    Treated tower water: 0,000043 m2K/W;
-    River water: 0,000086 m2K/W;
-    Solutions with glycol <40%: 0,000086 m2K/W;
-    Solutions with glycol >40%: 0,000172 m2K/W.