FCU
Every model of Fan coil units offered shall have been tested and rated in sound and performance in accordance with ARI 443.70 and ARI 143.66 or equivalent. The certified ratings shall be submitted for approval. Samples, one of each model, shall be submitted for approval.
Basic Air Conditioning Units
The horizontal basic unit includes chilled water, cooling coil / heating coil, controls, main drain pan, auxiliary drain pan, fan board, industrial fan(s), fan housing(s), motor filter and thermal insulation.
The vertical basic unit includes chassis of galvanized steel, coil, removable fan boards/main drain pan assembly, auxiliary drain pan, fan(s), fan housing(s), motor and filter.
The main drain pan located under the coil shall have sufficient slope for positive and efficient drainage of condensate under all air conditioning conditions. A secondary drain pan shall be located under the position provided for mounting the control valve. The pans shall be of 1.2 mm (minimum) galvanized sheet steel and adequately insulated with fire retardant thermal insulation.
The chilled water cooling coil shall be of aluminium fins mechanically bonded to seamless copper tubes and tested with compressed air up to 2500 kPa under water.
Units shall be internally insulated with minimum 15mm, 32 kg/m3. density thermal and acoustic insulation.
For exposed mounting the unit shall include a decorative enclosure or cabinet of 1 mm and 1.2 mm thick sheet steel construction for horizontal unit and vertical unit respectively. Internal the cabinet shall be lined with heavy-density thermal and acoustic insulation. The cabinet shall have baked enamel finish. Discharge grilles shall be adjustable quadrifuser grilles of cast aluminium or self-extinguisher high strength plastic.
Furred-in Mounting
For furred-in mounting the air supply register shall be of anodized aluminium construction.
The return air grille shall be of 1 mm thick sheet steel construction, cleaned, bonderised and baked enamel finish.
The return air grille shall be of hinged type and sizes are as follows:-
Air Volume
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Grille Size
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Up to 200 l/s (720cmh)
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600 mm x 600 mm
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250 to 400 l/s (900 – 1440cmh)
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900 mm x 600 mm
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450 to 600 l/s (1620 – 2160cmh)
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1250 mm x 600 mm
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The return air grille shall serve as the regular service access to the fan coil unit, the construction and mounting of which shall be given full consideration of the dual functions.
Fan & Motor
The fan shall be centrifugal fans, forward-curved, double width, double inlet type. The fan wheel shall be of aluminium construction and of small diameter.
The motor shall be of permanent split capacitor (PSC) type, unless otherwise specified in the schedule. The motor shall be designed for 240 volt, 50 Hz electric supply unless otherwise specified. The motor shall be internally protected from overheating and shall operate satisfactorily at 10% over voltage and 15% under voltage at all speed settings.
The fan motor shall be isolated from the main industrial blowers section of the fan coil unit with thermal and vibration isolators.
Each motor shall have easily detract able motor cord with quick disconnect plug, easily accessible.
Control
The fan coil unit, unless otherwise shown on the drawings, shall be provided with a “3- speed/fan on/off” selector switch and a 2-way or 3-way motorized valve as specified.
Controller
The controller shall have a single stage output capable of controlling heating or cooling. The controller shall be complete with a temperature sensor and adjustment in the range of 10 to 40 deg.C. The proportional band shall be adjustable.
Actuators
The actuator shall comprise a split phase capacitor type motor which will transmit power to a linear drive output spindle through a gearbox. Spindle stroke shall be factory set to suit the stroke of the control valves.
Control Valves
The control valve construction shall be not brass pressings-rated to a maximum internal pressure of 17.2 bar (250 1bf/in2) and capable of controlling water at a temperature in the range of 2 to 120 deg.C. All valves will have a minimum stroke between open and close of 100mm (3/8”).
Thermostats
The thermostat shall be of the fully proportioning electronic type with a adjustable throttling range, unless otherwise specified.
Air Filter
The filter medium shall be dry type, washable, self-extinguishing and shall not support combustion. The filter medium shall be able to regenerate at least 10 times by washing.
Based on ASHRAE 52-76 (or AS 1132-R method 4) Gravimetric, the average dust extraction efficiency of the filter medium shall not be less than 70% and the resistant shall not exceed 125 Pa when loaded with dust at 440 gm/m2. At an air velocity of 1.8m/s through the new medium the air resistance shall be less than 15 Pa.