Air extractors with single or double sandwich panelling in polyurethane foam of thickness 25 mm, designed for installation in false ceilings or in duty rooms. Air deliveries from 1.000 to 15.000 m3/h.
The air extractors or fan sections series ESA T are available in 4 sizes with air volumes from 1000 m3/h to 15.000 m3/h. The maximum duty temperature is 60 °C.
These extractors are manufactured with bearing framework and sandwich paneling. The frame is made of extruded anticorodal aluminium alloy profiles, usually of type AlMgSi 0,5- UNI 9006/1 of dimensions 37 x 25 mm for all sizes, using 3-way corners made of nylon weighted with fiber glass.
The standard paneling is double skin sandwich type made of galvanized sheet, with insulation polyurethane foam of minimum density 40 kg/m3, actual thickness 25 mm for all sizes proposed. The panels are made as follows: – INSIDE SKIN: hot dipped galvanized sheet (galvanization not less than 140 g/m2), 6/10 mm thick – INSULATION: rigid polyurethane foam minimum density 40 kg/m3, thermal conductivity 0.018 ÷ 0.023 W/m°C – OUTSIDE SKIN: hot dipped galvanized sheet, prepainted, 6/10 mm of color Write/Grey. The physical characteristics of the panel are the following: – thermal transmittance factor: 0.91÷ 0.99 W/m2 °C – fire reaction class 1 The fastening of panels on the bearing structure is made by aluminium strips. The gasket between panel and profile for air tightness is made of adhesive neoprene.
The fan-motor set can be easily inspected through an access door fastened to the frame by hinges and handles made of nylon weighted with fiberglass, assuring an easy opening and tightness reliability. The access to fan section is usually equipped with the following safety devices:
Standard units series ESA T are supplied with back panel completely closed on air side.
The extraction units that have to be installed outside or anyway exposed to weathering are supplied with covering roof, as accessory element. The roof is made of flat hot dipped galvanized sheet. On these units the roof is supplied already mounted and fastened to the casing.
For the units series ESA T are supplied with feet H 100 mm.
For each extraction unit series ESA T the fan unit is composed by a definite size of fan and motor, whose choice permits a low noise level and complies with the air volume and pressure required. Each section is equipped with: – motor and fan support – fan – electric motor – transmission – safety devices – accessory elements.
Each fan-motor set is placed on a “cradle“ made of galvanized steel profiles suitably shaped, thickness 20/10 mm. The insulation of the structure is made by rubber shockabsorbers, whose dimensions and rubber hardness are variable according to the size of fan-motor set. A flexible element is always foreseen on fan outlet.
Standard fans are double inlet centrifugal type with square outlet, manufactured with galvanized steel sheet scroll and long life (minimum 20.000 hours in normal working conditions) ball bearings. They are used with forward curved blades impeller, statically and dynamically balanced.
The electric motors used have the following features: – complying with CEI-UNEL regulations and IEC international regulations – closed construction and external ventilation – squirrel cage rotor – three-phase asynchronous with winding: – 230/400 V 50 Hz Eurotension up to capacity of 4 kW included – 400/690 V 50 Hz Eurotension for bigger capacities – single polarity (usually 4 poles) or, unless different request: – 2 poles for fans with rotation frequency higher than 2.800 Rpm – 6 poles for fans with rotation frequency lower than 500 Rpm – B3 shape – horizontal shaft application – class F – IP 55 insulation
The coupling between motor and fan is made by belts and pulleys. Usually pulleys are made of cast iron with trapezoidal races. The number of races, and so of belts, depends on the power to transmit. The manufacturing typologies usually considered are the following: – 1 race: for motor capacities up to 3 kw – 2 races: for motor capacities from 4 kw to 7.5 kw Belt tension can be adjusted by the belt stretcher slide on which the motor is installed.The pulleys used are statically and dynamically balanced and are all supplied with “Taper-Lock” conical bush assuring an easy shaft removal in case of replacement.