Fan - Powered Terminal Unit Series Flow

Transcription

1 5/22/M/1 Fan - Powered Terminal Unit Series Flow Type TFP Trox (Malaysia) Sdn Bhd 20 Persiaran Bunga Tanjung 1 Senawang Land Industrial Park Seremban Negeri Sembilan Darul Khusus Malaysia Telephone Telefax wwwtroxmalcommy trox@troxmalcommy

2 Contents Description Description 2 Constructions Dimensions Materials 3 Aerodynamic Data 6 Technical Data Accessories 8 Nomenclature 9 Quick Selection 10 Electric Heater Data 13 Order Details Velocity Flowgrid Primary Air 2 Fan Motor 3 Controls Package 4 Air Induction Port 5 Access Panel Trox Series Fan VAV Terminal Boxes take primary and induced air and mix the two thoroughly to provide a constant air supply to the occupied zone of the building Total flow from the diffuser is kept substantially constant thus giving very good air distribution even with high turn down of the primary air volume The primary air damper can be fully shut, with 100% recirculated or induced air Trox Series Fan VAV Terminal Boxes have been designed and developed to achieve lower room noise levels Discharge and case radiated sound pressure levels of NC 35 can be achieved in the occupied zone Pressure independent control of the primary VAV damper is accomplished by use of a Multi-point flowgrid which gives accurate control of air flow even with a 90 bend on the inlet spigot Mixing between the primary airstream and the induced warm air from the ceiling void is by a forward curved blade centrifugal fan with direct drive motor This direct drive motor is of the permanent split capacitor type, suitable for use with stepless fan speed controllers Trox Series Fan VAV Terminal Boxes are eminently suitable for low temperature air applications If the supply air temperature is low, then the fan volume flow rate must be higher than the 100% primary air volume flow rate to ensure suitable air temperature at the diffuser Design of the TFP ensures that at 100% primary air, sufficient induced air is mixed with the primary air so that the air discharged has a conventional cooling differential which will not cause draught problems in the space being conditioned 2

3 Construction Dimensions Materials Trox Series Fan VAV Boxes save energy by utilising the warm air in the building already generated by other sources and mixing it with primary air before distributing a constant volume air supply direct to the occupied zone This reduces energy consumption, so providing long term operational savings Available in a range of sizes Trox Series Fan VAV boxes are suitable for pneumatic or electronic control Volume flow tolerance is dependent on the type of control system but is typically ±5% to ±10% of set volume The units are designed for use in VAV systems and in conjunction with DDC controllers permit communications between the boxes and a centralised control area General Series Fan VAV terminal VAV boxes are constructed from galvanised steel All 230 V electrical control components are protected by sheet metal enclosures The enclosure has a single electrical (230 V or 400 V) mains entry position Casing The casing is sturdily constructed of galvanised sheet steel The overall construction is reinforced to meet acoustic performance requirements - Casing with acoustic and thermal insulation, erosion resistant up to 20 m/s - High pressure side with duct spigot suitable for circular ducting - Low pressure side suitable for angle frames - Mounting brackets for support rods are provided on the top of the casing Access Panel To avoid removal of the terminal box once fitted in the system, an access panel is provided in the casing underside so that the fan/motor can be serviced, or in the unlikely event of failure, removed without disturbing the duct connections Type TFP without heater PLAN VIEW 150 Ø10 HOLES IN 4-OFF SUPPORT BRACKETS 150 CONTROLS ENCLOSURE WITH REMOVABLE LID MOUNTED ON DISCHARGE END OF UNIT Ø D PRIMARY AIR SPIGOT INTERNALLY MOUNTED FAN AS SPECIFIED ON ORDER SCHEDULE, SIZED TO SUIT PERFORMANCE REQUIREMENTS S 14 W UNIT BODY WIDTH L UNIT BODY LENGTH DRIVE SIDE VIEW 40 SPIGOT CONNECTION LENGTH VELOCITY FLOW GRID FITTED IN PRIMARY AIR SPIGOT, TUBING TO CONTROLS IS RETAINED WITHIN THE MAIN BODY INDUCTION AIR PORT IN FRONT FACE, MAY BE SUPPLIED FITTED WITH INLET FILTER AS OPTIONAL EXTRA H UNIT BODY HEIGHT F I/S DUCT AIRFLOW DIRECTION VIEW ON DISCHARGE DUCT END E I/S DUCT G 32 Ø10 FIXING HOLES E + 20mm x F + 20mm CENTRES FULL WIDTH TWIN REMOVABLE ACCESS PANELS ON BASE OF UNIT Ø12 DRIVE SPINDLE VELOCITY GRID BARBED ELBOW CONNECTIONS PROTRUDE DRIVE SPINDLE SIDE OF UNIT C VIEW ON INLET SPIGOT END Unit Spigot Size Size L W H C D E F G S

4 Construction Dimensions Materials Insulation - The inside of the terminal box is acoustically lined with 25mm faced insulation - The access panels are also lined with the same material - All lining materials have Class O fire rating conforming to UK building regulations VAV Section Volume Flow The Series Fan VAV Terminal Box is suitable for pressure independent control Volume flow is sensed by a multi-point, averaging flowgrid measuring pressure differential - Primary volume flow tolerance is dependent on type of control system but is typically ±5% to ±10% of set volume - Primary volume flow control range typically 100% to 10% depending on type of control - Pneumatic or electronic controllers can be fitted - Primary air volume flow range adjustment at factory with factors supplied to allow site adjustment - Volume measurement can be made on site using the flowgrid; also adjustment of volume flow through controller - Control and full shut off is achieved with a single damper Pressure Differential Flowgrid - Minimum pressure differential signal from 2Pa upwards - Sensor tubes in aluminium - Test pressure tappings are supplied with tight fitting caps - Calibration graphs and constants are provided to relate volume flow in litres/second to the measured pressure differentials - The differential pressure generated by the averaging sensor is within ±3% of the calibration chart value over the range of typical primary air flow rates Type TFB with Electric Heater PLAN VIEW Ø10 HOLES IN 4-OFF SUPPORT BRACKETS CONTROLS ENCLOSURE WITH REMOVABLE LID MOUNTED ON DISCHARGE END OF UNIT ELECTRIC HEATER ENCLOSURE WITH REMOVABLE LID FOR HEATER ELEMENT ACCESS Ø D PRIMARY AIR SPIGOT 14 W UNIT BODY WIDTH 14 INTERNALLY MOUNTED FAN AS SPECIFIED ON ORDER SCHEDULE, SIZED TO SUIT PERFORMANCE REQUIREMENTS 400 ELECTRIC HEATER DUCT SUPPLIED FITTED 100 L UNIT BODY LENGTH DRIVE SIDE VIEW S 40 SPIGOT CONNECTION LENGTH VELOCITY FLOW GRID FITTED IN PRIMARY AIR SPIGOT, TUBING TO CONTROLS IS RETAINED WITHIN THE MAIN BODY INDUCTION AIR PORT IN FRONT FACE, MAY BE SUPPLIED FITTED WITH INLET FILTER AS OPTIONAL EXTRA H UNIT BODY HEIGHT F I/S DUCT AIRFLOW DIRECTION VIEW ON DISCHARGE DUCT END E I/S DUCT G 32 Ø10 FIXING HOLES E + 20mm x F + 20mm CENTRES FULL WIDTH TWIN REMOVABLE ACCESS PANELS ON BASE OF UNIT Ø12 DRIVE SPINDLE C VELOCITY GRID BARBED ELBOW CONNECTIONS PROTRUDE DRIVE SPINDLE SIDE OF UNIT VIEW ON INLET SPIGOT END Unit Spigot Size Size L W H C D E F G S

5 Construction Dimensions Materials Control Damper The single blade damper is mounted in the circular duct behind the flow measuring grid The drive spindle is extended through the casing and a suitable actuator slips over the shaft and locks directly to it -The closed damper has a shut off leakage at 500Pa inlet pressure of less than 05% of rated flow - The damper blade is positively connected to its drive shaft which runs in maintenance free polyurethane long life bearings - EPDM synthetic rubber damper seal, thermoplastic elastomer compound seal suitable for temperatures up to 50 C Electric Heaters 1) The electric heater is available as an integral unit complete with controls including fuses and interlocks The integral air heater has elements designed for black heat operation and consists of 80/20 nickel chrome wire in a stainless steel tube filled with magnesium oxide An automatic reset high temperature cut out is fitted and a earth stud included The heater is manufactured to British Standards/Codes as applicable and fully factory tested An optional low air pressure switch can be fitted This switch will disconnect the heater if the fan stops The heater elements are wired back into the control enclosure, including the earth, and heater fuses can be supplied Control of the heater can be arranged for stepless control by thyristors Control type should be selected to suit the temperature controller used and the degree of accuracy required on temperature control 1) Typical details are given Electric heaters are available on request Full details required such as kw, Voltage, Phase should be stated 5

6 Aerodynamic Data Primary Air Volume Range Air Damper Leakage Minimum Inlet Static Pressure Performance Details - Discharge flow typically remains constant within ±75% from 100% primary to minimum primary air - Minimum primary air pressure differential required for values see Table 2 Notes The minimum primary air volume shown is the minimum factory set value for control purposes See Table 1 for leakage on full shut off Fan volume is given for a typical downstream pressure of 50 Pa Other downstream pressures duties available on request Table 1: Primary Air Volume Range Air Volume Air Volume Air Leakage V L Spigot 10 m/s duct 2 m/s duct 500 Pa L/s CFM L/s CFM L/s CFM When selecting the size of the primary air spigot, reference should be made to the quick selection details on pages 9 and 10 The minimum air volume controlled by the primary air damper is dependent on the volume controller specified Table 2: Minimum Inlet Static Pressure Unit Inlet V 1 p SI min size spigot CFM l/s inch wg Pa

7 Technical Data Accessories Fan and Motor The Series Fan VAV terminal boxes are fitted with fan casings (Scrolls) manufactured from sheet steel The fans have a forward curved fan impeller All fan motors are direct drive resiliently mounted via location brackets suitable for 230 volts 50 Hz single phase and are supplied with auto reset thermal overloads The fan motors are permanent split capacitor types fitted with permanently lubricated bearings All earthing wiring and component selection conforms to local wiring requirements Fan Motor Speed Control All fan motors fitted to Trox Series Fan VAV Terminal Boxes are suitable for fan speed control Supplied as standard is a manually adjusted solid state Triac based fan speed controller which provides stepless adjustable fan speed from maximum to minimum The system is matched to the motor and includes minimum voltage limits to ensure stable motor operation The control incorporates hard start, ie: maximum voltage for a defined short period to ensure that fan rotation is correct Accessories Provision is made on the induction port of the unit for the installation of air filters These are supplied as throwaway filters Table 3: Fan Motor Details Unit Motor Current Motor Watts Size at 230 V 50 H Z A 1 W Power factor: 09 approx 7

8 Nomenclature Nomenclature NC 1 NC 2 NC 3 NC 4 NC 5 NC 6 : Room NC value calculated from octave sound power levels of ductborne discharge noise with 100% primary air at 100 Pa duct pressure and 50 Pa downstream static pressure (For assumptions see Table 4) : As NC 1 but at 250 Pa duct pressure : As NC 1 but at 500 Pa duct pressure : Room NC value calculated from octave sound power levels of radiated and induction port noise with 100% primary air at 100 Pa duct pressure and 50 Pa downstream static pressure (For assumptions see Table 5) : As NC 4 but at 250 Pa duct pressure : As NC 4 but at 500 Pa duct pressure p SD p SI in Pa: Downstream static pressure in Pa: Inlet static pressure p SI min in Pa: Minimum inlet static pressure V 1 in l/s (CFM) : Primary air volume flow rate V L in l/s (CFM) : Leakage volume flow rate across closed primary air damper W 1 A 1 Q in Watts: Output power of motor in amps: Motor running current (max) in kw: Heat output of electric heater 8

9 Quick Selection Procedure Discharge Quick Selection Procedure Discharge NC Levels The NC values have been calculated using procedures given in ARI Standard 885, with a Downstream static pressure (psd) of 50 Pa (02 inch wg) in all cases The following assumptions have been made for discharge NC values: - Environmental adjustment factor (ARI 885) mm (5ft) of 25mm (1 inch) lined duct - Unlined rectangular tee - Number of outlets as shown in Table 4 below mm (5ft) of 200mm (8 inch) dia lined flexible duct - End reflection of 200mm (8 inch) dia connection - Room effect 142m3 (5000ft3) and 3m (10ft) distance from source Example: Unit size 2 with 2 outlets Centre Frequency Hz k 2k 4k Total reduction sound power to sound pressure level db For further information and explanation of NC value calculations please refer to your nearest Trox Sales Office Table 4: Quick selection Discharge Noise (100% primary air) Discharge Noise Unit Inlet V1 Flow division, p SI number of Size Spigot 100 Pa 250 Pa 500 Pa outlets CFM l/s 1) NC 1 NC 2 NC <20 <20 < <20 <20 < <20 <20 < <20 <20 < <20 <20 < < < <20 <20 < <20 < < <20 < < ) Assumed number of outlets served by fan box for acoustic calculations Selection Method First select unit size on basis of fan volume flow rate from Table 4 or Table 5 From Table 1 select inlet spigot size to meet maximum and minimum primary air requirements as follows: - Review maximum size spigot for unit size selected - If selection not possible take next smaller size spigot - Continue until first suitable spigot size, to suit both maximum and minimum primary air volumes, is found Example: Unit size 2 with 2 outlets Given Fan flow 400 l/s Room noise limit NC38 Maximum Primary Air 380 l/s Minimum Primary Air 105 l/s Selection is Unit size 2 Spigot size 10 9

10 Quick Selection Procedure Radiated Quick Selection Procedure Radiated NC Levels The following assumptions have been made for radiated NC values: - Environmental adjustment factor (ARI 885) Ceiling Void/ceiling tile reduction as follows: Centre Frequency Hz k 2k 4k Reduction db Example: All unit sizes Centre Frequency Hz k 2k 4k Total reduction sound power to sound pressure level db For further information and explanation of NC value calculations please refer to your nearest Trox Sales Office - Room effect 142m3 (5000ft3) and 3m (10ft) distance from source Table 5: Quick Selection Radiated Noise (100% primary air) Radiated Noise Unit Inlet V1 p SI Size Spigot 100 Pa 250 Pa 500 Pa CFM l/s NC 4 NC 5 NC < <20 < <

11 Sound Power Levels Discharge Table 6: Discharge Sound Power Levels Discharge Sound Power Levels Unit Inlet V 1 Fan duty = 100% primary air, p SD = 50 Pa Size Spigot p SI Pa p SI Pa p SI Pa CFM l/s ) Sound power levels are in decibels re wattts 11

12 Sound Power Levels Radiated Table 7: Radiated Sound Power Levels V Radiated sound power levels, including induction port noise Fan duty = 100% primary air, p SI = 50 Pa Unit Size Inlet Spigot 1 p SI Pa p SI Pa p SI Pa CFM l/s ) Sound power levels are in decibels re wattts 12

13 Order Details Specification Text Series Fan VAV boxes type TFP for constant room air supply volume combined with VAV primary air control having high turndown by use of a multi-point flowgrid Induction of warm air from the ceiling void by forward curved blade centrifugal fan with direct drive motor Single blade control damper with seal for shut off Stepless speed controller to enable fan duty to be set to match the downstream duct system pressure Materials Casing manufactured from galvanised sheet steel Internally lined with faced insulation Multi-point flowgrid constructed from aluminium tubes Fan casing manufactured from sheet steel Fan impeller from aluminium alloy or steel according to size Order Example Make : TROX Type : TFP-E-C/2x10/0/BC5/ Order Code - Fan Assisted Terminal Box / / / / / TFP - E - C 2 x 10 0 BC Product Type Version Case Size Control Diagram Refer to Trox Handing L = Left Hand R = Right Hand Reheatiil E* = with electric reheat coil or no entry Filter C = Throwaway or no entry Induction flowgrid S = induction port with flow pressure differential sensor or no entry Spigot Size Always 0 Controller Refer to Trox or no entry Minimum primary air volume l/s Maximum primary air volume l/s Fan volume l/s *Electric Heater details to be given on separate schedule Design changes reserved All rights reserved Trox (UK) Limited (02/2003) 13