HC Barcol-Air - Air Distribution and ControlsP.O. Box 283, 1440 AG Purmerend, the NetherlandsT +31 (299) 689 300 F +31 (299) 436 932 I www.barcol-air.nl E info@barcol-air.nl HC Barcol-Air is part of

Single duct VAV guide specifi cations

1) General

a. VAV boxes shall be provided for areas as indicated on the tender drawings and equipment schedule. The throttling range shall be from 100% - 40%.

b. VAV boxes shall be of the circular or rectangular type, pressure- independent, double-wall units designed for accurate measure- ment and control of air volumes.

c. VAV boxes shall provide suffi cient air movement necessary to maintain occupant comfort even at low turn-down ratio.

d. VAV boxes shall be supplied complete with controllers and/or actuators and temperature sensors and shall be suitable for stand-alone operation upon delivery to site, with provision for connection to the BMS system.

e. VAV controllers and/or actuators and sensor shall be supplied by the same VAV manufacturer to ensure single source responsibi- lity for the performance of the induction VAV.

2) Construction

a. VAV casing shall be air-tight construction made of galvanized steel not less than 0.7mm (22 gauge) thick with only one longitudinal lock form seams, circular inlet and outlet.

b. VAV casing leakage shall be rated to Class II, VDI 3803 / EIN 24 194 or equivalent.

c. Units shall be constructed of double-wall, sandwiched in-between with 25 mm thick, 32 Kg/m3 density thermal & acoustic insulation material. There shall be no insulation material exposed to the moving air stream which will result in poor indoor air quality.

d. VAV boxes shall be of the shut-off type. The damper shall be constructed of the heavy gage metal `Sandwich construction` with peripheral gasket and air leakage through the damper shall be less than 2% at an inlet static pressure of 750Pa of nominal air fl ow.

e. The damper shaft shall be made of Ø12 mm aluminum and rotating in self-lubricating, permanently impregnated nylon bearings. Damper position indicator shall be provided on damper shaft.

f. Inlet and outlet spigots shall be suitable for duct sleeve connection suitable for DIN 24 145 or DIN 24 146 respectively.

g. Each VAV box assembly shall come complete with a metal enclosure box with removable cover (NEMA-1), to house the transformers, controllers/actuators which must be factory-fi tted prior to delivery.

h. In case of Electrical Reheat distribution plenum shall be provided with internally insulated Basotect insulation material.

3) VAV Operation & Performance

a. VAV boxes shall be pressure-independent and capable of resetting the air volume to within 5% of the required air fl ow as determined by the temperature controller, regardless of changes in system air pressure

b. The airfl ow shall be measured at the inlet of the VAV units with a Flo-Cross®, multiple-point averaging chamber and signal amplifying high accuracy air fl ow sensor.c. The airfl ow sensor signal amplifi cation shall be at least 2.5 times for accurate fl ow measurement. Airfl ow sensors shall have a minimum of 24 (2 x 12) test points and provide constant amplifi cation across the full measurement range.

d. The accuracy of the fl ow measurement shall be better than 2.5% at an inlet velocity of 2.0 m/s or higher, even with irregular duct approach.

e. There shall only be one (1) calibration point required for the full range of airfl ow measurement and the accuracy shall be maintained throughout the full airfl ow range.

f. When the room temperature sensor sensed a change in space temperature, it will transmit a reset signal to the controller, which will compare the reset signal with the signal received from the air fl ow sensor, and regulate the volume damper to maintain the right amount of air to the space to maintain room set point temperature.

g. Pressure independent VAV shall come complete with a DDC-VAV controller with built-in direct coupling actuation and self-calibrating fl ow transducer.

h. The DDC-VAV controller shall be LON compatible with Neuron processor or BACnet® type with BTL certifi cation and suitable for integration into the Building Management System (BMS).

i. The complete unit of VAV c/w controller shall be factory-installed and supplied complete by the VAV supplier to ensure one source responsibility for the performance of the VAV. Factory performance test of both the VAV and controller shall be submitted for approval.

j. The integral damper actuator shall be minimum 6-Nm torque, over the shaft mounting type. Stroke shall be fully adjustable from 0-90 degree rotation with visible position indicator. Actuator shall be equipped with manual position override. The actuator stroke time shall be between 95 seconds to 3.6 minutes for 90 degrees rotation at 50Hz operation.

k. Room temperature sensor/thermostat shall come with LCD display and set point adjustment buttons for the user to change the set point. It shall also come with an overriding function to provide air-conditioning outside offi ce hours.

l. Integral step down transformer (240-24VAC, 20VA) shall be provided for each VAV to provide proper power supply for the controller.

m. The pressure drop across the VAV at the fully-opened position shall not exceed 40 Pa.

Single duct VAV guide specifi cations

HC Barcol-Air - Air Distribution and ControlsP.O. Box 283, 1440 AG Purmerend, the NetherlandsT +31 (299) 689 300 F +31 (299) 436 932 I www.barcol-air.nl E info@barcol-air.nl HC Barcol-Air is part of

4) Acoustic Performance

a. VAV boxes sound performance data shall be determined in a reverberation room at an independent sound laboratory according to ISO 3741 and ISO 5135 standards.

b. Performance of units shall be rated to ARI Standard 880-08 and Addendum for Variable Air Volume Terminal Units.

c. The unit design and selection shall give adequate considerations to ensure that noise levels within the space do not exceed NC35 with an inlet pressure of 125 Pa.

5) VAV Installation

a. The VAV boxes shall be adequately supported by means of anchor bolts, rods and angle-bars. The suspension system shall be capable of withstanding the weight of the induction VAV’s as indicated on the drawings/specifi cations.

b. A minimum length of one time the diameter / diagonal straight duct connection shall be used before the inlet of the VAV to achieve an accuracy of the fl ow measurement better than 2.5%.