July 22, 1994

Contract \# TW0592

**SPECIAL SPECIFICATION**

**SECTION 15490**

**[SPACE PRESSURIZATION CONTROLS]{.underline}**

**[Page]{.underline}**

**[PART 1 - GENERAL]{.underline}**

1.01 Description. 2

1.02 Related Work.. 2

1.03 Quality Assurance.. 2

1.04 References. 3

1.05 Submittals. 3

1.06 Delivery, Storage, and Handling. 3

1.07 Warranty.. 3

**[PART 2 - PRODUCTS]{.underline}**

2.01 Acceptable Manufacturers 4

2.02 System Performance Requirements. 4

2.03 Equipment. 5

**[PART 3 - EXECUTION]{.underline}**

3.01 Inspection. 9

3.02 Preparation. 9

3.03 Installation/Application/Erection.. 9

3.04 Field Quality Control. 10

3.05 Commissioning. 10

**SPECIAL SPECIFICATION**

**SECTION 15490**

**[SPACE PRESSURIZATION CONTROLS]{.underline}**

**[PART 1 - GENERAL]{.underline}**

**1.01 [DESCRIPTION]{.underline}**

> A. A laboratory airflow control system shall be furnished and
> installed to control the airflow into and out of pressure zones. The
> exhaust volume of a laboratory fume hood shall be precisely controlled
> by a velocity controller to maintain a constant average face velocity
> into the fume hood based on actual hood usage. The laboratory control
> unit shall vary the amount of air into the room to maintain
> temperature control, minimum ventilation, airflow balance, and
> laboratory pressurization in relation to adjacent spaces (positive or
> negative).

**1.02 [RELATED WORK]{.underline}**

> A. Section 01300
>
> B. Section 15010
>
> C. Section 15901-S
>
> D. Section 15994-S
>
> E. Section 15995
>
> F. Control Drawings 1046J8C6, & C8.\*\*

**1.03 [QUALITY ASSURANCE]{.underline}**

> A. Manufacturer\'s Qualifications: Firm experienced in manufacturing
> and installing laboratory air flow control system similar to the one
> indicated for this project and that has a record of successful
> in-service performance.

**1.04 [REFERENCES]{.underline}**

> A. Underwriter\'s Laboratories (UL).
>
> B. National Fire Protection Association (NFPA) 70, National Electric
> Code.
>
> C. National Electrical Manufacturers Association (NEMA).

**1.05 [SUBMITTALS]{.underline}**

> A. Make submittals according to this Section, Section 15010, and
> Section 01300.
>
> B. Submit product data including controllers, valves, power supplies,
> and sensors, weights (shipping, installed, and operating), furnished
> specialties, and accessories. Include start-up instruction.
>
> C. Submit shop drawings showing layout and connection for external
> wiring and ductwork connection for each pressure zone.
>
> D. Submit wiring diagrams detailing wiring for power, signal, and
> control systems differentiating between manufacturer-installed wiring
> and field-installed wiring.
>
> E. Submit for each type and size specified maintenance data in the
> operating and maintenance manual.

**1.06 [DELIVERY, STORAGE, AND HANDLING]{.underline}**

> A. See Section 15010.

**1.07 [WARRANTY]{.underline}**

> A. Warranty shall commence upon the date of shipment and extend for a
> period of twenty-four months whereupon any defects in materials or
> system performance shall be repaired by the manufacturer at no cost to
> the owner.
>
> B. The manufacturer shall provide to the owner during and after the
> warranty period, at no additional cost, five (5) years of preventative
> maintenance on airflow sensors (e.g., pitot tube, flow cross, air bar,
> hot wire, vortex shredder, etc.) and flow transducer. The laboratory
> controls manufacturer shall remove the airflow sensors quarterly
> during the five year period to inspect and clean them as to prevent
> inaccuracies due to long term build-up from corrosion, lab tissues,
> wet or sticky particles, or other materials that foul the sensor. The
> transducer shall be checked and recalibrated to insure long term
> accuracy.

**[PART 2 - PRODUCTS]{.underline}**

**2.01 [ACCEPTABLE MANUFACTURERS]{.underline}**

> A. Phoenix Controls
>
> B. Landis and GYR Powers, Inc.

**2.02 [SYSTEM PERFORMANCE REQUIREMENTS]{.underline}**

> A. The laboratory airflow control system shall be fully stand-alone
> for each individual pressure zone. The system shall not use or rely on
> information from controllers in other areas to control the functions
> within its pressure zone.
>
> B. The laboratory airflow control system shall employ individual
> velocity controllers that directly measure the area of the fume hood
> sash opening and proportionally control the hood\'s exhaust airflow in
> a variable volume mode to maintain a constant face velocity over a
> minimum range of 20 to 100 percent at full sash opening. Safety and
> energy savings shall be insured through a corresponding minimum change
> in hood exhaust flow of 5 to 1. The value of the hood\'s face velocity
> shall also be automatically switched between in-use and standby levels
> based on operator usage of the hood. Response time shall be less than
> one second with no more than a 5 percent overshoot or undershoot. The
> system shall achieve 90 percent of its commanded volume within one
> second of the sash reaching 90 percent of its final value with a full
> height sash movement of one second.
>
> C. The laboratory airflow control system shall respond and maintain
> specific airflow ([+]{.underline} 5 percent of signal) and stability
> (\< 5 percent over/undershoot) within one second of a change in duct
> static pressure irrespective of the magnitude of pressure and/or flow
> change or quantity of airflow controllers on a manifolded system.
>
> D. The laboratory airflow control system shall also maintain
> inter-system stability within one second of a change in pressure
> and/or flow to eliminate hunting, system oscillations, and crosstalk
> between airflow controllers.
>
> E. The laboratory airflow control system shall use volumetric offset
> control to maintain room pressurization. The system shall respond and
> maintain room pressurization (negative or positive) within one second
> of a change in room/system conditions.
>
> F. The laboratory airflow control system shall employ highly accurate
> airflow controllers ([+]{.underline} 5 percent of signal) with a
> minimum 8 to 1 turndown to insure accurate pressurization at low
> airflows and guarantee the maximum system diversity and energy
> efficiency.

**2.03 [EQUIPMENT]{.underline}**

> A. Velocity Controller: A vertical sash sensor shall be provided to
> measure the height of each vertically moving fume hood sash. A
> horizontal sash sensor shall be provided for each pair of horizontal
> or overlapping sashes that are located on fume hoods. The airflow at
> the fume hood shall vary in a linear manner between two adjustable
> minimum and maximum flow setpoints to maintain a constant face
> velocity throughout this range. A minimum volume shall be set to
> insure flow through the fume hood even with the sash totally closed.
>
> B. A fume hood monitor shall be provided to receive the sash output
> signals and to generate an exhaust airflow control signal for the
> appropriate volume control device in order to provide a constant face
> velocity. Separate visual indication shall be provided at the monitor
> for both the in-use and standby operating modes. Audible and separate
> visual alarms shall be provided for both flow alarm and emergency
> exhaust conditions.
>
> C. Airflow Controller
>
> 1\. The airflow controller shall be of the venturi valve control type.
> The valve shall be manufactured and assembled in the United States.
>
> 2\. The valve shall be pressure independent over a 0.6-inch (in.) to
> 3.0-in. water gage drop across the valve. Integral pressure
> independent assembly shall respond and maintain specific airflow
> within one second of a change in duct static pressure irrespective of
> the magnitude of pressure and/or flow change or quantity of airflow
> controllers on a manifolded system.
>
> 3\. Airflow accuracy shall be [+]{.underline} 5 percent of reading
> (not full scale) over an airflow turndown range of no less than 8
> to 1. No minimum entrance or exit duct diameters shall be required to
> ensure speed of response, accuracy, or pressure independence. Systems
> requiring minimum duct diameters shall be required to furnish and
> install whatever additional ductwork is needed to meet the
> manufacturer\'s published requirements. The cost of this additional
> ductwork, fitting, and engineering shall be included in the lab
> airflow control systems vendor\'s bid.
>
> 4\. The valve shall be constructed as follows:
>
> a\. Supply and general exhaust air assembly shall be constructed of 16
> gauge aluminum. All bearing surfaces shall be made of a composite
> teflon or teflon infused (versus coated) aluminum. The assembly\'s
> shaft, pivot arm, shaft support brackets, and internal mounting
> hardware shall be made of 316 series stainless steel.
>
> b\. Fume hood exhaust assemblies shall have two baked-on coats of a
> corrosion resistant phenolic coating (Heresite P403 or Phenolflex
> 9457). The assembly\'s shaft shall be 316L stainless steel with two
> additional baked-on coats of a corrosion resistant phenolic coating.
> The pivot arm, shaft support brackets, and internal mounting hardware
> shall be made of 316L stainless steel. All bearing surfaces shall be
> made of a composite teflon or teflon infused (versus coated) aluminum.
>
> 5\. A pneumatic actuator shall be factory mounted to the valve. Loss
> of pneumatic supply air shall cause exhaust valves to fail open to the
> maximum scheduled design flow for the project, and supply valves to
> fail to the minimum scheduled design flow. Constant volume valves do
> not require actuator.
>
> 6\. Each airflow control valve shall be factory calibrated to the job
> specific airflows as detailed on the plans and specifications using
> NIST traceable air stations and instrumentation having a combined
> accuracy of at least [+]{.underline} 1 percent of signal over the
> entire range of measurement. Electronic valves shall be further
> calibrated and their accuracy verified to [+]{.underline} 5 percent of
> signal at eight different airflows per valve.
>
> 7\. All airflow valves shall be individually marked with valve
> specific, factory calibration data. As a minimum, it should include:
> valve tag number, serial number, model number, eight point valve
> characterization information (electronic valves), and quality control
> inspection numbers. All information shall be stored on computer
> diskette in ASCII format for future retrieval or for hard copy
> printout to be included with as-built documentation.
>
> D. Exhaust and Supply Airflow Controller
>
> 1\. The controller shall use electronic-based, closed loop control to
> linearly regulate air volume, proportional to a 0 to 10 Volt (V)
> electronic control signal. The valve shall generate a linear 0 to 10 V
> feedback signal, proportional to its airflow for internal volume
> control, DDC monitoring, or airflow tracking control.
>
> E. Constant Volume Valve
>
> 1\. The valve shall maintain a constant, manually adjustable, volume
> setpoint. It shall be factory calibrated and set for desired airflow
> rate. It shall also be capable of field adjustment for future changes
> of desired airflow rate. Constant volume valves requiring feedback
> shall generate a linear 0 to 10 V feedback signal, proportional to its
> airflow for DDC monitoring or airflow tracking control.
>
> F. Laboratory Control Unit
>
> 1\. A laboratory control unit shall be supplied to control the airflow
> balance of the laboratory room. As a minimum, provide one complete,
> stand-alone laboratory control unit per pressure zone.
>
> 2\. The control unit shall be of electronic design with analog signal
> inputs and outputs. The input shall accept signals proportional to
> fume hood and supply flows. The output signals shall linearly control
> supply valves and general exhaust/return air valves with signals,
> proportional to the desired supply or exhaust volumes.
>
> 3\. The control unit shall maintain a constant, adjustable offset
> between the sum of the pressure zone\'s total exhaust and the
> make-up/supply air volumes. This offset shall be independent of the
> exhaust volume magnitude and represent the volume of air that will
> enter (or exit) the zone from the corridor or other room.
>
> 4\. The control unit shall generate linear analog signals,
> proportional to all airflow sources, sash sensors, and flow alarms.
> The signals shall be available for hard wired connection to the
> facility\'s direct digital control (DDC) system, or through an
> integrated control unit that interfaces directly into the facility\'s
> DDC system. As a minimum, the following signals (points), shall be
> available:
>
> a\. fume hood exhaust flow
>
> b\. fume hood exhaust low flow alarm
>
> c\. fume hood sash position
>
> d\. fume hood usage status
>
> e\. supply/make-up airflow
>
> f\. general exhaust flow
>
> g\. total lab exhaust flow
>
> h\. total lab supply flow
>
> i\. room offset
>
> 5\. The control unit shall also accept direct input signals from the
> facility\'s DDC system or permit operation to be carried out by an
> integrated DDC control unit. As a minimum, the following inputs shall
> be available:
>
> a\. emergency exhaust override
>
> b\. remote room offset adjustment
>
> c\. electronic temperature override
>
> 6\. All points, whether hard wired or totally integrated via one DDC
> laboratory control unit, shall be stored in their respective DDC
> system for trending, archiving, graphics, alarm notification, and
> status reports. Laboratory system performance (speed, stability, and
> accuracy) shall be guaranteed regardless of the quantity of points
> being monitored, processed, or controlled. Multiple laboratory control
> units shall be provided to insure at all times the performance of the
> laboratory is being maintained.
>
> 7\. An integral or wall-mounted power supply shall be included to
> power the complete laboratory airflow control system from one
> dedicated 120 V alternating current (a.c.) line connection.

**[PART 3 - EXECUTION]{.underline}**

**3.01 [INSPECTION]{.underline}**

> A. Inspect areas and conditions, with Installer present, for
> compliance with requirements for installation tolerances, and other
> conditions affection performance of the system.
>
> B. Inspect rough-in for pneumatic tubing and electrical to verify
> actual locations of connections prior to installation.
>
> C. Do not proceed until unsatisfactory conditions have been corrected.

**3.02 [PREPARATION]{.underline}**

> A. Confirm installation of the ductwork prior to installing.

**3.03 [INSTALLATION/APPLICATION/ERECTION]{.underline}**

> A. The laboratory airflow controls (LAC) Contractor shall install the
> sash sensors, interface boxes, and the monitor on the fume hood.
> Vertical sash sensors and their stainless steel cables shall be hidden
> from view. Horizontal sash sensors bars shall be affixed to the
> individual sash panels. Sash interface boxes with interface cards
> shall be mounted within an accessible location.
>
> B. The LAC Contractor shall install the laboratory control unit (if
> panel mounted) and wall-mounted power supply (as required) in an
> accessible location within the indicated pressure zone. The Electrical
> Contractor shall wire a dedicated, single phase 120 V a.c. power
> circuit to the laboratory control unit or wall-mounted power supply.
>
> C. The LAC Contractor shall install 20 pounds-per-square-inch-gage
> clean, pneumatic supply to all airflow control valves.
>
> D. The LAC Contractor shall terminate and connect all cables and route
> all conduit as required. All cable, connectors, conduit, and junction
> boxes shall be furnished by the LAC Contractor.
>
> E. All reheat coils, transitions, and insulations shall be furnished
> an installed by the Mechanical Contractor.
>
> F. Electrical Connections: The following requirements apply:
>
> 1\. Electrical power wiring and conduit requirements are specified in
> Division 16.
>
> 2\. Grounding: Connect unit components to ground in accordance with
> the National Electrical Code.

**3.04 [FIELD QUALITY CONTROL]{.underline}**

> A. Provide a factory-authorized service representative to perform the
> following:
>
> 1\. Inspect the field assembly of components and installation.
>
> 2\. Prepare a written report on findings and recommended corrective
> actions.

**3.05 [COMMISSIONING]{.underline}**

> A. System start-up shall be provided by a factory authorized
> representative of the laboratory airflow controls manufacturer. Said
> start-up shall include setting of the fume hood face velocity and
> electronic verification of supply, make-up, general exhaust, and
> return airflows. The LAC contractor shall be responsible for final
> verification and reporting of all airflows.
>
> B. Provide labor, material, equipment, etc., required to facilitate
> the commissioning process. Perform form tests and verification
> procedures required by the commissioning process when requested by the
> Commissioning Authority and directed by the General Contractor. See
> Section 15995.
>
> END OF SECTION