Attachment 4 - Coolidge Acoustics.PDF

REPORT

THE COOLIDGE AUDITORIUM

AND

RELATED SPACES - JEFFERSON BUILDiNG, LIBRARY OF CONGRESS

FOR THE OFFICE OF THE ARCHITECT OF THE CAPITOL

GEORGE C. IZENOUR ASSOCIATES, inc.

October 1 1 1991

Final Report from George C. Izenour

To: Mr. James E. Ellison FA1A Assistant. to the Assistant Architect Office of the Architect of the Capitol Washington. D. C. 20515

Subject: Report on findings and certain recommendations by this office assisted by the office of John Altieri, Mechanical and Electrical Engineers concerning room acoustics, ambient noise conditions, technical back-up equipment and systems for rigging, lighting, sound recording, sound playback, sound reinforcement, video mon i toring and commun i cations, mechanical a irhandHng and airconditioning, electrical distribution and plumbing systemsperta in I ng to sped ftc archi tectural rearrangements, remodel ings, restorations and structural modifications of the Coolidge Auditorium located in the Jefferson Building, The Library of Congress.

in addition to the Coolidge Auditorium, it was also requested that 1.k% hb, Fb A lap4 ia .A uIl VI I GIV GIi.CU ijy UI VI li.C VI JVIIII PII.II I, I VIYV QIIU comment on acoustical and related conditions pertaing thereto in the lobby of the Coolidge and the adjacent Wittall Pavilion and the remotely located recording studio.

Modus Operandi: As of this date I have made four visits to the jobsite. The initial visit on May 23 was for the purpose of getting acquainted with the job conditions and the personnel. The second visit on July 29,30 &3 I last, in company with my associates, achieved overview of the physical plant and at that time extensive acoustical measurements were also made.

Subsequent verbal comment by me, In conference, during the third visit on August 21 last attended by personnel both from your office and from the music division of the Library. with the help of graphics and an architectural model I personally explained the overall findings and made certain recommendations, (outlined below), and which at that time were discussed at length and in some detail.

The aforementioned graphics and the architectural model.are already iii your possession. The fourth visit on October 2 last, In company with Mr.

John Altierl, achieved a more detailed assesment of the mechanical and electrtcal systems.

The body of this report is divided into four parts

( 1 ) Acoustical Measurements and Recomendations Concerning the

Separate Facilities

(2) Recommended Architectural and/or Structural Modifications to the Coolidge Auditorium

(3) Recomended Equipment arid Systems and a Sudget Estimate

(4) A proposal for continuing consultation and engineering services by this office.

I ACOUSTiCAL MEASUREMENTS AND RECOIIIENDATIONS (Refer to the sketches and the model for architecUiral and structural modifications, and to Appendix A for tabulation of reverberation times, reverberation curves and background ambient curves.)

This part of the report is based on acoustical measurements taken by personnel from this offlce on July 30 & 3 1 last. These measurements are concerned with: reverberation times of the auditorium, both occupied and unoccupied, early and late acoustical reflections and background ambients of the Coolidge Auditorium. Measurements of reverberation times and background ambients only were taken in the Coolidge Lobby, the Wittall

Pavilion and the Recording Studio.

( A) Coo I i dge Aud i torium It is generally appreciated that this facility is a superior recital and chamber music hall. Except for the minor corrections suggested below the acoustical measurements are considered as scientific confirmation of the haIrs sterling reputation among musicians and music lovers..

Commentary on the acoustical measurements with emphasis on certain interrelating aspects pertaining thereto.

(1) Reverberation Time (RT)

The measured diferences, between occupied and unocupied in RTs at mid frequencies average .5 sec. yielding an RT of about 1.4 sec. with an audience.

The decay curves for all seats are both smooth and uniform. These basic acoustical characteristics are those of a highly articulated audttorlum and considered Ideal for recital and chamber music.

(2) Analysis of Primary and Secondary, 8oth Early (desirable) and Late (undesirable), Energy Reflections

(a) Except for a lack of early flrst overhead energy reflections for the first seven rows, the early first reflections from the ceiling and side walls for all other seats are superb.

Solution: Correction of this condition in the fIrst seven rows is effected by: ( 1 ) closing the now obsolete ventilation grill In the ceiling bay adjacent to the proscenium, (2) eliminating the permanent overhead stage drapery (teaser), (3) restructuring the shell ceiling. (Refer to the model and also see below for further explanation).

(b) There are two observable late energy reflection conditions that should be corrected.

( 1 ) Depending upon location of the sound source on the stage there are a series of late secondary energy reflections in certain of the side seats adjacent to both side walls. This condition is caused by the late arrival of secondary energy reflections occuring between the opposite side wall and the continuous. concavecurved surface of the rear wall.

(2) There is a concentrated late first energy reflection at the back wall of the shell. This is caused by the late return of concentrated first- reflected energy from the continuous concave curved surface of the rear wall.

Solution: There is a single simple remedy for both conditions. I.e. A slightly double convex curving of the surfaces (in both the horizontal and the vertical planes) within the rear wall panels will break up the continuous concave surface of the wall, thereby diffusing the reflected energy and eliminating both conditions.

NOTE: The measurements produced no hidden surprises. All three of these minor acoustical flaws were anticipated. Each was revealed in a prior detailed study and analysis of the room geometry.

Conferences with both executive and operations personnel of the music department reveal a desire to expand as well as enhance the overall use factor of the Coolidge for the recording of music performed on the stage but without an audience present and for stage speech (lectures, public meetings etc.)

Operations personnel also related that, over the years, a series of improvisations intended to alleviate these conditions, in order to better facilitate both recording from the stage and for stage speech had been tried but with small success. To this end and to better demonstrate a recommended built-in scheme that is straightforward In design and simple in operation and at the same time is both flexible and programmable for achieving a solution to the problem; this office reacted by building the architectural model alluded to above. The model is intended as a three dimensional demonstration of a scheme for realizing three separate operational modes for ( 1 ) optimizing the room acoustics for recital, (2) optimizing the room acoustics for recording on the stage without an audience, (3) optimizing the room acoustics for stage speech from the stage with an audience.

Statement of the Problem: For both a workable recording mode without an audience and a workable stage speech mode with an audience the auditorium is acoustically too live (reverberant). Particularly for recording both the reverberance and the return energy to the stage, which is normally absorbed byan audience, is simply overwhelming without an audience. For stage speech, with an audience a similar situation prevails, but to a lesser degree. These problems are therefore related and a solution dictates application of certain preprogrammable (variable) means for either reducing the volume, or adding absorption and/or by a combination of both to affect a reduction of both reverberance and return energy in the appropriate amounts for the recording and the stage speech modes.

Solution: It is therefore recommended that:

C 1 ) The stage acoustical shell, incorporating an upward and forward sloping roof as shown in the model, be rebuilt (necessarily of fire resistant materials) and that a downstage portion of the shell side walls and roof be hinged outward and upward respectively in such a way as to accomodate the on and off stage movement of a redesigned stage drapery system essential to the stage speech mode, as shown in the model.

(2) the interposition of a preprogrammable (variable) absorption system, consisting of an array of above ceiling mounted, roll-up velour draperies both for adding absorption and for reducing the apparent acoustical volume of the room. This system is located In the third bay immediately behind the second ceiling beam in the auditorium as shown in the model.

Result: The rebuilt acoustical shell and movable stage drapery system will provide either an acoustically hard (reflective) sending end of the auditorium essential for the recital mode or an acoustically soft (absorptive) sending end of the auditorium essential for the stage speech mode. The overhead absorption system In the ceiling of the auditorium will be programmed to duplicate either the reverberance and return energy conditions of the occupied auditorium for the recording mode or the proper reverberance for the stage speech mode.

NOTE: With this absorption system in place it is also possible to achieve varying degrees of acoustical liveness conditions fOr rehearsal that are between the two preprogrammed extremes for recording and stage speech.

The rebuilt acoustical shell and the flexible stage drapery system, now articulated with each other, also will provide both a continuous and a contiguous overhead acoustically hard reflecting surface for delivering the missing overhead first energy reflections to the first seven rows of the auditorium. This phenomenon was alluded to in the acousitcal measurements section above.

Sound Reinforcement for stage speech While the room acoustics, as modified above for stage speech, will be entirely satisfactory for experienced public speakers who understand how to project the speaking voice and will not need electronic reinforcement, it is essential for the so-called “microwatters who do not project the speaking voice and require electronic reinforcement. To that end, a redesigned electronic sound reinforcement system with central overhead loudspeaker cluster, which pivots up Into the ceiling and out of sight for the recital mode, Is Included. (refer to model)

A redesigned stereo play-back system for music Incorporates loudspeakers as presently mounted behind the grilles on either side of the proscenium.

Additional Acoustical Considerations:

(I) Background noise (ambient) was measured In several locations both with the air handling system turned on and with It turned of f (see Appendix A for curves) revealing an unacceptable level of low frequency noise emanating from the air handling system. This noise originates In the mechanical room underneath the lobby wherein are located the air handling fans.

This noise is getting into the auditorium through the supply ducts In the ceiling and the return air plenum under the seating. insertion of attenuators in both the supply and return air ducts will solve this problem.

Air velocities were also measured at the ceiling diffusers and found to be acceptable for an auditorium. Because the fans are not isolated for shock and shear from the building structure there is reason to believe that a portion of this noise is also structure born. Assisted by Mr. Jophn Altieri these problems were investigated further during the October 2nd, visit.

NOTE: Because the auditorium, the lobby and the Wittall Pavilion are all three connected to the same air handling system all three exhibit similar background ambients. The existing ambient is satisfactory for the lobby, moderately so for Wittall Pavilion but unacceptable for the auditorium.

NOTE: A separate opinion from Mr..John Altieri concerning the mechanical and electrical condition of the airhandi ing and airconditioning system and certain remedial recomendations pertaining thereto is contained in this report as Appendix B

Other sources of noise that should be neutralized:

( I ) The fire exit door in the right wall leading out into the courtyard should be isolated by addition of a shallow masonry-structured foyer on the outside of the building and an additional set of doors installed thereto.

(2) The double doors leading into the return air plenum from the adjacent guard’s room in the basement should be bricked up.

(3) The backstage doors, on both levels leading Into the building corridors, are each a source of outside noise but this problem is part of the larger problem of modernizing and rearranging the stage itself. (see below)

(4) The public lobby is also a source of noise, but it is recognized that this cannot be entirely neurtalized. Gaskesting the doors leading Into the auditorium wI 1 1 help to better sound Isolate the two spaces. The lobby is also too reverberant. A rug on the floor and sound absorptton batting installed behind a sound transparent fabric In the wall panels would be a decided help In alleviating this condition

(NOTE) Of interest in passing Is that the empty lobby has the same reverberation time as the unoccupied auditorium.

(8) WIttall Pavilion it is our understanding that this facility serves three purposes, ( 1 ) Storage for the Coolidge Collection of Musical instruments

(2) Receptions and Social Gatherings.

(3) Both an overflow and waiting area for the audience attending concerts in the auditorium. There is a stereo-audio-video system that pipes the stage performance into the room. (In this connection it is suggested that a video camera with remotely operated zoom lens be mounted in the exisiting projection booth for this purpose.) This office did not participate in discussions pertaining to instrument storage. The room as presently furnished has a reverberation time of about one second at mid frequencies and in our judgment is satisfactory for gatherings as well as for overflow and as a waiting area for the audience.

(C) The Recording Studio My remarks and recomendations concerning this facility reflect the requirements enunciated by Mr. John Howel 1, Chief Recordist in the Music Division of the Library. My understanding of the overal 1 situation concerning recording, and most particularly in light of the proposed remodeling of the Coolidge to make it serve as the principal recording studio for live music both with and without an audience, and at the same time to retain and enhance the acoustical excellence of the Coolidge for its primary purpose of public performance. Use of the remote recording studio for live recording will be minimal and no attemptwill be made to structurally isolate the facility. Forremote handling of the live activities originating in the Cool idge, rerecording and dubbing , and to provide both a shop for maintaining and a space for storage of recording equipment and instrumentation, all that will be required is to either replace altogether or quiet the existing air handling system, rewire the spaces for power lighting and control and partition as directed by operating personnel.

2. RECOMMENDED ARCHiTECTURAL AND/OR STRUCTURAL MODIFICATiONS TO THE COOLIDGE AUDITORIUM (Refer to architectural model and sketches in plan and section)

General Statement: Except for restorat I on and re i nstalllng of the ex i sting seating (reupolstering, tightening up of the stanchions, bottoms and backs and replacement of parts as required) plus the minor architerctural changes for overcoming minor faults in the room acoustics as identified and recommended above, the auditorium, In my judgment, needs only to be repainted and the floor covering replaced.

The stage, the backstage technical facilities, the orchestra pit, the below stage instrument storage and the dressing rooms, the I ighting and rigging occurred sparnodica)1y over many years. (To put It in the vernacular the place has been literally bandaided almost to deathN) 5y contemporary standards the entire stage and the backstage technical operation can only be described as primitive In the extreme.

The recommendations by this office for upgrading the backstage are based on a virtually complete redesign of the facility and upgrading of the technical operation by modernizing the stage technology as indicated In the sketches and as demonstrated three dimensionally In the model.

The following changes, deletions and additions are recommended:

I . The doors to the right and left of the proscenium leading Into the auditorium from the stage and the shallow stairwells in the stage floor pertaining therto present both a severe technical impediment to backstage operations and. are also a hazard to personnel. in light of the fact that right and left open steps from the auditorium to the stage already exist but a few feet away these redundant and hazardous architectural elements should be eliminated.

2. For the reasons given it Is recommended that the acoustical shell should be rebuiltin the manner shown in the architectural model.

3. It is recommended that the orchestra pit be restructured and equipped with a multi-purpose pitapron lift and an articulated (tracked) seat wagon in the manner shown In the architecturalmodel.

This lift founded on a depressed slab provides maximum flexibility to the sending end of the auditorium. ( 1 ) adds an apron to the stage,

(2) together with the seat wagon it provides the means for easy manipulati ion of the one row extension to the auditorium, (3) an orchestra pit, (4) a means of vertical transport (see below)

4. The existing piano lift Is outmoded and should be eliminated In favor of the multi-purpose pitapron lift mentioned above. The below stage room should be restructured, a i r condit I on i ed and humIdity controlled for proper instrument storage with double door access to the aforementioned pitapron lift for movemet of pianos etc. in and out of storage, to and from the stage.

5. The existing backstage dressing rooms, on both levels, represent the principal Impedement to any semblance of ever achieving efficient backstage techinical operations and it is recommended thqt they be reconstituted elsewhere. These relocated dressing rooms should also be sound isolated from each other and from the stage to provide orivt warm-un fcil1tis for th musicians and they should also recommended that these expanded and modernized facilities for dressing and warm-up should be relocated within an added story above the stage as shown in the architectural model.

6. Once the dressing rooms are removed from the stage volume a gallery devoted exclusively to technical operations can then be built above and surrounding the acoustical shell as shown in the architectural model.

7. Present vertical communication and transport within the stage house is poorly located, is not sound isolated and is hazardous to personnel. With a restructured stagehouse and acoustical shell and relocated dressing rooms both a new acoustically isolated staircase and an elevator from basement to the suggested relocation of the dressing rooms above the stage can be located as shown in the architectural model. It is axiomatic that for efficient technical operation as well as convenient artistic use of the stage it is imperative that the wings of the stage be kept open and clear.

8. I t is recommended that a mechanized stage rigging system for handling the stage draperies, articulation of the roof of the acoustical shell for on and off” stage operation of the stage draperies and the overhead stage lighting batten should be provided and the existing rolF-up projection screen be reinstalled withIn the up and ‘down” stage limits of the drapery system. (refer to the architerctural model)

9. A new stage lighting system, complete with individual switching dimming and master controls for the down lighting in the roof of the acoustical shell, stage and auditorium lighting and inclusive of right and left mechanized fore-stage lighting booms that pivot up and out of sight into the attic above the auditorium ceiling when not in use In the recital mode are an essential element of this system. (refer to the architectural model for approximate sizing and location)

1 0. Rewiring of the stage and installation of the new systems for the ri ggi ng, l I ght ing, sound re inforcement, record ing, p 1 ayback, video and communicatlonsand their associated networks and controls as required completes rhe technical revamping of the stage. (It Is intended that these networks and controls will be worked out In detail with the complete knowledge, advice and cooperation of the technical staff of the music department of the library)

NOtE: Consonant with the aforementioned structural changes It Is Intended that all recordino. Dlavback moniterino. staae and auditorium llqhtlnq and provided by the new technical gallery above the stage with appropriate electrical, recording, video and communications links extended to the Wittall Pavilion and the present recording studio as required. Above all else this scheme frees up the stage wings for the performing artists and provides both off stage space and a now non-existant ease of movement for handling with a minimum of operating personnel the positioning of musical instruments, chairs, music stands etc. before,during and after performances and recording sessions. If and when all of these aforement I oned arch i tectural add i t I ons and structural, electrical and mechan i cal mod i f I cat 1 ons are achi eyed w i th i n the stagehouse and the auditorium together w i th the reinstallation, replacement and/or modification of the various systems and equipment as enumerated In section 3 are accomplished and since the entire facility will then be a self-contained unit that is sound isolated as a whole both from the outside and from the rest of the building&d the separate parts of which are also sound isolated from each other, It is my judgement that the music division of the Library w i 1 1 then have one of the finest combined performace and recording facilities in the country.

3. RECOMMENDED EQUIPMENT AND SYSTEMS AND A BUDGET

ESTIMATE (estimates include installation except as noted)

,iuuIi,vI lviii riyyiiiy

S Hinged Central Loudspeaker Port-------- 10,000.00

* Hinged Front Lighting Booms (2)--------— 20,000.00

* Roll-up Acoustical Drapery Assenbiles (5) 25,000.00

* Orchestra pit-stage apron lift 125,000.00

* Seat wagon 20000.00

$200,000.00

*Includes installation of machinery only, Concrete work, flooring of lift platform and seat wagon and ekiectrical connections by others

‘Includes installation of machinery only. Framing out of ceiling and electrical connections by others.

Stage Rigging Power Operated Front Curtain S 6,000.00

. Traveler Curtain------- 6,000.00 . U Teaser Curtain---------——— 5,000.00 $ . Light Pipe I 4,000.00 N • Articulation of the Shell Roof I 4,000.00

Reinstallation of the Picture Screen--—-— 500.00 ---------- 45,500.00

Stage and Auditorium Lighting System (electrical connections by others)

Dimmer Bank (48 - 2.5 KW Dimmers----- S 14,000.00

Lighting Console 3,000.00

Stage Managers and Rigging Console---—— 4,000.00

Distribution Equipment—---— 5,000.00

Stage Lighting instrumentation --------— 27.00000

---------- $53,000.00

AudioVideo Systems (installation and electrical connections by others) intercom 3,500.00

Monitor/Paging-----—-—-——---—-— 15,000.00

Speech Reinforcement system-------- 45,000.00

Video . --- 19,500.00

$83,000.00

TOTAL $38 1 ,500.00

Additional Audio (recording) Equipment Listed by Mr. Johm Howell in memo to this office dated 21 Aug. 91 NOTE: This equipment is considered to be an addition to the existing recording sytem and is therefore not integral to the building.

1. Neve Analogue Mixing Console .5455-16---— $31,495.00

2. Equipment Racks AMCO 800--7240 (Blue)--- 1,500.00

3. Digital Concert Mixing Console(Neve DTC- 1120,000.00

4. AudIo Line Drivers Signal Distribution---- 10,000.00

5. Pan and Tilt Microphone Adjusters V1CON-- 2,800.00

(4) A proposal for continuing consultation and engineering services by this office pertaining to the proposed restorations and/or remodelings inclusive of: the preparation of bidding documents (draw irigs and spec i f fcations), review of contractors submissions, periodic jobsite Inspections as required during the course of construction and a final checkout of all systems and acoustical measurements at the conclusion of construction for the equipment and sysiems listed In section 3.

Please accept the following as an outline of Intent with respect to this office continuing to serve the Office of the Architect of the Capitol as theater and acoustics consultant for remodeling of the Coolidge Auditorium, The Wittall Pavilion and the Recordung Studio in the Jefferson Building, The Library of Congress

The continuing work of this office, based on the sketches in plan and section and the architectural model of record, will be performed in two phases namely: Production of Bidding Documents and Construction.

BE ASSURED THAT THE WORK OF THIS OFFICE WILL BE FULLY COORDINATED

IN CONFERENCES, BY MAIL AND PHONE WITH THE DES1ONATED PERSONNEL OF

YOUR OFFICE, THE ENGINEERS OF RECORD AND THE TECHNICAL STAFF OF THE

I IRPAPV

PRODUCTION OF BIDDING DOCUMENTS

(a) Produce a complete set of reproducable tracings, on mylar drawing stock of the above listed systems and equipment. It is understood that for the proper placement of the above listed systems and equipment within the architecture your office will furnish this office with as built drawings in plan and section, eIther as reproducable seplas on mylar to specified scales or on disc for CAD.

Al I original tracings become your property.

(b) Furnish a complete set (one typescripted copy) of specifications for the above listed systems and equipment.

(c) Produce architecture and engineering related drawings showing positioning of the above listed equipment and systems, indicating structural reactions, electrical circuiting and connections pertaining thereto

(d) it is understood that final responsibility for the structural integrity of all secondary structures, sizing of all electrical conductors, conduit and circuit protective devices and carrying out of all mechanical systems ambient noise criteria rests with the structural, electrical and mechanical engineers of record.

(f) This office will assist, as required, in evaluating the bids on these systems and equipment by qualified manufacturers and installers for the above listed systems and equipment.

CONSTRUCT I ON

(a) Review and approve, subject to final approval by your office, of all contractors shop drawings related to the above I isted systems and equipment installations.

(b) Make periodic jobsite inspections as required.

(c) At the conclusion of construction, check out all sytsems and equipment listed above and make all acoustical measurements concerning room acoustics and background ambients.

FEES

The charge for these services is a flat fee of $48,000.00 not including reimbursible expenses which will be invoiced at cost as they occur. The fee is payable in installmants as follows:

Bidding Documents--------------------------- 28,000.0O.

Payable in two equal intallments of $14,000.00 The first installment upon 25 % completion and the second upon 1 00% completion and at the conclusion of the bidding period

Construction- $20,000.00 Payable in two equal installments of S I 0,000.00 The first installment at 50% of completion and the second upon acceptacê of the builiding by the owner.

it Is the recommendation of this office that the complete systems and equipments as outlined above be designed. However, It is recognized that due to budgetary limitations either an overall reduction in scope or the phasing or certain of these elements will be necessary. To this end this office will give whatever assistance deemed necessary to the office of the architect and the operations personnel

We would consider it a pleasure to continue serving your office as theater and acoustics consultant for this most Interesting project.

Respectfully Submitted.

1’

APPENDIX A

LIBRARY OF CONGRESS

REVERBERAT I ON T flIES

COOLIDGE AUDITORIUM

MEASURING LOCATION 250 Hz 500 Hz 1 kHz 2 kHz

WITHOUT AUDIENCE

SIDE AISLE ROW A 1.40 1.35 1.65 1.70

SIDE AISLE ROW H 1.45 1.20 1.45 2.00

SIDE AISLE ROW N 1.50 1.35 1.65 1.75

SIDE AISLE ROW T 1.55 1.50 1.60 1.70

RIGHT WALL ROW B 1.85 1.45 1.90 N/A

RIGHT WALL ROW F 1.85 1.45 1.75 1.70

RIGHT WALL ROW L .2.00 1.50 1.80 1.70

RIGHT WALL ROW T 2.20 1.45 1.50 1.60

CENTER ROW A 1.50 1.40 1.50 1.70

CENTER ROW F 1.85 1.45 1.55 1.70

CENTER ROW N 1.60 1.50 1.55 1.70

CENTER ROW T 2.00 1.25 1.75 1.80

WITH AUDIENCE

SIDE AISLE ROW A N/A 1.30 1.60 1.10

SIDE AISLE ROW H 1.25 1.25 1.25 1.10

SIDE AISLE ROW N 1.25 1.15 1.25 1.25

SIDE AISLE ROW T N/A 1.15 1.25 1.35

RECORDING STUDIO

MIX CONSOLE 0.50 0.45 0.45 0.45

WHITTALL PAVILION

ROOM 2/3rd POINT 1.00 1.00 1.00 0.80

LOBBY

ROOM CENTER 2.00 1.65 1.45 1.15

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APPENDIX 6

John L. Altieri ConsLlItinZ Ezvineers

REPORT ON

THE COOLIDGE AUDITORIUM

AND

RELATED SPACES AT THE LIBPARY OF CONGRESS

FOR THE ARCHITECT OF THE CAPITOL

Prepared By John L. Altieri Consulting Engineers

31 Knight Street Norwalk, CT 06851

October 7, 1991 onstilting Eiigineers

INDEX

I. EXECUTIVE SUIOtA.RY

It. EXISTING CONDITIONS

III. PROPOSED SYSTEMS HVAC

IV. PROPOSED SYSTEMS ELECTRICAL

V. PROPOSED SYSTEMS PLUMBING AND

FIRE PROTECTION

VI. BUDGET COSTS

John L. Aitieri (oiu1ting Enziiieers

THE COOLIDGE AUDITORIUM AND LIBRARY OF CONGRESS

RELATED SPACE

I • EXECUTIVE SUNMARY

The Coolidge Auditorium, the Remote Recording Studio and the Whittall Music Pavilion were constructed between 1925 and 1939. The electrical systems and air conditioning systems were upgraded between 1959 and 1966.

A aor upgrading of these systems, concurrent with the upgrading of the architecture and acoustics, appears appropriate since there are apparently a number of defects in these systems and they are approaching the end of their useful life of twenty-five to thirty years.

In addition, acoustical measurements indicate inappropriate noise levels generated by the mechanical systems. Exposed lighting units and wiring systems create some potential hazards and code related short comings.

System changes are also required to meet a new program for housing instruments in museum quality controlled environments in the Whittall Music Pavilion and in the piano storage area being created below the stage area.

New spaces being created by the architecture must also be conditioned and powered.

The Recording Studio systems generate an unacceptably high noise level from both the air conditioning systems and the mechanical ballasts for the fluorescent lighting fixtures.

Preliminary order of magnitude estimated for mechanical and electric work as follows:

The Coolidge Auditorium: Mechanical 250,000 Electrical 150, 000

The Whittall Music Pavilion: Mechanical 120,000 Electrical 40,000

Recording Studio: Mechanical 40,000 Electrical 40 000.

Total Budget $640,000 q

Cüiitiltiiig Engiiiers

THE COOLIDGE AUDITORIUM AND LIBRARY OF CONGRESS

RElATED SPACE

It. EXISTING CONDITIONS

A. The Coolidge Auditorium

The system designed in 1960 by Guy B. Panero Consulting Engineer was installed as designed except as noted below.

The equipment has been well maintained and certain changes have been made including a new high efficiency motor, new control valves, the local chiller was removed when the central chilled water supply for the building was installed and a chilled water cooling coil was installed in place of the direct expansion coils shown on the drawings.

The preheat coil is installed ahead of the filters on the fresh air inlet only.

All asbestos related materials have been removed from the machine room. • •

The filter is a low efficiency roll filter which was well maintained and manually operated.

In an attempt to reduce noise, portions of the plenums had been lined with a nonporus foam material.

The fan is rated on the drawings at 14,250 CFM and duct velocities vary from a maximum of 1,500 feet per minute at the fan discharge to 1,000 feet per minute at the diffusers. We assume the system has been balanced to the design.

The existing ductwork is all internally lined as is the limited return and fresh air ductwork.

Fan and casing are adjacent to the crawl space under the theater. The crawl space is open to the theater from return grilles under the stage and mushrooms in the legs of the seating. Approximately 50% of the seats have returns through the floor to the under floor space.

This system serves not only the auditorium but both the lobby and the entire back stage area.

The close proximity of the fan to the house creates excessive noise as measured by Mr. George Izenour.

CO11SUItiflZ Engiiers

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The present system is provided with 42° chilled water designed for a 20° temperature rise. The fan appears to be “bottomed-out” on its isolators which is creating some structure born-noise.

The fan wheel does not appear to be well balanced which could also be causing some noise. An existing access door on the fan could permit close inspection of the fan condition.

There is no excessive air motion in the theater and there was no indication that the system did not meet the air conditioning loads in the space.

The existing ductwork both on the roof and in the machine room appeared to be in good condition.

There is a single control point controlling all spaces.

There is an auditorium exhaust fan and projection booth exhaust fan each opening directly into the theater.

Existing lighting fixtures are maintained using a cherry picker located on the auditorium floor. They appear to be well maintained. Step lights and wall sconces provide additional house lighting. All stage lighting is exposed on the ceiling of the house and in the stage area.

Speakers are exposed on the ceiling of the auditorium.

Wired microphones are exposed on stage. Exit lights are located at all exists, they should be checked for code conformance. Sound equipment is located on stage right together with lighting control systems. Mechanical lifts on stage lift piano’s from storage beneath the stage.

B. The Whittall Pavilion

The system appears to be installed as shown on the 1938 drawings prepared by M.F. Hoppe Mechanical Engineer with the exception of A/C Unit #1 which was serving the cases.

The main system was not operating at the time of our inspection, however, the system as installed is operating as a comfort air conditioning system.

Chilled water coils were substituted for the brine coil

Consulting Engineers

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called for on the drawings.

The supply grilles are as shown on the drawings above the ccve.

An 8” X 4” grille in the office south of the Salon was fed from a separate system. (Not as shown on drawings).

C. The Recording Studio

The recording studio had a central air handling unit located in the cellar which supplied air to the studio through a system of overhead ductwork. This air unit had been upgraded and was operational. The ductwork distribution was exposed and not well arranged for the studio. In addition, there were high velocity induction units located under windows in the studio space. These units were generating high frequency noise at very high levels making recording in the studio extremely difficult.

Fluorescent lighting ballasts were creating very high volume low frequency noise in the studio as well.

Supplementary incandescent lighting in the recording studio was used during recording sessions.

(:flflsflltiflg Engineers

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III. PROPOSED SYSTEMS HVç

A. The Coolidge Auditorium

In order to meet current acoustical standards and to accommodate the proposed architectural changes, including the recessing of lights and the concealing of velour drapes for recordings without an audience, we propose to provide the following modifications to the HVAC system in the auditorium (System #1).

1. Replace the existing air handling unit with a new system consisting of the following components:

a. A new casing constructed of double wall acoustically treated plenums. This casing will house new high efficiency filters of the bag type, new preheat, cooling coil, reheat coil and steam humidifier, a new fan enclosed in the casing. This fan will be isolated from the structure with spring isolators.

b. New direct digital control (base specifications Staffa) system to permit accurate control of both temperature and humidity in the auditorium including new control valves and piping at the coils.

c. Variable speed motor on the fan to permit reduced air flow during particularly sensitive performances.

d. Automatic dampers to limit the quantity of outside air during non-performance periods.

This system will operate as required during occupied periods only.

e. Controls from the central computers with alarm points.

2. Add the following acoustical treatment:

a. The addition of acoustical treatment at the fresh air intake from outside.

COflSt1ItiflZ Engineers

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b. The addition of acoustical treatment at all doors entering the plenum below the house.

C. The addition of acoustical treatment at the door leading to the monitor which is open to the house.

d. The addition of acoustical treatment at the exhaust fans on the monitor roof and the exhaust fan in the projection booth and interlocking the exhaust fans with the supply fans automatically during occupied cycle.

e. The addition of sound absorbing material to the mechanical equipment room walls and ceiling will be considered.

f. Add attenuators on the supply and return ductwork as required.

3. Modify the ductwork as follows:

a. Separate the supply to the lobby and the stage from the main air handling unit.

b. Reduce the total air proportionally.

c. Modify the ductwork in the ceiling of the house to accommodate the recessed lighting and recessed acoustical baffles.

d. Inspect and replace any ductwork which is deteriorated. (It was noted that almost all ductwork was in good condition during the preliminary inspection.)

e. Re-support ductwork in the plenum from the floor of the plenum using vibration isolation.

f. The new casing will not contact the wall between the machine room and the plenum.

Consulting Eirziiwers

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4. AcId two new systems:

System 2 will provide museum quality conditions in the piano and instrument storage room under the stage. This system viii maintain 72°? 50% relative humidity on a year round basis using high efficiency air filters, low noise level fans, and minimum ductwork to maintain the space under the stage continuously at . stable conditions.

System #3 will service the new stage house. This system will be a comfort system providing multiple zones for each level of the stage and meeting the conditions necessary to absorb the heat generated by on stage lighting and the energy given off by the electronic communications and recording equipment housed in the stage house.

B. The Whittall Pavilion

In order to meet the desires of the staff to provide for stage and use of valuable musical instruments it is proposed to provide a museum quality system to serve the- Whittall Pavilion, Room 6-110 to the south, and the lobby of the Coolidge Auditorium to the north.

This new system will be operated 24 hours per day 7 days a week to maintain conditions at 72°? 50% relative humidity on a year round basis. The existing system will be replaced with a new unit in the same location and the existing ductwork will be reused as much as possible.

Three separate zones will be provided from this machine to maintain proper temperatures in each space. Return air humidity control will maintain space humidity conditions.

New coils, fan, filters, and controls will be provided.

The spaces will have to be provided with vapor barrier paint and double glazed windows in order to maintain conditions on a year round basis.

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Existing ducts will be used as much as possible, however, the supply outlets in the Whittall Pavilion will be modified to provided slot diffusers out of normal site lines.

C. The Recording Studio

The recording studio must be modified to provide an acoustically sound system which will meet the loads generated by the space and the electronic equipment therein.

The present system will be studied and reused if possible or replaced with a system of sufficient capacity to meet the studio loads.

This system should operate as a process system to keep the recording equipment in a controlled environment on a continuous basis. The loads and conditions required should be established by the users, and provided to us for study and implementation of an appropriate system.

The present system, which is a combination of a central system located in the basement below the recording studio and three induction units which generate excessive noise could be modified on a temporary basis to suit lowered budgets by shutting down the induction units during recording sessions. This would limit the capability to meet loads but would make the system acoustically sound.

Automatic blast gate dampers and downstream attenuators could be used.

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Iv. PROPOSED SYSTEMS ELECTRICAL

A. The Coolidge Auditorium

The auditorium electrical systems will be designed by George Izeriour. From these systems conduits arid raceways will provide a complete system of theatrical apparatus including but riot limited to:

House Lighting Stage Lighting

Dimming Control Power for Theater Equipment and Lifts

Power for HVAC Power for Elevators Emergency Lighting • .

Exit Lighting Fire Alarm System Security System Audio Amplification Systems Queuing System.

Recording Syitems Sound Systems Company Switches Follow Spot and Projection Equipment Closed Circuit Television Low Voltage Controls Telephone Systems

Existing raceways will be used where practical. New wiring will be provided throughout. Existing lighting fixtures will be removed, refurbished and reinstalled.

B. The Whittall Pavilion

Electrical systems in the Whittall will be modernized.

New fixtures will replace existing fixtures where appropriate. New wiring and switches will be provided.

Security and fire protection will be reviewed.

Communications systems, closed circuit TV, telephone and sound systems will permit use of space as a salon for latecomers and overflow crowds. Since the space will contain valuable instruments and documents security will be essential. Detailed studies of requirements will be required to establish an appropriate electrical program for this space.

CoflsLiItiflz Enzineers

THE COOLIDGE AUDITORIUM AND LIBRARY OF CONGRESS

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C. The Recording Studio

Electrical systems in the recording studio will be provided to meet the power requirements for this space.

Consideration should be given to develop a detailed program to meet the users present and future needs.

Conduit and wire for interface with The Coolidge Auditorium, The Whittall Pavilion and other spaces should be considered.

John L. Aitieri C( )1 hil ltii ig Engii’ers

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V. PROPOSED SYSTEMS PLUMBING MD FIRE PROTECTION

Existing plumbing systems should be examined to assure that they will meet the needs of the project. My inspection did not involve plumbing systems, however, it would be appropriate for the Architect to inspect all plumbing systems within the borders of the project to determine their condition and their potential for generating noise within the theater. A program should then be established for the rehabilitation of plumbing systems.

Systems incidental to the mechanical systems will be accommodated in our design.

We were directed that the fire protection systems including sprinkler, standpipe and possible halon would be designed by the Architect for the Capitol Staff.

COflSlIItiIMZ Engineers

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VI. BUDGE1 COSTS

We anticipate based upon the above outline costs in the order of magnitude as follows:

The Coolidge Auditorium

Mechanical $250,000 Electrical 150, 000

The Whittall Music Pavilion

Mechanical $120,000 Electrical 40,000

The Recording Studio

Mechanical $ 40,000 Electrical 40000

Total Construction Budget Cost $640,000

It should be obvious that these budget costs are based upon a limited knowledge of the program and existing budgets, however, they are considered opinion based upon experience with similar spaces in similar cpiality buildings. Further program development and detailed inspection and schematic design should yield more appropriate figures. Also note that these costs are in today’s dollars and do not include contractors contingency or general contractor markups.

F: \PROMO9I P%. 1007

JuU ‘J - 0- 180 FAC DES & cOSTR5dY’5y:XeroxToioCOPiOr 7021 10— 3—97 720AM ; 2022254883’ 202 707 718O$ 2

O!OG C. IZINOUR ASSOCIATES, mo.

Octotr 2, 1 997

Offic. of the AretUtict of di• CapitolW..hlngton D C

FAX 202 225 4683

Att: Mr. Andre Copeland, Pmject Arehltct

St3tement by this Offici Concerning Acoustical Menummints Mada in theCofl1e Auditorium, Jefferson Building, Library of Congress on Sept.mbir291997

Reverberation decay rnesuremenu it 0.250 K , 0.500 ic, i ic a 2 Ic Hertz . utI’izIng art Impulilve energy icuree (calibratid dynamite c.ps) ar• foundto ; idintic.I with thoee which were taken In the same (4) locatIon.pr1r to the pmiint r.itoratbn of th auditorium. The rran decay tImewit1 a full audlince ii I .55 c.

Coi ‘iparlion of the smoothness of the respective decay curves from thoutal Rfl previously vIia-vI those taken presently reaals an improvement.ml , improvement I. du to two factws.(1 ) ElimInitIon of the fized stag. t.anr for the rcttlal me (the teacer,wi’i’ h Ii now movabl instead of bilflQ fixed will now be employed in th.Ipl ich mode only)..

(2) the coflWxing of the surfaces of the former concave mirfaces withintt’ie rear wall pan.le and which surfaces were also reaporielbie for a focusof ate arriving •nargy within the Stage chili has been elimlnaiid.

Th room acoutIS Objectives of the rstorltion have been achieved andtt Collidge will now resume Its •iwiad position among th few greatred ii halls of the world.

Pies ectfully submItted, George C, znöW CoriØultant of Record

IS PLYIW POW4? ROAD • S?0P4Y CEE. cONNeC?ICUT oeao • PWONI: 20$41t.W4

/?i

UNITED STATES GOVERNMENT

MEMORANDUll L.

OJ— LIBRARY OF CONGRESS

APR 4

TO : Scott Fulmore, Chief DATE: March 3 1 , 1995 C&L b.., VIA : David Francis, ChiefM(

M/BIRS Division

FROM Allan McConnell, Acting Assistant Chief MIBIRS Division

SUBJECT: Background & Status Statement - Coolidge Auditorium Project

The Music Division looks forward to the reopening of the world renowned Coolidge Auditorium of the Jefferson Building. Renovation of the Coolidge has required it to be closed for a considerable span oftime with the current target reopening date scheduled for the Fall of 1997. The Recording Lab’s function there will be to record for LC collections and to assist in the broadcast of live events from the auditorium. The music concerts are mixed in the backstage area and recorded in the Jefferson Building Recording Lab. We need to resume operation in the Jefferson Recording Lab as soon as feasible. This should ideally be well ahead of the Coolidge Auditorium’s reopening so that we can install and calibrate it before interconnecting with the auditorium. The successful reopening of this combined facility will require careful coordination of many technical parameters including:

expert specialized knowledge of the dynamic room acoustics as it is affected by construction materials, wall/floor coverings, and ceiling composition & shape, audio isolation & noise abetment, sound amplificatio&reinforcement for the live audience, auditorium sound equalization, feedback suppression, audio micing techniques, remotely controlled microphone positioning, audio mixing & recording in both digital & analogue formats, transmission for broadcast, audio foldback stage monitoring, programmable/preset stage light dimming, remote controlledlrobotic stage lighting, programmable/event configurable intercom, robotic/manual video camera operation, video stage monitoring, electrical distribution, video/audio distribution/monitoring, and video/film projection.

The Lab is not sufficient staffed to properly design and coordinate the installationof these complex systems in addition to the other functions which are required. I recommend thata technical coordinator be hired to design the integrated systems which are required.

I had previously encountered only one vendor which could deal with this level ofcomplexity and which also had a proven track record of successful installations and satisfiedcustomers. This was the Sony Systems Integration Division which specializes in systems designand custom turnkey installations.