IEC 60704-2-2 pdf download – Household and similar electrical appliances – Test code for the determination of airborne acoustical noise – Part 2-2: Particular requirements for fan heaters

IEC 60704-2-2 pdf download – Household and similar electrical appliances – Test code for the determination of airborne acoustical noise – Part 2-2: Particular requirements for fan heaters
Windscreens should be used and the relevant corrections for changes in the microphonesensitivity shall be added to the observed sound pressure levels.
6 operation and location of appliances under test
This clause of part 1 is applicable except as follows:
6.1 Equipping and pre-conditioning of appliances6.1.1Addition:
Air filters, if any, shall be clean.
6.1.3Replacement:
Prior to noise measurements，the appliance equipped in accordance with Subclause 6.1.1,shall have been in operation for a total period of at least 2 h for running-in at the highestspeed setting with the maximum heating switched on for normal permanent use.
Oscillating function if available shall be switched on.
During the running-in procedure air filters,if any,may be removed. lf filters remain in theappliances during this running-in period, they shall be clean or renewed after this period.
6.1.4Replacement:
lmmediately before each series of noise measurements，the appliance equipped inaccordance with Subclause 6.1.1 shall be operated for stabilizing at the highest speed settingand maximum heating switched on for normal permanent use for 5 min.
6.2supply of electric energy and of water or gas
6.2.1 Modification:
The voltage tolerance shall be ±0,5 %.
6.2.2 Not applicable
6.2.3Replacement:
The appliance shall be operated with the heating elements switched on.
Special attention is required to be given to the possible effect of the temperature rise on theacoustical behaviour of the test room.
6.2.4 Not applicable
6.4Loading and operating of appliances during tests6.4.2Replacement:
The appliance shall be equipped according to 6.1.1.
The noise emission shall be determined with the appliance at the highest speed setting andmaximum heating for normal permanent use.Oscillating mechanism, if any, shall be switchedon.
NOTE Other possible speed settings ( minimum heat output, boost position…) can be measured in addition. Therespective noise levels should be linked to the relevant heat output.
Appropriate adjustment of air intake or exhaust openings shall be done taking into accountmanufacturer’s instructions if any，or otherwise selecting the configuration that gives thehighest noise emission.
6.4.3 Not applicable
6.5 Location and mounting of appliances6.5.1 Addition:
The tests under the conditions stated in Subclause 6.5.3 shall be repeated for floor standing-appliances which may be placed either against or away from the wall.
For such appliances both sets of results shall be recorded and the measurement that giveshighest noise is then chosen.
6.5.2 Not applicable
6.5.3 Replacement:
For measurements on floor-standing appliances intended for placing against a wall,includingthose for building in，a vertical refiecting plane having an acoustic absorption coefficient ofless than o,o6 must be used.
When measurements are made in a reverberation test room, a part of the wall of the room willserve for this purpose.The minimum area of this part of the wall should be determined by theprojection of the appliance extended by at least 0,5 m upwards and to both sides. Theminimum distance between any surface of the appliance or its cabinet and the nearest cornerof the room shall be 1 m.
When measurements are made in a free-field environment, the size of the vertical reflectingplane (supported by the horizontal reflecting plane) shall be at least equal to the size of theprojection of the measurement surface.
For both types of test environment the following requirements shall be complied with:
– the appliance shall be placed in the test environment without any resilient means of
support other than those incorporated in the appliance;
care should be taken to avoid any direct contact between the appliance (includingprotruding parts, worktops,spacers, etc.) and the vertical reflecting wall;
the distance between the wall and the appliance shall be established by placing theappliance in direct contact with the wall and moving it away for a distance not exceeding10 cm ±1 cm.