CEILING DIFFUSERS technical types -CD, CAB Europair Africa a division of Performancair Products Africa (Pty) Ltd tel +27 11 974 2425 fax +27 11 974 7251 web www.europair-africa.com email: info@europair-africa.com Cnr. Grader and Vuurslag Spartan Ext. 3 Kempton Park Johannesburg
02 Details FIXED BLADE CEILING DIFFUSER - CD Versatility is the key to why the popular directional or pattern-type diffusers are being used so widely for so many different applications. Recommended for heating, ventilation, and cooling, the directional type diffuser provides directed air diffusion, channelling the designed amount of conditioned air into the areas where it is needed. Available in a wide range of sizes, both square and rectangular. There's the choice of one, two, three, four way patterns segmented in rectangular, corner, "y" or diagonal configurations. This takes care of and permits changes as the use or arrangement of conditioned space is varied. The desired versatility is designed into the diffusers. Offered exclusively in extruded aluminium, the diffuser models provide the best robustness and durability combined with inflamibility in directed air diffusion. The core is easily removable for access to the duct. The frame and core are constructed of 1.25mm thickness extruded aluminium. All models can be supplied with a surface finish off temperature-set white powder coated paint preceded by a seven-stage preparation process of degreasing, acid bathing and passivation. This process ensures proper paint adhesion which provides long lasting aesthetics and durability. To enhance the appearance of the units, the finest available paints are used which can be matched to your colour requirements. Optional aluminium paint is available at no extra charge. There are two frames available depending on the application in use. The flat frame is standard whilst a bevelled frame can be supplied on request. ADJUSTABLE BLADE CEILING DIFFUSER - CAB Further versatility is added to the diffuser range by way of adjustable blades. A similar range of blow patterns as for fixed ceiling diffusers are available. Adjustable blades allows ultimate control in the direction of flows. FEATURES All Aluminium construction offers exceptional quality and performance. Light in weight. yet strong and durable. Wide range of sizes, both square and rectangular, Other finishes available upon request. Complete selection data to ensure quiet, draft less air distribution. Tested and rated in accordance with specifications.
03 Details The performance data which follows permits quick, easy and accurate selection of diffusers. Two groups of data are required for selection. The first group is that established by the structural and room-use considerations. The second group consists of the performance characteristics of the diffusers. Consider first the spaces which are to be conditioned and their effects upon outlet selection. AIR FLOW The performance data which follows permits quick, easy and accurate selection of diffusers. Two groups of data are required for selection. The first group is that established by the structural and room-use considerations. The second group consists of the performance characteristics of the diffusers. Consider first the spaces which are to be conditioned and their effects upon outlet selection. TABLE 1 - Recommended NC Level Design Goals NC LEVEL The permissible sound level in each space may be specified by the owner or the architect, or it may be determined as an engineering design goal. Table 1 contains an abbreviated list of design goals for air-conditioning sound control in common occupancies. Pattern Requirement The pattern requirement is determined by the shape of the space to be conditioned, the number of diffusers in it, and the type and location of lighting fixtures or other devices mounted on the ceiling. For example a two-way opposite 2A, 2B or 2C - might be used in a corridor. A larger area can often be divided into squares or rectangles of nearly equal size and, if a diffuser can be located in the center of each of these areas, patterns 4A or 4B could be used for four-way delivery. Throw Requirement The required throw is determined from the building plan after the diffuser location has been decided. The throw requirement is the distance from the diffuser to the nearest enclosing wall. In some cases the throw requirement will be the distance from the diffuser to the intersection of its air stream with air being delivered from another diffuser. For high ceiling applications, the throw requirement may be measured as the horizontal distance described above plus the vertical distance from the diffuser to occupied zone. This is usually considered to extend to the 1,5m level in the room. Another consideration is diffuser mounting height. As air travels from a diffuser, room air is entrained into the supply air stream and the delivery pattern thickens. If the throw requirement is too great, the lower part of the supply air stream can intrude into the occupied zone of the conditioned space. To avoid this, diffusers should be located so that the throw requirement is no greater than 1.5 times the diffuser mounting height. For example, in a space with a 3.6m ceiling height diffusers should be so located and in such numbers that the required throw of any one diffuser Vi/auld not exceed 5.5m. The final consideration is the pressure loss of the diffuser.
04 Details TABLE 2 - Recommended Max Throw Requirement The basic selection data in Tables to follow for all directional diffusers. The table list performance data as a function of the air velocity in the neck of the diffuser. It lists several sizes for each core pattern and gives the neck area, expressed in m2, for each diffuser size. Performance factors listed are the air volume delivered through the diffuser, the NC level, the air volume delivered through each side of the diffuser, and two values of throw. The values of throw shown in the Tables are bases upon studies of air motion in the occupied zone under conditions of cooling system operation. When a diffuser is equipped with an opposed blade damper (OBD), both the total pressure requirement and the NC level increase. The OBD increases the total pressure requirement of a diffuser by 10 percent. The NC addition, when the OBD is wide open, can be determined from Table 4. When the OBD is throttled, the NC factor for the throttled damper can be determined from Figure 17. The opposed blade action of the damper permits equal distribution of air over the entire face of the diffuser. The operating mechanism provides for positive damper setting in a position from fully open to fully closed. See holes on OBD for additional information. ADDITION TO OPEN DAMPER NC TABLE 3 - Velocity Pressure The allowance in the design of the system for outlet pressure loss should not be exceeded by the diffuser pressure loss. The room velocity, YR, should not exceed O.6m!s when the diffuser selection is based upon minimal throw. When diffuser selection is based upon maximum throw, the room velocity, YR, should not exceed O.4m!s. The tabulated values of throw apply for diffusers mounted in a ceiling. Selection data are given for neck velocities ranging from 1.5 to 3.5m!s Also listed are values of total pressure drop through the diffuser at each of these neck velocities. The total pressure requirement is the sum of the static pressure drop of the air as it passes through the diffuser and the velocity pressure of their air at the neck of the diffuser. If the static pressure is required, it can be determined by subtracting the velocity pressure from the total pressure. TABLE 4 - NC ADDITION FOR DIRECTIONAL DIFFUSER WITH OBD.
05 Type - CD Dimensions: "D" Celing Opening Over Flange = Outside Neck = "D" + lomm = "D" + 120mm Dimensions: "D" Celing Opening Over Flange = Outside Neck = "D" + 75mm = "D" + 130mm TYPE CD: Ceiling Diffusers manufactured from Anodised Aluminium with Removeable Cores Accessories OBD = Opposed Blade Damper remains in position when core is removed PB = Plenum Box with spigot CP = Ceiling Plate Note 1. PB Fits over neck of CD +/-2mm clearance all round 2. CP Fixed to neck of CD on request only 3. Refer selection data for standard size (increments 76mm) Frame Options SF = Standard Flat SB = Standard Bevel on request only Finish Options NA = Natural Anodised EPC = Epoxy Powder Coating Blade Spacing: 38mm Standard Type CD: Ceiling Diffuser available in a choice of air distribution patterns. Note: T1 is always longer than T2 except in 3A where T1 = T2 All flow patterns are given looking at Diffuser face Ordering Procedure: Example Note: (1) Dimensions given are Outside Neck Size - "D" (2) Type CD Core 3A indicates Ceiling Diffuser with 3 way blow core
06 Type - CD Dimensions: "D" Celing Opening Over Flange = Outside Neck = "D" + lomm = "D" + 120mm Dimensions: "D" Celing Opening Over Flange = Outside Neck = "D" + 75mm = "D" + 130mm TYPE CD: Ceiling Diffusers manufactured from Anodised Aluminium with Removeable Cores Accessories OBD = Opposed Blade Damper remains in position when core is removed PB = Plenum Box with spigot CP = Ceiling Plate Note 1. PB Fits over neck of CD +/-2mm clearance all round 2. CP Fixed to neck of CD on request only 3. Refer selection data for standard size (increments 76mm) Frame Options SF = Standard Flat SB = Standard Bevel on request only Finish Options NA = Natural Anodised EPC = Epoxy Powder Coating Blade Spacing: 38mm Standard Type CD: Ceiling Diffuser available in a choice of air distribution patterns. Note: T1 is always longer than T2 except in 3A where T1 = T2 All flow patterns are given looking at Diffuser face Ordering Procedure: Example Note: (1) Dimensions given are Outside Neck Size - "D" (2) Type CD Core 3A indicates Ceiling Diffuser with 3 way blow core
07 Type - CD General Notes On Selection (i) "TOTAL VOLUME" means Total Volume per outlet. (ii) "THROW MIN-MAX" is to a terminal velocity of 0.75 m/s at Minimum throw and 0, 25rn1s at maximum throw. (iii) "VOLUME T1/T2" means volume per side i.e. T1/T2 = 0,092/0,040 means Volume on T1 = 0,092 and Volume on T2 = 0, 040 (iv) "T1 is always longer than "T2" except on type 3A where T1 = T2. (v) Noise Levels: "A" = Up to 30 dba "B" = 31 to 40 dba "C" = 41 to 50 dba (vi) Ordering: When ordering T1 (longest side) is always given first (vii) Sizes shown refer to over outside neck. (viii) For sizes not shown please contact nearest sales office. (ix) Selection Example: Problem: Select a 4 way blow diffuser to delivery 0,25 m3/s with a throw of 3,5m in all directions. Solution: Use Size 381 x 381 Core 4A, Pressure drop = 15 N/m2. Noise level = A. Performace Data
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16 Ceiling Plate - CP Type CP: Ceiling Plate manufactured of electro galvanized flat sheet for installation in lay-in "T" Bar suspended ceiling system. It is easily relocated to meet changing space requirements. It also fits all common suspended grid ceilings, and are available with epoxy powder coating finish to your colour requirements. Ordering Procedure - Example
17 Type - CAB TYPE CAB: Curved Adjustable Blades - Ceiling Diffuser Manufactured of extruded type 50S Anodising Grade Aluminium with individually adjustable blade. The blades are held in place by plastic friction grommets or wire. Accessories PCS = Punched Counter Sunk Holes OBD = Opposed Blade Damper PB = Plenum Box with spigot CP = Ceiling Plate Frame Options 30mm Standard ON = Over Neck 20mm OS = Over Flange 50mm OP = Opening or Normal Duct Size Finish Options WS = Wet Spray Colour NA = Natuaral Anodised Aluminium Blade Spacing: 19mm Standard Type CAB - Ceiling Diffuser available in a choice of Air Distribution Patterns Note: H1 is always longer than H2 All Flow Patterns are given looking at difuuser face Ordering Procedure - Example Note: (1) Dimensions given are for over Flange size (2) Type CAB Core 2A indicates CAB with two way blow
18 Type - CAB GENERAL NOTES ON SELECTIONS A) TOTAL VOLUME MEANS TOTAL VOLUME PER OUTLET - m3/sec. B) THROW MIN-MAX IS TO A TERMINAL VELOCITY OF 0.64 MIS MINIMUM THROW AND 0.031 MIS AT MAXIMUM THROW. C) VOLUME HI + H2 MEANS VOLUME PER RESPECTIVE SIDE. D) HI IS ALWAYS LARGER THAN H2, EXCEPT ON TYPE 3A WHERE Hl=H2. E) NOISE (NC) LEVEL A = 0-30 B = 31-35 C = 36-40 D = 41-45 SELECTION OF CURVED ADJUSTABLE BLADE GRILLE IS BASED UPON THROW AND M3/S REQUIREMENTS. THE THROW, M3/S AND PRESSURE DROP APPLY WHEN THE INDIVIDUAL BLADES ARE ADJUSTED IN THE MANNER ILLUSTRATED BELOW. OTHER BLADE SETTINGS WILL PROVIDE SIGNIFICANTLY DIFFERENT THROWS AND AIR DELIVERIES. THE M3/S TABULATED IS THE VOLUME DELIVERED BY THE GRILLE. BALANCING OF CURVED BLADE IS ACCOM- PLISHED BY MEASURING FACE VELOCITY. THE MEASURED VELOCITY CAN BE CORRELATED TO TABULATED FACE VELOCITY AND M3/S WHEN THE BLADES ADJUSTMENT IS THAT AS ILLUSTRATED. THE PERFORMANCE OF RECTANGULAR GRILLES WITH AREAS EQUAL TO SQUARE GRILLES, WILL BE THE SAME.
19 Type - CAB SELECTION DATA CORE PATTERN
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