The sources of noise are numerous, and in some cases are entirely dependent upon the location and the type of building structure.
Common sources of noise are as follows:
1. Line rattles, that is pipework or control tubing vibrating against an evaporator or condenser shroud or framework.
2. Items of stored products (metal containers) or storage shelves vibrating.
3. Evaporator or condenser fan mountings loose.
4. Condensing unit base mountings or mounting frame loose; inadequate noise suppression from mounting fabric used (Tico pads, for example).
5. Perished rubber mounting grommets, which are especially prone to deterioration if contaminated with oil and refrigerant.
6. Gas pulsations against a rigid pipework design, creating a noise source during operation or when the compressor starts and stops.
7. Incorrect belt tension or belt and drive pulley alignment with open-type condensing units.
