Controls; Measuring Principle - Lindab LTEST LT 600 Mode D'emploi

3. Controls

Figure 2: Controls

4. Measuring principle

Leakage testing is stipulated in the European Energy
Performance of Buildings Directive (EPBD) and in
standards like
DIN EN 13779, in order to save energy and to ensure
that air conditioning and ventilation systems operate
efficiently .
The airtightness of duct systems is tested by bringing
the system to a constant test pressure, then measuring
the leakage flow rate that must be supplied in order to
maintain this pressure .
This flow rate corresponds to the leakage rate of the
duct section being tested . The test conditions are
described in DIN EN 12237 for circular ducts and in DIN
EN 1507 for rectangular ducts . DIN EN 1751 contains
the test conditions for dampers and valves, and DIN
EN 15727 covers other air conditioning and ventilation
components .
The leakage tests should be carried out in situ as
described in DIN EN 12599 (usually at lower pressures
as described in the product standards) – "DIN EN
12599 Test procedures and measuring methods for
handing over installed ventilation and air conditioning
systems" .
VOB C stipulates that acceptance testing must be car-
ried out in accordance with DIN EN 12599 .
1 Power switch
2 Bayonet connection for test pressure (positive
pressure)
3 Connection for differential pressure (negative
pressure)
4 Infrared interface for TD600 thermal printer
5 50 mm diameter air connection - negative
pressure
6 OLED colour display
7 Rotating handle
8 Membrane keypad
9 USB port
10 50 mm diameter air connection - positive
pressure
11 Power supply
The diagram below illustrates the test setup concept .
• Two integrated fans blow/extract air through the Ø50
mm hose into/out of the connected duct system(s)
being tested . The air supply causes the pressure
in the duct system to increase . This pressure is
returned to the device via the connected pressure
measuring tube .
• In automatic mode, the device automatically brings
the system pressure to the selected test pressure .
Figure 2: Measuring principle, leakage test with the
Lindab LT 600
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