Cooling towers are used to cool condenser water from chillers in large buildings. The towers are usually perched on roofs on isolators. When these towers are placed on closely huddled buildings, the noise from the tower on one building might be a nuisance to the occupant in the next. In fact, the noise can be high enough for the building owner to be in contravention of the Municipal Noise By-Law regulations. This means that building owners can be fined, sued or both if the noise problems are not resolved. Vibro-Acoustics is often called upon to resolve noise mitigation issues on war like footings.
Fan noise from the condenser and air intakes can be loud enough to cause noise issues.
Vibro-Acoustics can design silencers to be installed on cooling tower air intakes and discharge. We also design barriers to break the line of sight between the cooling tower and the receiver.
Low Static Pressure on the Fans
Propeller fans are most commonly used in induced draft cooling towers. These fans have very low static available to them. Catalogue selections may not take the system effects into consideration thereby increasing the pressure drop beyond what is indicated by the manufacturer on their submittal. This may cause the cooling tower to perform improperly due to lack of air flow through it.
Vibro-acoustics silencers are selected with system effects in mind. The submittal will show pressure drop with system effects so that the designer knows how much pressure drop to expect once the silencers are installed.
Tower and Fan Maintenance
Installing silencers on the intake and discharge seems to solve the problem. But then there are maintenance access issues. It is not feasible to have a crane on top of a building every time the tower needs to be serviced
Vibro-Acoustics noise control solutions take into account the maintenance considerations. Access doors and sections can be incorporated into the design so that the service personnel can have access to the equipment when required.
Seismic and Wind Considerations
With silencers and barriers installed on cooling towers perched up on the roof, seismic and wind considerations come into play. The added surface area can cause the silencers and enclosures to blow away, especially with territories susceptible to high winds, hurricanes and tornadoes
Vibro-Acoustics can design structural elements to go with silencers and barriers. These structural members are designed around the wind loads expected in that territory. Anchorage calculations can also be provided for the silencer and barrier solutions.