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HomeMy WebLinkAbout1993 08-23 EDAP Regular Session EDA AGENDA CITY OF BROOKLYN CENTER AUGUST 23, 1993 (following adjournment of City Council meeting) 7 p.m. 1. Call to Order 2. Roll Call 3. Approval of Agenda and Consent Agenda -All items listed with an asterisk are considered to be routine by the Economic Development Authority and will be enacted by one motion. There will be no separate discussion of these items unless a Commissioner so requests, in which event the item will be removed from the consent agenda and considered in its normal sequence on the agenda. 4. Approval of Minutes: * a. EDA Minutes - August 9, 1993 - Special Session 5. Discussion Item: a. Earle Brown Heritage Center Chiller (Noise Problem) 6. Adjournment CITY OF BROOKLYN CENTER Council Meeting Date AUGUST 23, 1993 Agenda Item Numbe REQUEST FOR COUNCIL CONSIDERATION ITEM DESCRIPTION: EDA MINUTES - AUGUST 9, 1993 - SPECIAL SESSION DEPT. APPROVAL: Brad Hoffman, ector of Community Development MANAGER'S REVIEW/RECONMENDATION: No comments to supplement this report Co=nentS below /attached SUMMARY EXPLANATION: (supplemental sheets attached ) RECOMMENDED CITY COUNCIL ACTION • MINUTES OF THE PROCEEDINGS OF THE ECONOMIC DEVELOPMENT AUTHORITY RITY OF THE CITY OF BROOKLYN U CENTER IN THE COUNTY OF HENNEPIN AND THE STAI.'E OF MINNESOTA SPECIAL SESSION AUGUST 9, 1993 CITY HALL CALL TO ORDER The Brooklyn Center Economic Development Authori met in special session and wits me ono Y Authority P called to order by President Todd Paulson at 8:12 p.m. ROLL CALL n President Todd Paulson, Commissioners Celia Scott, Dave Rose e, Barb Kalli her g , and Kristen Mann. Also present were City Manager Gerald Splinter, City Attorney Churlic LeFevere and Council Secretary Kathy Kath Stratton. APPROVAL OF AGENDA AND CONSENT AGENDA President Paulson inquired if any Commissioners requested any items be removed from the consent agenda. No requests were made. RESOLUTION NO. 93 -30 Commissioncr Celia Scott introduced the following resolution and moved its adoption: RESOLUTION APPROVING SPECIFICATIONS AND AUTHORIZING ADVERTISEMENT FOR BIDS FOR DEMOLITION OF 6525, 6527, AND 6529 WILLOW LANE NORTH The motion for the adoption of the foregoing resolution was duly seconded by Commissioner Kristen Mann and the motion passed unanimously. APPROVAL OF MINUTES JULY 26-1993 - SPECIAL SESSION There was a motion by Commissioner Scott and seconded by Commissioner Kalligher to approve the minutes of the July 26, 1993, EDA meeting as printed. The motion passed unanimously, with Commissioner Rosene abstaining due to absence. DISCUSSION ITEM 8/9/93 - I - - ACQUISITION OF 5,500 EMERSON AVENUE NORTH The City Manager suggested this item be tabled so it can be discussed at the next work shop. There was a motion by Commissioner Kalligher and seconded by Commissioner Scott to table discussion of the acquisition of 5500 Emerson Avenue North until the next work session. Commissioner Rosene asked if a decision would be made at the work session. The City Manager responded that it would not. Commissioner Mann questioned the status of a purchase agreement. The City Manager explained the purchase agreement was never executed. The motion passed unanimously. Commissioner Scott questioned the status of the demolition of the apartments on Willow Lane. The City Manager. responded specifications will be approved within 30 days and demolition completed before winter. ADJOURNMENT There was a motion by Commissioner Kalligher and seconded by Commissioner Scott to adjourn the meeting. The motion passed unanimously. The Brooklyn Center Economic Development Authority adjourned at 8:15 p.m. 0 Todd Paulson, President Recorded and transcribed by: Kathy Stratton TimcSaver Off Sitc Sccreturial 8/9/93 - 2 - CITY OF BROOKLYN CENTER Council Meeting Date AuQUSt 23, 1993 Agenda Item Number REQUEST FOR COUNCIL CONSIDERATION ITEM DESCRIPTION: DISCUSSION ITEM: HERITAGE CENTER CHILLER (NOISE PROBLEM) DEPT. APPROVAL: Brad Hoffman, Director of Community Development MANAGER'S REVIEW/RECONBIENDATION: No comments to supplement this report Comments below /attached SUM MURY EXPLANATION: (supplemental sheets attached X ) • Monday evening I would like to discuss the status of the noise problem associated with the chiller at the Heritage Center. As a point of reference, the EDA was contacted July 3, 1991, by the PCA about the noise levels affecting the Earle Brown Commons apartment complex. The EDA was directed to submit a plan to correct the problem. In turn, the EDA had Winsor Faricy Architects develop a plan to resolve the noise problem. However, the original plan would have cost the EDA an estimated $45,000. The action taken by the EDA was to implement the plan in stages to see if the problem could be alleviated without spending the money required by the architect's solution. Hence, the first phase was a wall around the unit. The second phase was the completion of an enclosure around the unit. While this has reduced the noise level, the need to get air across the units through a louver system still allows a significant noise level to escape. The EDA has again been contacted by the PCA about the problem. In response, I had David Braslau, a noise control consultant, review the site and make recommendations. Attached are his comments and recommendations. I believe this will resolve the problem once and for all. Including the proposed work, the total cost will be approximately $32,000. I will be available Monday to discuss the history of the problem and the recommendations. RECOMMENDATION: Establish the project and direct staff to obtain quotes for the work. , david braslau associates, incorporated 1 31 3 5th street s.e. - suite 322 - minneapolis, mn. 55414 - telephone: 61 2-331-4571 10 August 1993 MEMORANDUM TO: Brad Hoffman FROM: David Braslau RE: Earle Brown Heritage Center - Chiller Noise Control Recommendations This memorandum describes the results of our noise measurement program and makes recommendations for controlling noise from the chiller to meet MPCA noise standards. Noise Measurement Results A detailed memorandum on the results is included as Attachment 1. The results are summarized below. 7th Floor Balcony The L50 sound level is approximately 4 dBA over the daytime standard for this location. No nighttime use of the balcony is anticipated. Unit 1003 The interior noise L50 was measured at 55 dBA although the open window generally provides 10 dBA reduction. Projecting the measured source noise to the building face at that location in- dicated an L50 65 dBA which agrees with the 10 dBA window reduction. There- fore, the exterior level is 65 dBA which is 15 dBA over the nighttime standard of 50 dBA. Noise Reduction Needed Based upon the noise measurements and calculations, a 15 dBA reduction in noise from the chiller is needed to meet the MPCA nighttime noise standards. Noise Control Recommendations The current chiller enclosure building can be used to provide the necessary sound reduction but will require some major changes. Currently, noise emanates from the louvers on either end and from the hole in the roof provided to relieve heat from the chiller. This is a major concern for any noise control design and has required some careful considerations not originally anticipated. Earle Brown Heritage Center - Chiller Noise Control Recommendations 10 August 1993 Page 2 The air flow of 88,000 cfm associated with the chiller must be accommodated by any silencing equipment. Moreover, it is recommended that this be handled without the need for additional air moving equipment in the enclosure. The recommended design is shown in EXHIBIT 1. The current louvers at either end of the peaked roof would have to be sealed with wood or concrete block. The louver at the east end of the building should be sealed with concrete block. The doors would also have to remain closed during chiller operation. Noise reducing louvers (INTAKE AIR) would be placed along the bottom of the enclosure facing south. An area of 140 square feet is needed to handle the 88,000 cfm with minimal pressure drop (.25 inches) to permit natural draft ven- tilation of the enclosure. This could be accomplished with three units 8' wide by 5 high. The EXHAUST AIR louvers would be placed at the top of the peaked roof facing to the north. This area would also be 140 square feet thus providing for natural draft flow of the heated 88,000 cfm. The same louver configuration used on the side of the building would be used here. Since the louvers can weigh up to 10 psf, some strengthening of the roof may be needed. The roof louvers will lie at 45 degrees to the horizontal but a small lip on the louvers will minimize rainwater penetration. Some penetration of rainwater into the enclosure may occur but should be less than the current configura- tion. It is recommended that Industrial Acoustics Company (IAC) noise louvers (Model LP) be used to ensure satisfactory performance. A brochure on these louvers is enclosed. The inside of the enclosure would be treated with industrial grade quilted fiberglass absorbers than can be attached directly to the concrete block sur- face of the enclosure. All available vertical surfaces inside the enclosure should be treated with this material. This will provide an additional 3 -4 dBA of attenuation and enhance the performance of the louvers. A brochure on Sound Seal absorbers is enclosed. Estimated Cost of Materials Larger louver elements have been recommended to minimize cost. A preliminary cost estimate has been provided by the Horner Company' for 8' x 5 units of $23 /square foot. With a required area of 2 x 140 sq ft, the total cost of the louvers would be 280 x$23 = $6,440. This is a significant savings over using smaller units. -------------------- 1. The Horner Company 915 West Lake Street Minneapolis, MN 55408 824 -2654 ATTN: Tom Horner Earle Brown Heritage Center - Chiller Noise Control Recommendations 10 August 1993 Page 3 The quilted absorption is $2 /square foot. Assuming 400 square feet of this can be applied to the interior of the enclosure, the additional cost would be 500 x $2 = $1,000. Other costs incurred would be the reconstruction of some parts of the enclosure and strengthening the roof to accommodate the louvers. An overall cost for the reconfiguration of the noise enclosure might be on the order of $10,000. From a dollar per dBA reduction cost, however ($666/dBA), this cost is not unexpected since highway sound barriers can cost one -half this much per linear foot to achieve 15 dBA sound reduction. Expected Results With installation of the noise louvers and interior absorption, at least a 15 dBA reduction at the face of the adjacent residential high -rise is an- ticipated. The resulting treatment would be aesthetically pleasing while providing the needed sound reduction. By using natural draft flow (cool air in near the ground and warm air exhaust at the peak of the roof), no additional air moving equipment would appear to be needed. hoffman.mem ws84 y �l ti . t \ 0 0 �, i oil& Minnesota Pollution Control Agenc g Y June 30, 1993 Ms. Judith Bergland 6155 Earl Brown Drive Brooklyn Center, Minnesota 55430 Dear Ms. Bergland: Subject: Noise Survey Results This correspondence is in response to our telephone conversation on June 24, regarding the noise emitted by the cooling unit at the Earl Brown Heritage Center in Brooklyn Center. A noise survey was performed from 2:00 p.m. to 3:00 p.m. on June 21, 1993, and revealed a sound pressure level of a constant 62 dBA, which is above the state standard. The Minnesota Pollution Control Agency Noise Rule ch. 7010 defines the L50 daytime standard as a sound pressure level of 60 dBA that cannot be exceeded for more than 50 percent of one hour at a residential receiver during the daytime hours of 7 a.m. to 10 p.m. During the nighttime hours of 10 p.m. to 7 a.m. the L50 standard is 50 dBA. The 62 dBA sound pressure level that was monitored, is in violation of both the state standards and requires mitigation to reduce its noise level. Enclosed is a copy of the noise survey and the state noise rule. Please respond within 30 days by submitting a written mitigation plan including an estimated time frame for completion. If there are any questions, please call me at (612)296 -7898. Sincerely, Brian Timerson Noise Control Specialist Air Quality Division BT:jmd Enclosures TDD (for hearing and speech impaired only): (612)297 -5353 Printed on recycled paper containing at least 10% fibers from paper recycled by consumers. 520 Lafayette Rd.; St. Paul, MN 55155 -4194; (612) 296 -6300; Regional Offices: Duluth • Brainerd • Detroit Lakes • Marshall • Rochester F rteini nnnrninndv Frnnlnvnr • Pnntnd nn flor. 1orl Pnnnr FORM.WPS;rev.8- 91:ran NOISE SURVEY FORM * DATE: K INVESTIGATOR: SOURCE: f! r - - TEMPERATURE: LOCATION: = - WIND SPD /DRCTN: RECEIVER: HUMIDITY: ' LOCATION: PRESSURE: SLM: MANUFACTURER MODEL SERIAL # CALIB # RATE @ CAL CHECK p( 3 2 <i. ; ? 5 DIAGRI01• - INDICATE.- NOISE SOURCE, NOISE RECEIVER, MICROPHONE LOCATI -,, REFLECTING OBJECTS /OBSTRUCTIONS, AND DISTANCES Ce r Ic i r , __.____ � ao S� � 1 z \ter . .• r OBSERVATIONS f COMMENTS: ' 1 i - I TIME START: '- TIME END: '' DAY OF WEEK: RESULTS IN dBA: f 3 / G AMBIENT L90 L50 L10 L1 Lmax LEQ August 12, 1993 Mr. Brian Timerson Noise Control Specialist Air Quality Division Minnesota Pollution Control Agency 520 LaFayette Rd.N. St. Paul, MN 55155 Dear Mr. Timerson: Thank you for your letter of June 30 and the subsequent telephone conversation we had concerning the cooling unit here at the Heritage Center. s I indicated to ou on the telephone, we y p are still trying to arrive at an adequate solution to this problem. Originally the unit sat unenclosed. Requests were made to create a sight and sound enclosure. Since then we have: partially enclosed the unit, fully enclosed the unit, added the roof, added a fan unit to draw off the ho air generated by the unit's motors, ventilated one angle of the roof to release hot air, left the West doors open to draw enough air to cool the unit. Since your letter we have hired a consultant to look at the problems inherent to the unit and provide a recommendation that will resolve the problem once and for all. The final opinion is not in as yet. When we have that report I will be in touch with you again to update the status. Should you have questions, please do not hesitate to contact me. Sincerely, Judith L. Bergeland General Manager JLB:pmh Enclosure op Brad Hoffman