The gas tightness class (according to DIN V 18160-1) or pressure class (according to DIN EN 1443) indicates the mode of operation for which an exhaust system is designed. It shows the maximum overpressure, measured in pascals, that may prevail in the system and the permissible leak rate. According to DIN V 18160-1, exhaust systems or parts of exhaust systems must be marked accordingly.
The following six classes are distinguished:
Negative pressure classes N1 (-40 Pa) and N2 (-20 Pa):
Labelled product is permitted for negative pressure operation in conventional fireplaces with solid fuels, oil and gas.
Application:
N1: outdoor/building
N2: outdoor/in-building
overpressure classes P1 (200 Pa) and P2 (200 Pa):
Marked product is permissible for positive and negative pressure operation in fireplaces with low-temperature and condensing technology.
Application:
P1: indoors/outdoors
P2: outdoors, with negative pressure also in buildings
High-pressure classes H1 (5000 Pa) and H2 (5000 Pa):
Labelled product is permitted for positive and negative pressure operation in large-sized fireplaces, which are rarely found in house construction, e.g. combined heat and power plant.
Application:
H1: indoors H2:
outdoors, in case of negative pressure also indoors.
Source: bauwion
