Do we have to put up with vibration from plant equipment? Acoustics guidance for building designers and plant room managers
Whether we’re in a residential or an industrial setting, we’ve all encountered situations where we’re forced to put up with noise disturbance from a pump, pipe or fan, but should we have to? Adam Fox, our director at vibration control specialist Mason UK, explains why simply following the available guidance should eliminate this all-too-common problem.
Many modern structures, whether industrial or residential, require water pumps, ventilation, air conditioning, and heat pumps (HVAC). Mechanical elements in all of these forms of industrial equipment, however, cause vibration. This vibration can be transported throughout the building via ducts, piping, or structural elements, and manifested as audible noise.
Historically, much of this equipment has been stored in the building’s basement. With space at a premium these days, that could mean living next to a noisy plant room. Alternatively, this equipment could be placed on the building’s roof, where it would be out of the way.
That might be a great option from an architectural point of view, but it can accentuate the issue of noise pollution. The structure of a building must become more lightweight as it rises in height. This allows vibrations generated by the equipment to be carried directly through the structure or via service runs, where they can manifest as noise. This noise can be a health issue as well as a planning issue. You don’t have to put up with it, though.
Where to start with vibration control for plant machinery?
Ideally, building acoustics should be considered at the design stage. It is often much simpler and more cost effective to address issues at this stage, as opposed to costlier retrofits further along in the life of the building, after complaints start to occur. Unfortunately, acoustics is sometimes considered something of a dark art and vibration control is even more of an esoteric area, so where do you start?
The Chartered Institute of Building Services (CIBSE) provides clear guidance on this. The CIBSE B4 guidance document, first developed by experts in the 1960s and most recently updated in 2016, provides guidance on the generation, prediction, assessment, and control of noise and vibration from building services.
Regrettably, the existence of these guidelines, as well as their potential utility, is largely unknown. The document outlines some of the most common issues that arise from HVAC systems, with a section dedicated to plant rooms. Enforcing these guidelines from the start would quickly eliminate the majority of the common issues that arise in new construction.
When things go wrong with plant vibration
Were you face a noise or vibration problem in a pre-existing building, the B4 document should still be your first port of call. Despite the availability of this guidance, there are many common problems that result simply from ignorance of the guidelines.
In general, the two most common vibration issues are an incorrect isolator selection or a poorly designed product. In situations where springs or higher deflection elastomeric supports are required, placing plant equipment on cheap, overly stiff mats or pads is a common mistake that applies to both categories. The springs could be several hundred pounds, while the matts could be a few pounds.
However, we are frequently involved in retrofit projects where cheap pads must be replaced with spring mounts. When you factor in the time and cost of consulting fees, as well as the disruption and ire of tenants, any savings are quickly erased. Furthermore, there is a responsibility to consider a building’s total life cost, as remedial work incurs a carbon cost.
Many of the most common issues are easily resolved, but non-experts accept them because they believe they have no choice, and contractors install sub-optimal systems due to a lack of oversight or experience. We once worked with a large automotive manufacturer whose plant equipment, specifically a climate chamber with a vacuum pump, was causing vibration in an office 400 yards away. They had called in multiple companies over a period of years to try to solve the problem before finally finding us. The final solution was actually quite simple.
We may have to put up with noise from plant equipment, but it shouldn’t be that way. Noise disturbance would be the exception rather than the rule if the industry standards outlined in the CIBSE B4 guidance were properly implemented. Don’t be afraid to ask for more; after all, you deserve your peace and quiet!