COMMERCIAL, AND RESIDENTIAL PROJECTS
All J&A projects can be subdivided into two major categories:
noise and vibration problem solving, and
of preventive noise and vibration control treatments and solutions.
resolving existing problems, J&A has at its disposal the proper
instrumentation to fully diagnose the problem and give suggestions
and recommendations for mitigation treatments. J&A will compare
the existing noise and/or vibration levels with the levels allowed
by appropriate noise/vibration standards and regulations (if applicable),
and design treatments enabling compliance with the set noise and
the new projects, in order to prevent noise and vibration problems
from the outset, J&A will work in close contact with the manufacturer,
owner, or builder providing necessary input at the early stages
of this project, and supervising the implementation of the treatments
throughout the construction.
requested J&A will help establishing realistic noise targets
to be achieved for a project. J&A will act as an expert witness
on noise and vibration issues.
are several types of calls that come to J&A concerning noise
and vibration control.
is the manufacturer who needs to make his product quieter in order
to comply with international noise/vibration standards, and successfully
compete on increasingly demanding world and local markets.
is the industrial enterprise seeking compliance with the OSHA's
or other regulations setting requirements for the workspace; or
seeking to lessen noise impact of their operation activities on
the residential neighborhood.
is the client who wishes to control noise and vibration within
his personal living space.
is the organization that would like to optimize acoustical characteristics
within their building, be it a school (with the new stringent
requirements for the core and ancillary learning spaces), a business's
auditorium or a doctor's office spaces.
is the client who wishes to shelter his or her home from the noise
of a busy street, or the neighbor's noisy air conditioning unit.
are neighbors who register complaints when objectionable noise
and vibration encroach from an outside source (be it voices and
music from the neighboring apartment, or footfall noise from the
room above; or some construction work being done in the neighborhood).
is a municipality that needs a traffic noise impact survey, and
the solution to mitigate traffic noise impact on the community;
or that requires a predictive noise study, if a truck stop or
an enterprises is planned to be built in the area.
acoustical disputes arise, there are two major actions that J&A
will commonly take to develop recommendations informing the client
of his options.
First, acoustical measurements are taken of the existing noise and
vibration problem. Questions to be asked are:
equipment is being used and what is its location relative to living
there some parts of the equipment that are a greater source of
noise and vibration than others? For example, in an air conditioning
system there are fans and compressors. The problem may be emanating
from either or both parts of the machinery.
the brand of machinery and contacting the manufacturer for history,
model standards, and steps the manufacturer may have taken to
solve the problem are areas to be investigated.
are the decibel levels at the site and at points radiating from
specific products already exist or can be tailor-made to mitigate
it is important to research the state and local regulations for
standards relating to noise control between properties. The question
has to be asked, "Is there a legitimate basis for complaint?"
there are legal grounds for action or not, J&A can recommend
products and procedures that will quiet the offending source of
the aggravation in the most cost effective manner possible. When
possible we try giving several levels of noise and vibration control
solutions for the client to select the treatments he sees as most
satisfactory within the existing budget.
of Past Projects
Environmental Monitoring - Lewiston, ME
In late 2011 J&A Enterprises completed an environmental monitoring project for the in-water noise during a marine construction project. The US Army Corps of Engineers required that specified in-water noise levels (SEL, and Peak Levels) should not be exceeded during marine pile driving operations. The in -water noise limits were mandated for the protection of endangered marine species inhabiting the waters at the job site. J&A engineer Aaron Korby deployed to the construction site during pile driving operations to monitor the underwater sound levels in accordance with the US Army Corps requirements.
Korby observed that piles installed with a vibratory pile driver were all safely within the environmental noise limits required by the Corps. However piles installed by impact driving were approaching the allowable noise levels. It was suggested that the construction contractor should employ underwater noise mitigation by using an unrestricted bubble screen from compressed air. This technique reduced the in water sound levels to within the specified limits. In deeper water where the noise situation was more severe, the compressed air hose was changed to a more effective configuration having more perforations of a smaller diameter. The effects of water depth and tidal current were noted over the course of the pile installation. J&A provided the contractor with a complete technical report to document the measured in-water sound levels of all the piles in order to demonstrate compliance with the permit requirements. Report contains comparison of in-water noise spectra during pile driving with vibro-hammer and with drop-hammer; and with and without noise mitigating treatments, showing the effectiveness of these treatments.
J&A has the capability to provide similar in-water noise monitoring services for other marine construction projects throughout the US and in other regions. Depending on the sensitivity of the habitat and the environmental conditions, such monitoring services might be required by authorities for variety of construction projects such as offshore wind-farms, marine terminals, waterfront projects, pipeline installation, bridges, or transmission tower installation. Please contact J&A Enterprises at 978-741-1551 to discuss the requirements of your project.
Machinery Noise and Vibration Evaluation - Smithfield, RI
Many products and machines sold in the European Union (EU) are required to meet stringent noise and vibration standards as determined by the European Community (CE). A globally recognized, EU notifying body, TUV, approves results of acoustic testing in order to demonstrate that machinery meets requirements. J&A has gained approval for its professional testing capabilities and certified instrumentation by TUV to conduct Annex VI sound power testing on certain construction machinery for the CE Certification.
Residential Complex - Newton, MA
J&A was hired to address several noise problems in the newly built residential complex in Newton. Several Carrier air conditioning units caused complaints of the residents of the complex and their neighbors. The noise exceeded State of Massachusetts and City of Newton noise regulations. J&A designed full gazebo-type enclosures with the air intake and discharge silencers, which dramatically reduced the noise to the levels allowed by the noise ordinances. The solution took into account stringent Carrier requirements for the allowed increase of the backpressure for the a/c units fans.
Food Plant - Lowell, MA
The plants rooftop incinerator generated high levels of noise
in the neighborhood. J&A has determined that elevated noise
levels were largely due to the incinerator blower. The uncharacteristically
high aerodynamic noise was indicative of the blower unbalance. Balancing
of the blower reduced noise dramatically and eliminated the need
for the construction of intended noise barrier.
pre-production unit of a small compressor intended for hospital
environment was submitted to J&A for noise treatment design.
J&A proposed extensive restructuring of the unit architecture,
selected low-noise cooling fan, determined its optimal position
inside the casing by monitoring temperature of the bearing, head
and motor casing. Proper ventilation, alongside with noise and vibration
isolation and damping treatments enabled J&A to reduce noise
by 18 dB(A). J&As affiliate company Soundown Corporation
supplies precut insulation as designed by J&A for the production
series of the unit.
Based Very Quiet Generator Set:
supplied three 15kW generators for mounting on trucks used in an
acoustic surveillance program. The generators had to have very low
noise emissions even at low frequencies. J&A selected a commercial
generator, and made substantial modifications to the exhaust, intake,
ventilation, enclosure and mounting in order to achieve the specification.
J&A was hired to design treatments for complying with OSHA noise
regulations at the workstations of one of the Bayers plants. Our noise measurements showed that the main
noise excesses were due to the operation of the vacuum pumps. Complete
enclosures for the two types of pumps were designed. The enclosures
incorporated silenced air intake and air discharge for the normal
aspiration of the enclosed pumps, as well as the additional fans
selected prevent the pumps from overheating.
College Residential House - Cambridge, MA
A two family house in Cambridge, MA housing professors had poor noise isolations, which was causing friction between
the neighbors. J&A has developed noise insulation treatment
and has supervised its installation. Both neighbors were quite pleased
with the results of improvements.
Truck Stop - City of Portsmouth, NH
Under the contract with the City of Portsmouth, J&A conducted
an extensive noise survey (including 24-hour noise measurements
and monitoring of activities) of a diesel Truck Stop on US Route
#1 in Portsmouth, NH. Working with the Citys Planning Department,
J&A conducted a preliminary noise impact study: met with the
residents adjacent to the site, developed and distributed a questionnaire
among the residents to assess the perceived severity of the noise
problem. Noise of various noise sources was measured and studied
(refrigeration truck units, idling engines, pneumatic tools used
for tire change, truck air brake release, noise of truck horns,
etc.). The report containing the results of the findings, comparison
to the Citys Zoning Ordinance, EPA and Federal Highway Administration
guidelines and regulations, as well as the design of the noise mitigating
treatments, was submitted to the City (each recommendation was accompanied
with predicted noise levels, and approximate cost of the treatment).
The findings of the survey were presented to the City Council, Planning
and Public Works Departments at an open meeting with residents present.
Written response to the residents questions was submitted
to the Planning Department as a follow-up of the meeting.
A church in Swampscott, MA has installed chimes marking each quarter
of the hour. A big residential area was affected by the sound considered
by some residents as intrusive. J&A was invited to resolve the
dispute. J&A has developed a system of screens redirecting the
chime sound away from the residential area. The church has also
agreed to the J&A proposal to modify the chimes marking only
one-hour intervals. The church clergy and the residents considered
both these measures a reasonable compromise.
Mobile Carrier Manufacturer - Auburn, MA
On several occasions J&A was hired to design noise
control treatments for the new generation of mobile carriers equipped
with generators, fans and other noisy equipment. J&A specified
exhaust silencers to be used with a particular type of equipment
and designed air intake attenuators and soundproof enclosures to
keep the noise inside the vehicles and outside noise pollution within
the required limits.
Generator Noise Pollution - Hartford, CT
A neighbor complained of the noise of the emergency generator installed
in a building of an insurance company in Hartford, CT. J&A was
hired to document noise emission at the property line and design
measures to reduce noise pollution. Noise barriers and air intake
silencers designed by J&A have provided significant noise reduction
and stopped the neighbors complaints.