Guidance on the Control of Odour and Noise from ... - Defra
Guidance on the Control of Odour and Noise from ... - Defra
Guidance on the Control of Odour and Noise from ... - Defra
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Table 4.3 – <strong>Noise</strong> characteristics <strong>of</strong> different fan types<br />
Fan Type <strong>Noise</strong> Descripti<strong>on</strong><br />
Centrifugal Lower<br />
frequencies<br />
Axial Mid–range<br />
frequencies<br />
Mixed flow Lower<br />
frequencies<br />
Air enters axially <strong>and</strong> is discharged radially.<br />
Air enters <strong>and</strong> leaves <strong>the</strong> fan in a straight–through<br />
c<strong>on</strong>figurati<strong>on</strong>.<br />
The air path is intermediate between axial <strong>and</strong> centrifugal.<br />
Cross flow Varied L<strong>on</strong>g cylindrical impeller with a large number <strong>of</strong> shallow<br />
blades discharging via a l<strong>on</strong>g slot.<br />
Propeller T<strong>on</strong>al peaks Similar to an axial fan, but mounted in a ring permitting<br />
both radial <strong>and</strong> axial discharge, higher volume <strong>and</strong> lower<br />
pressure.<br />
4.6 Access Panels For Cleaning<br />
Access panels should be suitable for <strong>the</strong> purpose for which <strong>the</strong>y are intended. They<br />
should incorporate quick release catches, sealing gasket <strong>and</strong> <strong>the</strong>rmal, acoustic <strong>and</strong><br />
fire-rated insulati<strong>on</strong> properties equal to that <strong>of</strong> <strong>the</strong> duct to which <strong>the</strong> panel is fitted.<br />
The panel <strong>and</strong> aperture should be free <strong>of</strong> any sharp edges. <str<strong>on</strong>g>Guidance</str<strong>on</strong>g> <strong>on</strong> <strong>the</strong> required<br />
locati<strong>on</strong>s for access panels is provided in Table 4.4.<br />
Table 4.4: Locati<strong>on</strong> <strong>of</strong> access panels for cleaning<br />
Locati<strong>on</strong> <strong>of</strong> access panel Cleaning<br />
C<strong>on</strong>trol Dampers Both sides<br />
Fire Dampers One side<br />
Heating/cooling Coils Both sides<br />
Attenuators (Rectangular) Both sides<br />
Attenuators (Circular) One side<br />
Filter secti<strong>on</strong>s Both sides<br />
Air turning vanes Both sides<br />
Changes <strong>of</strong> Directi<strong>on</strong> One side<br />
In Duct Fan/Devices Both sides<br />
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