BS EN 60704-2-13:2011 pdf free.Household and similar electrical appliances—Testcode for the determinationof airborne acoustical noise Particular requirements for rangehoods.
BS EN 60704-2-13 Air-extraction range hoods shall be loaded using a pipe connected to a muffler according toFigure 101.The pipe shall be rigid with smooth inner walls and shall have the widest diameteramong those specified by the manufacturer. lf not stated, a standard pipe with the best fittingdiameter shall be used.The muffler shall have an insertion loss as specified in the table ofFigure 101. lt shall have a circular section with the same internal diameter as that of the pipe,a length as specified in Figure 101 and shall not have parts protruding inside that may causeadditional pressure drops. The pipe and the muffler shall also comply with all thespecifications reported in Figure 101 and care shall be taken that they do not radiate noise.
Range hoods with external fan shall be connected to the fan with a pipe and a muffleraccording to Figure 103.The pipe shall be rigid with smooth inner walls and shall have thewidest diameter among those specified by the manufacturer. lf not stated, a standard pipewith the best fitting diameter shall be used.The muffler shall be provided with the appliance.lf the manufacturer did not provide a muffler, the appliance is tested without muffler.
In particular，when connecting the pipe and muffler system to the range hood, care shall betaken that this connection does not transfer any additional structure borne noise.For thispurpose,isolating connecting pieces can be used.
Static forces from the standard exhaust to the range hood shall also be avoided.
NOTE 101 The fastening of the muffler should not influence the acoustical field in the test room; for example twowires could be fixed around the muffler and on the ceiling.
Whenever it is possible to choose among two or more exit holes for the pipe connection, theone on the upper side of the range hood, if any,shall be used.
Range hoods designed for connection with more than one pipe at the same time shall beconnected accordingly to the number of pipes required.BS EN 60704-2-13 pdf download.