Cooling towers are among the heaviest pieces of equipment that are located on the roof top of buildings. Often their change in operating weight poses a great challenge when isolating cooling towers for vibration and restraining them for wind or any seismic activity. Also noise control is another common problem faced in a cooling tower that is often overlooked. Cooling towers are applications or devices that are installed close to the property line or office windows and the noise coming from the fans of these cooling tower causes a nuisance.
Problem: Air borne noise
Sound levels in the property line are required to be at 45 to 60 DBA, again depending from location to location they vary and noise above this level results in complaints from neighboring offices or residents. Due to the extremely low static capabilities of the cooling tower fans, coupled with moisture and corrosion issues, makes the noise control solution in the vicinity all the more challenging.
What may seem to be a difficult challenge to many, is surely not a challenge for Andre HVAC Inc. with their assistance in acoustic calculation, will help determine whether noise control is required and, if so, which equipment best suits to isolate the noise.
Andre HVAC Inc.’s restrained seismic spring mounts provide control of structurally transmitted noise and vibration, with limited movement. By installing these spring mounts, equipment are restrained in all directions and thus reducing damage caused by conditions that would otherwise move equipment excessively. Restrained Spring Mounts are ideal for protecting connections to Cooling Towers wherein the weight can change with fluid fluctuations that cause the units to move vertically. Also with these restrained seismic spring mounts they also meet most of the building code requirements where earthquakes and high wind load conditions are experienced.
Problem: Structure borne noise
Structure borne noise is noise traveling through the structure instead of the air. Vibration from the fan is transferred to the structure creating high frequency noise problems in different parts of the building. Unlike airborne noise, diagnoses of structure borne noise post design is challenging.
Due to the potential change in the operating weight of the cooling tower, restrained isolators are recommended to be installed in the application. It is recommended that a minimum of 2-inch deflection is required so that the springs in use, operate at a high efficiency. Also, for cooling towers that are not engineered to withstand point loading, a structural base is required for better performance of the application. Andre HVAC Inc. manufactures a number of restrained isolators to meet the application requirement of clients for noise and vibration isolation.