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Ducts Application Note 

 

VESDA-E 

35424_02 

 

VESDA-E System Commissioning 

 

Hole Orientation Adjustment 

3.1.1  VESDA-E VEP-1P 

The differential pressure across the inlet and exhaust pipes must be kept within ±20 Pa to ensure the normal 
operation of the smoke detector. Differential pressure is created by the orientation of the holes on both pipes 
in relation to the duct flow. There are three methods for adjusting hole orientation. Your choice of method will 
depend on what equipment is available to you. 

1. 

Method 1 takes about 5 to 15 minutes, not including air flow normalization. No special equipment 
required. 

Step 

Action 

Ensure that the ventilation duct system is operating and airflow is present in the duct. 

Drill holes in the inlet and exhaust smoke detector pipes as required. 

Connect the inlet and exhaust pipes to the detector while the pipes are outside the duct. 

Normalize the airflow to the smoke detector and then record the %Flow. 

Insert the inlet and exhaust smoke detector pipes in the duct with the holes facing the 
airflow and record %Flow at the smoke detector. 

Slightly rotate the pipes so that the %Flow is within 5% of the original reading. 

Mark the position of the pipes’ orientation on the duct and pipes. This will make re-
positioning the pipes easy after maintenance checks in the future. 

Secure the pipe installation. 

 

2. 

Method 2 requires no connection to the smoke detector. Inlet and exhaust pipes are installed inside the 
duct. A manometer, for instance, Model 8702 DP-CALC Micromanometers from 

www.tsi.com

 will be 

required. 

Step 

Action 

Connect the ends of the inlet and exhaust smoke detector pipes to a pressure manometer 
as shown (Figure 8), ensuring that all connections are airtight. 

Face the holes of both pipes to the airflow and slightly rotate the pipes so that the pressure 
reading is within ±20 Pa. 

Mark the position of the pipes’ orientation on the duct and pipes. This will make re-
positioning the pipes easy after maintenance checks in the future. 

Connect the detector after securing the pipe network. 

Содержание VESDA-E VEP-1P

Страница 1: ...DUCTS APPLICATION NOTE February 2021 Doc No 35424_02...

Страница 2: ...mation contained in this document will assist you when designing VESDA E systems for this type of application Note This system is not suitable for use in flexible ducts Related Products VESDA E VEP 1P...

Страница 3: ...1 3 2 VESDA E VEA 5 2 VESDA E System Installation 6 Environmental Conditions 6 2 1 1 VESDA E VEP 1P 6 2 1 2 VESDA E VEA 7 Key Installation Considerations 7 3 VESDA E System Commissioning 8 Hole Orien...

Страница 4: ...a quarter of the height of the duct Figure 1 Side view of the inlet and exhaust pipe positions for a small ventilation duct A top view of the above installation is shown below Figure 2 The number of...

Страница 5: ...m 0 66 ft 1 1 2 VESDA E VEA Return air sampling is achieved with microbore tubes for VEA system inserted in the return air duct behind the exhaust grill it is recommended the tubes are installed facin...

Страница 6: ...commended that the inlet pipe of the smoke detector be in two branches The figure below Figure 5 shows a side view of a duct section with the relative insertion points for the inlet and exhaust pipes...

Страница 7: ...le spacing is 0 4 m 1 3 ft The exhaust pipe must have 4 10 mm 13 32 inch sampling holes regardless of the width of the duct These holes should be located in the middle of the duct width at least 50 mm...

Страница 8: ...uct is poor it is recommended that all holes on the inlet and exhaust pipes face downstream that is 180 to the incoming airflow The pipes should always be held in position at the duct walls with fitti...

Страница 9: ...tside the duct where the detector is to be installed and the temperature of the air inside the sampling pipes of the detector You should measure the temperature and humidity both inside the duct and i...

Страница 10: ...ream of humidifiers heating coils and filters Upstream of fresh air intakes For a smoke detector mounted on the duct ensure there are no tangible vibrations when the duct system is in full operation I...

Страница 11: ...nd then record the Flow 5 Insert the inlet and exhaust smoke detector pipes in the duct with the holes facing the airflow and record Flow at the smoke detector 6 Slightly rotate the pipes so that the...

Страница 12: ...xible tube containing water as shown Figure 9 ensuring all connections are airtight 2 Face the holes on both the inlet and exhaust pipes to the airflow Slightly rotate the pipes so that the water leve...

Страница 13: ...tector Cover the electronics during this test with a sheet of paper 5 Introduce smoke inside the detector s interior housing using a smoke can 6 Place the smoke can s nozzle 0 5 m 1 5 ft away from the...

Страница 14: ...1 Check flow readings at the smoke detector s Differences in flow readings from those of previous site visits require further investigation such as inspection of the pipes sampling tubes integrity for...

Страница 15: ...mendation on system design Xtralis has not assessed the recommendation on system design for compliance with any codes or standards that may apply nor have any tests been conducted to assess the approp...

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