Within the framework of the revision of Regulations 1253/2014 and 1254/2014, stricter requirements for leakage from residential ventilation units are planned (limit value for placing on the market; consideration in the calculation model for the energy label).
The test standard on this subject, EN 13141-7, describes three test methods for internal leakage. For appliances with plate heat exchangers (PHE), the static method is typically used. For rotors, the standard requires one of the two dynamic methods to be applied. There are no known tests in which all three test procedures were carried out on the same unit. Furthermore, no comparisons have been made between units with PHE and rotors with the same test procedure. Experts agree that the results of the three procedures are not comparable according to the current state of knowledge. Thus, different declared characteristic values of heat recovery can result, depending on the test method selected. The current situation is unsatisfactory for manufacturers, customers and authorities. The Product Group Residiential Air Handling Units (PG-RAHU for short) of the Eurovent trade association has therefore taken the initiative to clarify the situation and, if possible and sensible, to initiate a uniform test procedure. The Lucerne School of Engineering and Architecture conducts the experimental investigations, prepares the calculation models and develops proposals for a standardization of the test procedures.