How to eliminate: "Unbalanced circuit of terminal unit "XY"..."

Product	InstalSystem 5
Type of article	TIP&TRICK
Source for translation	2018-03-22

Problem description

The message is displayed when the determined flow rate across the terminal unit is higher than the required flow. Hydraulically unbalanced circuits are diagnosed by displaying the message:

• Unbalanced circuit of "XY" terminal unit (XY% of required flow) - check capabilities of control components in circuit

Unbalanced circuits may result from:

• lack of valves that limit maximum flow or control the flow across the units (e.g. thermostatic valves),
• insufficient control/balancing capabilities of the fixtures used (e.g. excessive kv at minimum setting of the valve),
• incorrect distribution in Tichelmann system (lengths of circuits, between the source and every subsequent terminal unit, should be similar),
• incorrect specification of pipe types and/or pipe diameters for connections of Heating/Cooling Zone or pipe-runs feeding the terminal units (diameters of the feed pipes and of the circuit proper should match).
  Inconsistency in diamters may result in incorrect/excessive use of connecting fittings which increases flow resistance and differences in pressure drops,
• differences in sizes of terminal units or groups of terminal units in a Tichelmann system.

Solution

• Proper specification of pipe types and/or diameters for connections to Heating/Cooling Zone or pipe-runs feeding the terminal units.
  
  
  
• Use flow control components.
  
• Eliminate differences in sizes of terminal units by connecting them in series.