Ducting Information; 6�1 Minimum Recommended Return Air Grille Selection Chart - Kaden KU5 Installer Manual

6. DUCTING INFORMATION

Good duct design and sizing are essential to every Kaden Central Heating system. Use the Kaden Size Guide and
technical data within this manual for the best results and follow these guidelines:
•
Ductwork should be well insulated and airtight and have a minimum insulation rating of R1.0 (R1.5 in some
areas). Ensure that ducting complies with the Building Code of Australia.
•
The ducting should be well fastened to pops, BTO's, outlet boots and neck adapters adequately with duct tape,
in accordance with AS 4254 and HB 276.
•
It should also be properly sized, and curves and bends should be smooth enough to ensure that the air flows
through efficiently, quietly and with minimal resistance.
•
The registers and diffusers should be large enough and of good design. They should minimise noise, while
providing the correct distribution pattern.
•
The positive return air system should be fitted with a grille large enough to accept the full air capacity of the
system at low noise levels.
•
If the system uses high level outlets (e.g. ceiling diffusers), then the return air inlet should be at a low level.
Ceiling systems with a high level return air may result in reduced performance.
•
For all Kaden heaters, access to the ductwork must be provided for general maintenance and service to the
supply air thermistor sensor where applicable.
It is important that the ducting should be well insulated. It is mandatory under building codes to
install insulated, fire rated duct.
NOTE
If a filter is fitted to the return air grille, it should be easily accessible for regular cleaning. Table 5 gives the minimum
recommended return air grille sizes for each model heater to handle the maximum rated airflow.
6.1 MINIMUM RECOMMENDED RETURN AIR GRILLE SELECTION CHART
Model
KU521
KU530
KU415
KU420
KU425
KU430
KU315
KU320
KU325
KU330
KE415
KE420
KE420XA*
KE428
KE428XA*
KE315
KE320
KE320XA*
KE328
KE328XA*
* XA is based on base box POP sizes.
Grille sizes are based on maximum airflow with typical Egg-Crate Grille type. For all other types,
consult grille manufacturer's specifications. For example a grille with a free ventilation opening
NOTE measuring 400mm x 750mm, the grille size is 0.4m x 0.75m = 0.3m2. This grille would be suitable
for a KU521 heater provided the grille does not have a filter fitted.
Without Filter
Grille Size (m²) Example of Size (mm)
0.28 400 x 700
0.36 400 x 900
0.26 400 x 650
0.26 400 x 650
0.26 400 x 650
0.31 400 x 800
0.19 400 x 475
0.22 400 x 550
0.24 400 x 600
0.35 400 x 1000
0.19 400 x 475
0.22 400 x 550
0.24 400 x 600
0.32 400 x 800
0.35 400 x 875
0.19 400 x 475
0.22 400 x 550
0.24 400 x 600
0.32 400 x 800
0.35 400 x 875
Table 5
With Filter
Grille Size (m²) Example of Size (mm)
0.42 400 x 1050
0.54 400 x 1350
0.39 400 x 1000
0.39 400 x 1000
0.39 400 x 1000
0.47 400 x 1200
0.28 400 x 700
0.32 400 x 800
0.35 400 x 875
0.51 400 x 1275
0.28 400 x 700
0.32 400 x 800
0.35 400 x 875
0.46 400 x 1150
0.54 400 x 1350
0.51 400 x 700
0.32 400 x 800
0.35 400 x 875
0.46 400 x 1350
0.51 400 x 1275
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