Technical Booklet L Combustion Appliances and Fuel Storage Systems·Page 90·B.9
Condensate resistance classes
Condensate resistance classes are designated as 'W' for wet operations (able to contain condensates) or 'D' for dry operations (with high flue gas temperatures to avoid condensate formation). The 'W' class is aimed at condensing appliances.
Condensate resistance class – expressed as either 'W' for wet or 'D' for dry operations. A product designated 'W', able to contain condensates within the flue, is aimed at condensing appliances. A product designated 'D' would usually have flue gas temperatures high enough to avoid condensate formation.
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