GDD - Supply Grille. Halton GDD. Supply Grille

Transcription

1 Halton GDD Supply Grille Horizontal supply, for circular duct installations For cooling and heating applications; suitable also for exhaust Adjustable vertical front vanes, adjustable horizontal rear vanes Steel construction Visible screw fastening Product Models and Accessories Model with wax-bulb actuator for directing the supply air jet in heating operation Inclined airflow adjustment damper Opposite blade damper for airflow control MATERIAL AND FINISHING PART MATERIAL FINISHING NOTE Frame Steel Polyester-painted, Grey RAL % gloss Special colours available Epoxy-painting (100 %) available Vanes Steel Polyester-painted, Grey RAL % gloss Special colours available Epoxy-painting (100 %) available ACCESSORIES ACCESSORY CODE DESCRIPTION Airflow adjustment damper (1) OD Aluminium opposite blade damper for flow adjustment Inclined airflow adjustment damper HM Galvanised steel inclined damper for flow adjustment Wax-bulb actuator MT The actuator controls the vane angle depending on the supply air temperature 1

2 Function Supply air is supplied into the space with either horizontal and/or vertical deflection. The supply air mixes with room air in front of the grille. The supply air is directed horizontally with the adjustable rear vanes. The length and form of the flow pattern can be adjusted by turning the vertical vanes. The rear vane angle can also be controlled by an optional wax-bulb actuator. Accessories Wax-bulb actuator In applications where both heating and cooling are provided, the air pattern can be changed automatically via a wax-bulb actuator. The wax-bulb actuator alters the angles of the horizontal rear vane depending on the supply air temperature. Neither auxiliary energy nor a dedicated control system are needed. When cold air is supplied at a temperature up to 18 C the supply jet is horizontal. The vane angle is 0. As the supply air temperature rises, the actuator piston progressively changes the angle of the rear vanes in order to direct the supply air jet downwards. The vane angle reaches 45 in 10 to 20 minutes. No maintenance is required for the wax-bulb actuator. DIMENSIONS LxH L1 L2 H1 H2 DUCT SIZE 415x to x to x to x to x to x to x to x to x to x to 1800 Total depth with OD - airflow adjustment damper = 52 mm + 45 mm Total depth with HM - inclined airflow adjustment damper = 117 to 142 mm The free area of the GDD is 62 %. No special dimensions are available. L2 L1 52 H1 H

3 Pressure drop, throw pattern and sound data, supply Exposed duct installation without Coanda effect, vanes at 0 angle Selection example : Requirements : qv = 250 l/s Selection : GDD-575x155 LpA < 35 db(a) LpA = 32 db(a) L0,2 < 16 m L0,2 = 15 DPtot = 9 Pa Note : When the distance between GDD and ceiling is less than 200 mm (coanda effect), the throw pattern is approximately 1.41 times the value of the diagram. Throw patterns shown in the diagrams are based on isothermal air. When heated or chilled jets are considered, the distance of projection changes due to the change in air density. Please, refer to the Halton HIT Design. 3

4 Sound power level with od damper Use of an OD opposite blade damper, will result in increased pressure loss. The resulting increase in sound level is computed from the selection chart value and the formula below: LpA = DLp + LpA Kp= Adjusted pressure drop Pressure drop in selection chart Example : GDD-575x155 qv = 250 l/s LpA = 31 db(a) without damper OD/GDD DPs= 50 Pa (desired pressure drop) Kp = 50/9 = 5.5 LpA = = 48 db(a) Throw length correction factor When the throw length is adjusted with the rear vanes, the actual throw length is obtained by multiplying the value obtained from the selection chart by the correction coefficient K1. L0.2 (a) = K1 x L0.2 The correction coefficient K1 is the average for the various grille sizes. Pressure drop correction factor Angle between vanes When the throw length is adjusted with the rear vanes, the actual pressure drop is obtained by multiplying the value obtained from the selection chart by the correction coefficient K2. DPs (a) = K2 x DPs The sound level increases when pressure drop is increased. The correction coefficient K2 is the average for the various grille sizes. Angle between vanes 4

5 SOUND LEVEL DATA qv DPst DPtot F (Hz) LpA NR NC (l/s) (m 3 /h) (Pa) (Pa) [db(a)] GDD-415x GDD-495x GDD-575x GDD-415x GDD-495x GDD-575x GDD-495x GDD-575x GDD-495x GDD-575x LpA values presented with room attenuation 4 db (red 10m 2 - sab). When using room attenuation 8 db (red 25m 2 - sab): LpA - 4dB. NR/NC noise criteria 5

6 Installation The grille is connected directly to the duct. For the size of the installation hole, see Dimensions page (LxH). The grille is fastened to the duct with visible screws in pre-drilled holes in the frame. Product Code GDD/S-L-H S = Model N M Standard With Wax bulb actuator Adjustment The airflow rate can be adjusted when the grille is installed with the airflow adjustment damper OD or with the inclined airflow adjustment damper HM. The airflow is adjusted by either - turning the OD damper blades behind the grille with a screwdriver or - sliding the moving part of the HM damper Servicing Remove the grille by unscrewing the visible fixing screws. Clean the parts by wiping them with a damp cloth. Push the grille back into place and screw in the fixing screws. L = Length 415, 495, 575 H = Height S=N and L=415: 72, 115 S=N and L=495: 72, 115, 155, 195 S=N and L=575: 72, 115, 155, 195 S=M and L=415: 115 S=M and L=495: 115, 155, 195 S=M and L=575: 115, 155, 195 Specifics and accessories CO = Colour G Grey W White X Special colour Code example Suggested Specifications GDD/N , CO=G The grille shall be made of steel polyester-painted with grey (RAL 7004) standard colour. The grille shall have adjustable horizontal rear and vertical front vanes. Sub products OG Opposed blade damper (GDD) HM Inclined damper (GDD) The frame shall comprise a sealing gasket. The grille shall be fastened directly to the circular duct with visible screws. The grille shall be installed with an airflow adjustment damper. The grille shall be removable for cleaning purposes and to provide access to the circular duct. Optionally The supply air jet shall be controlled according to supply air temperature by a wax-bulb actuator. 6