SECTION 15930

AIR TERMINAL UNITS

PART 1 GENERAL

SECTION INCLUDES

Constant volume terminal units.

Variable volume terminal units.

Dual duct terminal units.

Fan powered terminal units.

Variable volume regulators.

Integral sound attenuator.

Integral heating coils.

Integral damper motor operators.

Integral controls.

PRODUCTS FURNISHED BUT NOT INSTALLED UNDER THIS SECTION

Section 15952 - Controls and Instrumentation: Thermostats and control components.

Section 16180 - Equipment Wiring Systems: Thermostats and control components.

PRODUCTS INSTALLED BUT NOT FURNISHED UNDER THIS SECTION

Section [01005 - Administrative Provisions:] [01010 -Summary of Work:] [01011 - Summary of Project:] Owner furnished air terminal units (excess stock).

RELATED SECTIONS

Section 15170 - Motors.

Section 15510 - Hydronic Piping: Connections to heating coils.

Section 15515 - Hydronic Specialties: Connections to heating coils.

Section 15890 - Ductwork.

Section 15910 - Ductwork Accessories.

Section 15936 - Air Outlets and Inlets.

Section 15952 - Controls and Instrumentation.

Section 16180 - Equipment Wiring Systems: Electrical supply to units.

REFERENCES

NFPA 90A - Installation of Air Conditioning and Ventilation Systems.

UL 181 - Factory-Made Air Ducts and Connectors.

ADC 1062 - Air Distribution and Control Device Test Code.

SUBMITTALS

Submit shop drawings under provisions of Section [01300.] [01340.]

Submit shop drawings indicating configuration, general assembly, and materials used in fabrication.

Submit product data under provisions of Section [01300.] [01340.]

Submit product data indicating configuration, general assembly, and materials used in fabrication. Include catalog performance ratings which indicate air flow, static pressure, and NC designation.

Include schedules listing discharge and radiated sound power level for each of second through sixth octave bands at inlet static pressures of one to 4 inch wg (250 to 1000 Pa).

Submit manufacturer's installation instructions under provisions of Section [01300.] [01340.]

OPERATION AND MAINTENANCE DATA

Submit operation and maintenance data under provisions of Section [01700.] [01730.]

Include manufacturer's descriptive literature, operating instructions, maintenance and repair data, and parts lists.

Include directions for resetting constant volume regulators.

QUALIFICATIONS

Manufacturer: Company specializing in manufacturing the products specified in this Section with minimum [three] [eight] [_____] years [documented] experience.

MOCKUP

Provide mockup of typical [exterior] building module under provisions of Section [01400.] [01405.]

If acceptable, mockup will demonstrate minimum standard for the Work. Mockup may [not] remain as part of the Work.

WARRANTY

Provide [five] [_____] year [manufacturer's] warranty under provisions of Section [01700.] [01740.]

Warranty: Include coverage of [system powered control systems.] [operating controls.] [electric motors.]

EXTRA MATERIALS

Provide [two] [_____] additional electric motors of each size under provisions of Section [01700.] [01750.]

PART 2 PRODUCTS

MANUFACTURERS

[___________________________] Model [__________.]

[___________________________] Model [__________.]

[___________________________] Model [__________.]

Substitutions: Under provisions of Section [01600.] [01630.]

MANUFACTURED UNITS

Ceiling mounted [constant] [variable air volume] [fan powered] supply air control terminals for connection to [single] [dual] [low] [medium] [high] pressure duct, central air systems, with [mechanical] [pneumatic] [system powered] [no] constant volume control, [pneumatic,] [electric,] [system powered,] [variable volume controls,] [electric.] [hot water.] [heating coils.]

Identify each airflow unit with clearly marked identification label and airflow indicator. Label shall include unit nominal air flow, maximum factory set air flow, minimum factory set air flow, and coil type.

FABRICATION

Casings: Minimum [20] [22] [_____] gage ([0.9] [0.8] [_____] mm) galvanized steel.

Lining: Minimum [1/2] [one] inch ([13] [25] mm)] thick neoprene or vinyl coated fibrous glass insulation, 1.5 lb/cu ft (24 g/L) density, meeting NFPA 90A requirements and UL 181 erosion requirements. Line attenuator sections with 2 inch (50 mm) thick insulation. [Line insulation with [_____] mil ([_____] mm) mylar film.]

Assembly: Air volume damper, fans, and controls in single cabinet.

Plenum Air Inlets: [Round/oval stub connections] [S and drive connections] for duct attachment.

Plenum Air Outlets: S and drive connections[.] [and blower discharge with one inch (25 mm) flange duct attachment.]

Mixing Sections: Multiple deflection baffles designed for mixing air with minimum pressure loss.

Air Distribution Manifold (Octopus): Factory install where indicated, with [6] [8] inch ([150] [200] mm) diameter collars, each with butterfly balancing damper with lock.

VOLUME DAMPER

Locate air volume damper [and automatic flow control] assembly inside unit casing. Construct from extruded aluminum or 20 gage (0.9 mm) galvanized steel components. Key damper blades into shaft with nylon fitted pivot points.

Automatic flow control assembly shall combine spring rates matched for each volume regulator size with machined dashpot for stable operation.

Mount manually operated damper quadrant or automatic damper operator, and automatic flow control assembly externally[.] [or provide access doors.]

Air volume control damper shall be factory calibrated assembly consisting of damper and damper shaft extension for connection to externally mounted control actuator.

Externally mounted [pneumatic] [electric] actuator shall position damper [normally open] [normally closed] as indicated.

Provide self-contained system-air powered bellows section

consisting of polypropylene bellows [with closed cell neoprene rubber mat to seal against felt edged metal opening.] [actuating pivot drive plate mechanically linked to extruded aluminum damper, with nylon fitted pivot points.] Polypropylene material shall perform at temperatures of 0 to 140 degrees F (-18 to 60 degrees C) and be impervious to moisture and fungus. Design bellows for 10 inches (2.5 kPa) static pressure and factory check for leaks.

HEATING COILS

Hot Water Heating Coil: 1/2 inch (13 mm) copper tube mechanically expanded into aluminum plate fins, leak tested under water to 200 psig (1 380 kPa) pressure, factory installed.

Capacity: Based on [195] [_____] degree F ([90.5] [_____] degree C) entering water, [165] [_____] degree F ([74] [_____] degree C) leaving water and [50] [_____] percent total air volume.

Electric Heating Coil: Slip-in type, open coil design, factory wired and installed, and equipped with primary and secondary over-temperature protection, integral control box with built-in [magnetic] [mercury] contactors, minimum airflow switches, pneumatic/electric switches and relays, UL listed.

FAN ASSEMBLY

Forward curved centrifugal type fan with direct drive permanent split capacitor type, thermally protected motor. [Refer to Section 15170.]

Provide infinitely adjustable speed control with electric/pneumatic and electronic controls.

Internally suspend and isolate fan/motor assembly from casing on rubber isolators.

WIRING

Factory mount and wire controls.	Mount electrical components in control box with removable cover. Incorporate single point electrical connection to power source.

Factory mount transformer for control voltage on electric and electronic control units. Provide terminal strip in control box for field wiring of thermostat and power source.

Factory wire fan to terminal strip.

Provide [fused] [unfused] disconnect.

CONTROLS

Automatic Damper Operator:

Operate: Air volume damper[,][.] [induction damper][,][.] [and automatic volume control.]

Electric Actuator: 24 volt[.] [with high limit.] [with remote temperature read and reset capability.]

Pneumatic Damper Operator: [8-13] [3-13] [_____] psig ([55-90] [21-90] [_____] kPa) spring range.

Maximum Volume Controller and Probe: Pneumatic, with calibration pressure taps for high flow limited proportional variable air volume control.

Velocity Reset Controller and Probe: Pneumatic, with calibration pressure taps for pressure independent proportional variable air volume control with means for pressure independent compensating for varying inlet static pressure, with minimum and maximum limits set at reset device, mounted in control box.

Thermostat: [Wall-mounted pneumatic] [Diffuser-mounted pneumatic] [Wall-mounted electric] type with appropriate mounting hardware.

System Powered Controls:

Suitable for operation with duct pressures between 0.25 and 3.0 inches (60 and 750 Pa) static pressure.

Factory mounted and piped 5 micron filter, velocity resetting adjustable high limit control and amplifying relay.

Aspiring [diffuser] [wall] mounted thermostats.

Mount controls in sheet metal enclosure on unit.

Provide morning warmup control to sense duct temperature and control unit at maximum airflow during heating mode.

Auxiliary Pneumatic Controls:

Damper actuators for warm and cold inlet. Modulate cold damper closed as warm damper opens. [Provide for dual duct constant volume operation.]

Sequence so warm damper actuator may be field adjusted to start opening simultaneous with closing of cold damper or delayed until up to 10 degrees F (6 degrees change in room temperature after cold damper has

closed.

Sequence pneumatic operators with spring ranges selected so warm damper begins to open after cooling damper has fully closed. Cooling damper to be normally [closed.] [open.] [Provide pneumatic pressure independent controls [or high limit controls] for control of both warm and cold damper, factory calibrated for maximum air flow.]

FAN POWERED UNIT CONTROLS

[Pneumatic] [Electric] [Electronic] Controls: Contain in NEMA-1 enclosure with access panel sealed from air flow and mounted on side of unit. Factory mount controls [and thermostat] to accomplish the following sspecified sequence of operation.

Electronic Control, Central System Fan "On" - Occupied Mode:

When duct pressure is sensed indicating primary air system operating, thermostat and primary variable volume damper proportions air flow from central system.

As thermostat senses reduced cooling demand, volume damper closes. At field adjustable point, unit fan is energized. [As cooling demand continues to fall, volume damper closes and fan speed increases.]

If central duct system pressure varies, volume damper maintains constant primary air flow.

As thermostat senses no cooling, control system closes volume damper. Before heating is initiated, control enters field adjustable no load band. On sensing need for heat, heating coil is energized [proportionally.] [in steps.]

Electronic Control, Central System Fan "Off" - Unoccupied Mode:

Provide field adjustable temperature setback. On need for heat, terminal unit fan and heating coil are energized.

Hold volume damper closed.

Pneumatic/Electric Control, Central System Fan "On" -Occupied Mode:

As thermostat senses cooling, volume damper proportions air flow from central system.

As thermostat senses less cooling and damper closes, [pneumatic/electric] [damper position] switch energizes fan.

Electronic fan speed control manually adjusts maximum fan speed to match downstream resistance.

Velocity reset primary air control (pressure independent) with maximum and minimum limits.

Hi-limit device, factory set, limits maximum primary air flow.

As thermostat senses no cooling, control system closes volume damper to stop flow from central system primary air duct before heating is initiated. On sensing further need for heat, heating coil is energized.

Pneumatic/Electric Control, Central System Fan "Off" -Unoccupied Mode:

Thermostat cycles fan.

Day/night thermostat cycles fan and controls at

reduced temperature.

TESTS

Provide testing of units under provisions of Section [01400.] [01410.]

Test run [fan/motor combinations,] volume dampers and controls. Check sequence of operation and air flow limits [corrected for project altitude] at factory prior to shipment.

Base performance on tests conducted in accordance with ADC 1062.

Automatic flow controller shall be capable of maintaining air flow to within 5 percent of set point with inlet static pressure variations up to [2] [4] [_____] inches ([0.5] [1.0] [_____] kPa).

Maximum Casing Leakage: 2 percent of design air flow at rated inlet static pressure.

Maximum Damper Leakage: 2 percent of design air flow at [one inch (0.25 kPa)] [rated] [__________] inlet static pressure.

PART 3 EXECUTION

INSTALLATION

Install in accordance with manufacturer's instructions.

Provide ceiling access doors or locate units above easily removable ceiling components.

Support units individually from structure. Do not support from adjacent ductwork.

Connect to ductwork in accordance with Section 15890.

Provide minimum of [5] [_____] ft ([1.5] [_____] m) of [one] [2] inch ([25] [50] mm) thick lined ductwork downstream of units.

Install heating coils in accordance with Section 15790.

ADJUSTING

Reset volume with damper operator attached to assembly allowing flow range modulation from 100 percent of design flow to [0] [50] [__________] percent full flow. [Set units with heating coils for minimum [50] [_____] percent full flow.]

TERMINAL UNIT SCHEDULE

Drawing__Code Location Minimum/Maximum	Minimum	Coil

Airflow Static_Pressure Heat_Output

Drawing_Code	X-1	X-2	X-3

Size

Air Flow Range

Minimum

Maximum

Sound Power dB

@ 1.5 inch (375 kPa)

Static Pressure

Radiated

2nd Octave

3rd Octave

4th Octave

5th Octave

6th Octave

Noise Criterion

Discharge

2nd Octave

3rd Octave

4th Octave

5th Octave

6th Octave

Noise Criterion

Coil at Minimum Air

Heat Output

Entering Air Temp

Air Temp Rise

Number of Rows

Entering Water Temp

Leaving Water Temp

Electric Input

END OF SECTION