Connections; Duct Connections - VENCO VHR Series Installation, Operation, & Maintenance Instruction

6. CONNECTIONS

6.1. Duct Connections

Return air, fresh air, exhaust air and supply air ducts should be fixed (connected) to the unit with flexible
connection. Required leak-proofing should be obtained in order to ensure desirable air flow. Having improper
(bad) unit – duct connections and wrong dimension, shape and duct fragments inside of the connection may
cause turbulence.
Free Flowing Status; Centrifugal fan which is outgoing directly, is a poor efficient exhausting system That
turbulence can disappear with an additional duct or with an additional expansion part. It is more important
when the applications for orifice and distributor which use laminar method for pressure calculation.
Turbulence causes increasing the pressure loses. ( Figure 6.1.1).
Figure 6.1.1 In.Free Outlet
It is very important to make the connection between flowing the unit connection and flexible connection
carefully to prevent noise and vibration Fan input and duct axis have to be proper and flexible connection
should not be an accordion. Air passage has to be smooth. (Figure 6.1.2).
Figure 6.1.2. Ducted Outlet
.
Figure 6.1.3. Unit Duct Connection
When air flow direction is changed at fan blowing outlet, excessive losses may occur. If this is compulsory,
connections should be done as Figure 6.1.4. The length of duct, before the elbow or electrical heater, should
be double of the outlet-diameter
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