CF-Cozby Library-CS000420Please deliverth e following pages to:
Company'
Fax#: ~-3o~(- 3~w s Date:
From: Kirby Jordan ext. 106
Total number of pages (including cover sheet)'
If you do not receive all of the pages,
P/ease contact us as soon as possible.
Phone # (800) 779-4274
Fax # (214) 920-2529
Comments' ~-"¢xc:/~s4zJ '~ -{-~ rofer~ u-/(~ O(~'~¢~.S'--%¢(../.
100 F. San -\nten~o ~
NuTL¢ 20 I
Sail Ntaro~s. '['N 786,06
512..'1'Y2 .il I.~
51~.392.3123 ti'3,
w ww.join~'technologv.eom
March 27, 2000
Mr. Kirby Jordan
t~ 184 Park Valley Drive
Coppell, TX 75019
oIN-ER
T E C H N O/L O G Y Re: Noise Control
~,, G R O U P City of Coppell
William T. Cozby Public Library
Dear Kirby:
it was a pleasure to meet with you and Leonard concerning the noise being generated
by the library air-cooled chiller and the impact of this noise on surrounding properties
some 90 feet distant.
Overview:
During our visit of March 23, 2000, we made a series of acoustical measurements to
determine the magnitude, source and paths of noise disturbances reaching your
property line from the operation of the aforementioned air conditioning equipment.
The purpose of the noise measurements was to determine the violation, if any, of the
noise levels promulgated as being acceptable environmental noise levels by
governmental agencies.
The criteria for maximum environmental noise levels, (excluding transportation
noise), at a residential property line at an elevation of 5'-0" above mean ground level
are as follows:
* Day Time Hours - 56 dBA
· Night Time Hours - 49 dBA
Some authorities specify length of;Jay from sun up to sunset, or from 7:00 AM to
7:00 PM, or fxom 7:00 AM to 10:00 PM.
a. The city of Dallas specifies day time hours as 7:00 AM to 7:00 PM,
b. HUD/FHA specifies day time as being from 7:00 AM to 10:00 PM with
a I0 dB penalty imposed after 10:00 PM,
c. FAA, EPA, the Quiet Communities Act and others use 55 dBA for
daytime and 45 dBA for nighttime hours.
For this report we recommend the 55 dBA level for the period 7:00 AM to 7:00 PM
and 45 dBA for the period from 7:00 PM to 7:00 AM.
Innovative Multimedia Environments
Joiner Technology Group
At about 3:30 PM on March 23, 2000 we measured 61 dBA at your property line.
Due to thc presence of reflective surfaces this could increase to as much as 68 dBA
under certain weather conditions. We suggest that the threshold for remediation be
set at 68 dBA. This would result in a noise level that is 23 dBA above the nighttime
criteria of 45 dBA.
We noted and measured the following four (4), noise sources: 1. Air Conditioning Compressor Units,
2. Fan Discharge,
3. Fan Intakes,
4. Air Intake to AHU-1.
As this is an air-cooled system, each of the above elements requires air movement for
operation and ventilation. Items numbered 1, 2, & 3 are engineered for very little
additional air pressure drop without dropping below the rated design capacity, We
must remember that where there is air flow there is also likely to be "noise flow"
accompanying unless special absorption and/or reflection schemes are implemented.
Scope of Efforts:
Our recommended scope of acoustical design services is as follows:
"'"~'1. We will design and prepare drawings to reduce the fan discharge noise
reaching your property line by 23 dBA. This will be done by the use of
air silencers and or reflections that will not impair the operation of the
system.
2. We will design absorption panels to reduce the noise at your property
line to meet the criteria set out above, while not reducing the necessary
air flow.
3. We will design absorption or enclosures for the compressors to reduce
the noise level reaching your property line per the above noted criteria.
This may or may not be a part of the design elements incorporated in # 2
above.
4. We will design air louvers or silencers as required to prevent the noise
from AHU-I from reaching your property line.
5. We will prepare and provide a "good faith" estimate of the price or
. _ prices that may be charged by a contractor to purchase and install the
system or systems that we have recommended.
6. We will meet with the city of Coppell officials to discuss and explain our
recommendations.
7. We will meet with a contractor ofyour choosing to explain our
recommendations and respond to any questions you may have.
8. We will review and approve, as appropriate, the contractor's shop
drawings and submittals,
9. At the completion of the installation of our recommended remediation
measures we will conduct a final inspection and instrumentation and
issue you a report of our findings.
Fees:
Our fee for the above scope of services is $11,750.00 plus travel related expenses and
reproduction expenses, at cost. We invoice monthly on a percentage of completion
basis and we are able to begin our efforts on this case within five working days of
your notice to proceed.
20,00 09:28a p.~
Joiner Technology Group
Baclq~round Information:
Joiner Technology Group has provided avoustical consulting services W hundreds of
clients, for many types of facilities, since 1954. Since inception, our service
offerings have been expanded to include audiovisual, acoustical and communications
solutions.
Our scope of projects includes universities, corporate/financial companies, religious
institutions, military and government entities, and thc medical industry.
Teamwork is key in our approach to projects. Each project is executed by a multi-
disciplined, dedicated team that addresses the design and implementation in a
comprehensive manner. In-house capabilities include expertise in all aspects of the
communications environment. Our designs are custom formatted to integrate and
augment the services of the architect, interior design and MEP consultants, as
required, for each project.
Our integrated approach and dedication to quality is exemplified by our long-term
working relationships with many clients.
Additional information about our firm and our services is available upon request.
Prelect Team:
The team assigned to this project will be comprised of the following individuals from
Joiner Technology Group:
John Joiner
Principal-in-Charge
John Joiner entered the field of acoustics in 1954. He was the original founder ofthe
company known as The Joiner-Rose Group, Inc.
Specializing in noise and vibration control, Mr. Joiner's work experience
encompasses a broad range of applications, evolving into a multi-disciplined
acoustical capability.
Mr. Joiner has more than 45 years &experience in construction, with 35 years
devoted almost exclusively to acoustic, environment, vibration, noise, and shock-
control problems.
Mr. Joiner worked as a consultant in the design of atomic shock protection devices
and systems for underground missile sites and centers in the late 1950's. In addition,
he has supervised the design and manufacture &vibration, noise and shock-control
hardware.
Mr. Joiner has served as Chairman of a South Texas City Planning & Zoning
Commission. Hc has also prepared, and had adopted, model zoning ordinances of
noise evaluation and control. He has assisted many cities to prepare and adopt noise
ordinances.
Joiner T~mnology Group
Mr. Joiner assists with all phases of acoustical consulting services, encompassing
such parameters as aircraft flyover noise, noise control in commercial structures,
noise control in multi-family dwellings, occupational noise problems in industry,
product development to meet noise and vibration criteria, and vibration analysis and
control.
In addition, Mr. Joiner has conducted many workshops, symposiums and seminars on
acoustics for professional organizations.
Mr. Joiner is a member of the Acoustical Society of America, ASHRAE, Institute of
Environmental Sciences and the Society of American Military Engineers.
Additional support for this project will include:
· Bruce Barnes Project Assistant
· Michael Marsh Project drafting
· John R. Hyink Administration
Yours ~ truly, *'
~ Accepted
Dale