FSS TU4 – Product description Sept 2009 1
FSS Fantile TU4 Product description
FSS TU4 – Product description Sept 2009 2
INDEX 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9
Product description ...................................................................................................................................... 3 General .................................................................................................................................................. 3 Casing .................................................................................................................................................... 3 Damper .................................................................................................................................................. 3 Fan section ............................................................................................................................................ 3 Controller ............................................................................................................................................... 4 Electrical connections ............................................................................................................................ 4 Electric heater (optional) ........................................................................................................................ 4 Standards .............................................................................................................................................. 4 Overall dimensions ................................................................................................................................ 5
2
Control functions .......................................................................................................................................... 6
3
Technical data .............................................................................................................................................. 7 3.1 Air flow ................................................................................................................................................... 7 3.2 By pass air flow ...................................................................................................................................... 8 3.3 Noise level in the controlled space ........................................................................................................ 9 3.4 Noise level in free field conditions .......................................................................................................10 3.4.1 General ................................................................................................................................................10 3.4.2 Test method .........................................................................................................................................10 3.4.3 Test results ..........................................................................................................................................10 3.5 Air distribution in the space .................................................................................................................12 3.6 Air velocity in the space .......................................................................................................................13
FSS TU4 – Product description Sept 2009 3
1
Product description
General The FSS TU4 is a patented terminal used as part of the Flexible Space underfloor air conditioning system, which extracts air from below the raised floor and in addition recirculates room air. It has been designed to be installed within a raised floor and may be used as part of the walking surface in the room. The supply and return section are both positioned below two robust grilles, that can be walked on. The FSS TU4 is made up of 4 sections: Casing Damper Fan section Controller and Electrical connection
are 600 x 740 x 215 mm and it occupies the space of only one raised floor tile. The face area of each grille is 215 x 599 mm each; its height can be adjusted according to the flooring with which the TU is to be used, from 30mm to 50mm. Underfloor air enters through one side of the terminal. A raised floor height of at least 220 mm is required, depending on the slab roughness and tolerance).
1.2 Damper The damper is activated (on-off) by an electric motor, which controls its opening to draw underfloor air or closing to allow recirculation of the ambient air. The damper includes a by-pass that permits the FSS-TU4 to draw a certain amount of underfloor fresh air even when it is working in the recirculating mode. When the damper is open the fans draw air from the underfloor void. When the damper is closed, the fans draw room air through the the recirculation grilles and deliver it to the room from the supply section. The by-pass section can be regulated from a minimum to a maximum opening by an adjustable stop.
1.3 Fan section
1.1 Casing The FSS TU4 consists of a structure of steel sheet, finished in black powder coat. It features two separate aluminium grilles, both with straight fins, one grille for the air supply and the other for the recirculation of air from above the floor. The supply grille features a hatch which allows access to the control without the need to remove the grille itself. The overall dimensions of the FSS TU4
The fan section comprises a totally-enclosed electric motor to IP23 standard which drives two centrifugal fans. The electric motor is equipped with in-built thermal protection with automatic reset. One side of the recirculating section contains a compartment which houses the room air temperature sensor. The positioning of this sensor guarantees that it constantly samples ambient air, even when the terminal is supplying air from under the floor. The airflow can be electronically modulated from a minimum to a maximum value.
FSS TU4 – Product description Sept 2009 4
1.4 Controller The controller is of the microprocessor controlled electronic type. It is fitted with two air temperature sensors: the first sensor is used to read the space temperature, the second the underfloor temperature. By comparing these two readings with the chosen set point the FSSTU4 controls the opening or closing of the damper. If the space temperature is higher than the setpoint, and the underfloor air temperature is lower than the setpoint, the damper is closed to its recirculation position, so that the minimum underfloor air is drawn into the room (note that this is adjustable).If the temperature is still too low, the electric heater, if installed , is energised to maintain the requested ambient conditions. The following indication will be available on the LCD display: room temperature, underfloor temperature, setpoint value, fan speed selected, direct or inverse operating mode. The control will perform the functions of : temperature control, fan speed modulation, automatic and independent cooling/heating changeover with possibility of automatic setpoint shift, alarm visualisation, programmable time delay on the electric heater.
1.5 Electrical connections The electric components are housed within a special box within the cabinet. The FSS TU4 is fitted with 4.6 m-long power cable and plug for connection to the 230/1/50 electrical supply. Two models of plug are available: Standard European Shuko plug and Standard British three-pin plug. Alternatively, the Fantile can be supplied without plug.
1.6 Electric heater (optional) FSS TU4 can be fitted with an optional stainless steel electric heater (core and fins) which operates at a very low surface temperature. Three models are available: 250W/230V , 500W/230V and 1000W/230V.
1.7 Standards The unit has been designed according to IEC and CEI standards.
FSS TU4 – Product description Sept 2009 5
1.8 Overall dimensions
FSS TU4 – Product description Sept 2009 6
2
Control functions
See Fatronic E manual
FSS TU4 – Product description Sept 2009 7
3
Technical data
3.1
Air flow
The following diagram shows air flow values at various underfloor static pressures. The underfloor static pressure is relative to the ambient pressure and has been considered up to the nominal maximum value of 20 Pa. It is, however, recommended that the pressure is maintained below 15 Pa, in order to guarantee a correct control of the air flow. The FSS TU4 constantly draws a certain amount of ambient air through a compartment in which the sensor for the room temperature reading is located. This happens even when the damper is in the
recirculating position and the fans are drawing air from under the floor. The sensor positioning guarantees that it is always subject to a stream of room air, and therefore that it senses the correct temperature. In the diagram the Underfloor Air Suction is indicated: it is the air drawn from under the floor. This represents the value to be considered in the thermal design calculation. The air flow can be modulated by the electronic control. The diagram therefore indicates various curves for different fan speeds: each curve refers to the percentage shown on the controller’s display. In the reading of the air flow value it must be considered that in a typical installation the underfloor static pressure in the supply zone is normally between 3 and 10 Pa.
NOTE: Approximately 5% air flow reduction must be considered when the FSS TU4 is fitted with the optional electric heater FSS TU4 Air flow for different fan speeds –220V
Underfloor pressare drop (Pa)
.
FSS TU4 – Product description Sept 2009 8
3.2
By pass air flow
A variable by-pass is fitted on the FSS TU4 which ensures a continuous bleed of the required quantity of fresh air even when the damper is closed. The values in the diagram refer to the air flow through the by-pass. In the reading of the air flow value it must be considered that in a typical installation the underfloor static
pressure in the supply zone is normally between 3 and 10 Pa.
NOTE: Approximately 5% air flow reduction must be considered when the FSS TU4 is fitted with the optional electric heater
Underfloor pressare drop (Pa)
By-pass opening
FSS TU4 – Product description Sept 2009 9
3.3
Noise level in the controlled space
The diagram can be used for a quick assessment of the noise produced by the FSS TU4 when installed in a room with a given sound absorption characteristic. Noise generated by the FSS TU is related almost completely to the fan speed. The underfloor pressure level has a minor effect and becomes negligible at high fan speed. The noise generated can be therefore estimated quite accurately at 0 Pa overpressure working condition (recirculating mode) using the diagram. Measurements have been carried out at 1 metre distance and 1 metre height from the FSS TU4 at 0 Pa underfloor pressure. Sound pressure level is given for 3 values of equivalent absorption surface. As indications only, these correspond to a “standard office” (3 x 4 m – 2,8 m height) with differing furnishing situations:
38 sq.m Sabine, fully furnished standard office 24 sq.m Sabine, partially furnished standard office 12 sq.m Sabine, empty standard office How to use the diagram Enter the air flow diagram with the required discharge air flow and the working underfloor pressure and determine the airflow at 0 Pa (recirculating mode) With this airflow value enter the noise diagram below and determine the sound pressure level in dB(A) corresponding to the given equivalent absorption surface. Example Airflow required: 450 m3/h (H=200 mm) Underfloor pressure: 5 Pa Fully furnished room (38 sq.m) FROM AIR FLOW DIAGRAM Air flow at 0 Pa =380 m3/h FROM NOISE LEVEL DIAGRAM Sound Pressure Level = 36
SPL dB(A)
FSSTU4 Sound Pressare Level Underfloor pressure 0 Pa
3
Underfloor Air suction m /h
dB(A)
FSS TU4 – Product description Sept 2009 10
3.4
Noise level in free field conditions
For each mode four different air flow values have been selected.
3.4.1 General The following table refers to the values of Sound Pressure Level in free field conditions and Sound Pressure Level, measured by an independent laboratory.
3.4.3 Test results The reported values refer to: 1. Noise Pressure Level in dB(A) – Lp: measured on the surface on the semisphere in free field conditions (radius 1,26 m). 2. Noise Power Level in dB(A) – Lw: obtained from the above measurements(reference 1 pw).
3.4.2 Test method The test has been carried out according to ISO 3745- 1977 “Determination of sound power levels of noise sources. Precision methods for anechoic and semi-anechoic rooms”. 10 fixed microphones were used, these being within the area of an hypothetical hemisphere (radius = 1.26 m) around the unit. Measurements have been carried out for three different working modes: Air recirculated above the floor (damper closed) Air taken from underfloor with 0 Pa overpressure
Work Condition Air recirculated from the ambient
Air taken from underfloor with 0 Pa overpressure
Air taken from underfloor with 20 Pa overpressure
Air taken from underfloor at maximum nominal pressure of 20 Pa
Due to the system configuration the numeric value of Lw exceeds the corresponding Lp by 10 units. The Noise Power Level can be used by acoustic experts to determine the actual noise of the FSS-TU4 in the space where the terminal will be installed. A copy of the test is available on request.
Air flow m3/h
Lp dB(A)
Lw dB(A)
260 385 495 545 260 385 495 545 450 555 655 700
23 30 38 41,2 22,5 28,5 36,5 40 28,8 31,5 38 40,8
33 40 48 51,2 32,5 38,5 46,5 50 38,8 41,5 48 50,8
FSS TU4 – Product description Sept 2009 11
INSTALLATION
FSS TU4 – Product description Sept 2009 12
3.5
Air distribution in the space
The following diagrams refer to the air velocity in the space where the FSS TU4 is installed in the following configurations:
Damper closed: air recirculated in the space
Damper open at differing underfloor static pressure: 1. 0 Pa underfloor static pressure (total air flow: 350 m3/h)
2. 10 Pa underfloor static pressure (total air flow: 470 m3/h), the most frequent situation 3. 20 Pa underfloor static pressure (total air flow: 525 m3/h) The values have been measured on 3 planes as indicated. The curves are limits of the zones where the air velocity is higher than 0,5 m/sec and 0,18 m/sec respectively. Diagrams without any curves indicate that the air velocity is lower than 0,18 m/sec at all the points tested.
FSS TU4 – Product description Sept 2009 13
3.6
Air velocity in the space
ROOM AIR SUCTION
PLANE “A”
PLANE “B”
PLANE “C”
FSS TU4 – Product description Sept 2009 14
UNDERFLOOR AIR SUCTION PLANE “A”
0 Pa
10 Pa
20 Pa
0 Pa
10 Pa
20 Pa
0 Pa
10 Pa
PLANE “B”
PLANE “C”
20 Pa
FSS TU4 – Product description Sept 2009 15
Advanced Ergonomic Technologies Ltd The Center 201-203 London Road East Grinstead West Sussex RH19 1HA United Kingdom TEL: + 44 (0)1342 310400 FAX:+ 44 (0)1342 310401 aet@flexiblespace.com www.flexiblespace.com