EN 1751-2014 pdf download.Ventilation for buildings – Air terminal devices – Aerodynamic testing of damper and valves.
Damper leakage performance could vary depending on whether the damper is subjected to positive or negative pressure. The manufacturer shall specify the pressure conditions for test.
5.2 Damper and valve leakage
5.2.1 Measurement of damper and/or valve leakage in the shut-off position shall be made under conditions of actual operation with the damper or valve closing against the maximum recommended static pressure conditions. Since small flow rates exist during the closed damper or valve condition, the method used to measure these small flow rates will introduce a high pressure loss when the damper or valve is open. This precludes a high pressure difference in the inlet duct until the damper or valve approaches the closed position.
BS EN 1751:2014
EN 1751 :2014 (E)
As the valve is closed and the flow rate decreases, the inlet static pressure difference will increase to approximately the recommended inlet pressure.
5.2.2 The dampec or valve shall be cycled 10 times between the fully open and fully closed positions of the actuator at the start of each test (before starting the fan of the air supply system) concluding with the damper or valve in the fully closed position.
NOTE In all cases in the closed position, the damper drive is subject to a torque rating recommended by the manufacturer.
5.2.3 The damper or valve under test shall be connected to a test installation similar to that shown In Figure la) or Figure ib)). A suitable air supply shall be connected to the duct. In both cases, care shall be taken to ensure that duct joints are sealed to manufacturer’s instructions.
5.2.4 The supply air pressure shall be Increased to the maximum recommended inlet pressure difference In accordance with the appropriate classification from Figure C.1 and Figure C.2. The damper or valve is then modulated to the open position, without any additional adjustment of the supply air system flow rate, and then returned to the closed position either manually or by the means provided by the manufacturer. The supply air pressure shall be adjusted. as the damper or valve nears closure, to maintain the recommended inlet static gauge pressure difference within i 5 %. The above process is to ensure that the closed condition is as representative as possible of typical operation with airflow present.
NOTE The air flow measuring device for leakage measurement may have to be disconnected in the above process to avoid any potential damage to a device for measuring low air rates.
5.2.5 Report the damper or valve air leakage factor as a function of test pressure difference in the closed position. Also include classification (see Annex C).
5.3 Casing leakage
5.3.1 The test installation shall be similar to that shown in Figure 2 a)) or Figure 2 b)). The damper or valve casing outlet shall be sealed according to the instructions of the manufacturer. The damper or valve shall be set to the open position.
5.3.2 The test of the casing shall be carried out by subjecting the casing to its maximum recommended pressure in accordance with 5.2.4. The pressure shall be maintained for 60 s before the measurement of leakage commences.
5.3.3 Report the test results as casing air leakage factor as a function of test pressure. Also include classification (see Annex C).
6 Flow rate and pressure tests
6.1 Ducted method
6.1.1 This method applies for dampers or valves mounted within a duct.
6.1.2 The damper or valve under test shall be mounted in a system comprising a fan, a means of controlling air flow rate, a flow rate measuring system and test ducts (see Figure 3).
6.1.3 The test ducts shall have cross-sectional dimensions equal to the nominal size of the unit under test or to the manufacturers instructions. The upstream test duct shall be straight for a minimum length of 5D.1. The downstream test duct shall be straight for a minimum length of 50,2 or 2 m. whichever is the greatest.EN 1751-2014 pdf download.