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TSI / Airflow Aircone hood sets

Available for hire

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Aircone hoods are a method to maximise the usefulness of any Airflow / TSI 100mm (4") rotating vane anemometer. For a very modest investment, you can double the capability of your velocity instrument into an air volume flow meter as well.

Commissioning and balancing of air volume flow is immediately possible at grilles, diffusers and air valves. The hoods are equally suitable for measuring ventilation flow rates for both extract and supply air.

Please note that the aircone kit does not include a vane anemometer, see the technical page for more details.

Product Features

  • 2 model types
  • Document downloads
  • Instrument FAQs

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Manufactured in hard wear ABS for the rigours of on-site use. All sizes are extremely lightweight allowing one man operation for long periods and one handed testing up ladders etc. when used with appropriate anemometer.

Using the Aircone is simplicity itself. Just clip your 100mm (4") rotating vane into the collar of the hood with the sensor pointed into the direction of flow, i.e. for extract or supply. Fit the hood over the inlet / outlet to be balanced and hold in place so that the flange creates a seal with the overall dimensions of the grille or diffuser under test.

Where grilles are larger than the size of the hood it is suggested that the area is divided into equal areas, avoiding overlapping where possible, then a series of readings are taken, adding together and averaged to calculate total volume flow.


  • Aerodynamic design for minimal resistance.
  • Direct reading of volume flow rate with instruments having area input facility.
  • Volume flow curves in m³/sec and cfm for velocity measuring instruments.
  • Self sealing for leak tight readings.
  • Tough ABS to take knocks on-site.
  • Compatible with all Airflow / TSI 100mm (diameter) vanes.



  • Converts 100mm vane anemometer into flow meter.
  • Inexpensive commissioning.
  • Saves you money - one man operation.
  • Proportional balancing made really easy.
  • Suitable for extract and supply.
  • Carry case (round and rectangular hood kit).



  • HVAC grilles, diffusers, linears, air valves.
  • Commissioning and testing engineers.
  • Containment area checks, safety cabinets
  • Fan inlets / outlets, VAV systems, filter conditions, dampers.
  • Leakage checks.


Rectangular hood - 285mm x 235mm
Round hood - 180mm diameter
Weight 1.1kg.

Important notes :

If required a compatible 100mm (4") vane anemometers must be order separately to use this product and all calibrations must be conducted in conjunction with this anemometer.

If this product is to be used for the testing of a ventilation system covered by Part F of the Building Regulations it is required to have a UKAS calibration for air volume in conjunction with an anemometer to comply with the guidance documentation.

Unless there is any specific guidance offered by the manufacture of the ventilation system, due to the size and shape of the round hood, BSRIA Instrument Solutions does not recommend the use of the circular products for the testing ventilation systems to Part F of the UK Building Regulations. If however the circular hood are to be used we would recommend that the hood + anemometer + grille combination is calibrated by a UKAS accredited laboratory for air volume to determine the system characteristics, as errors can be significant without applying the appropriate correction factor at the measured flow rate. A price for this service can be obtained from BSRIA Instrument Solutions calibration department on calibration@bis.fm

When using any hood kit it is recommended that there is a minimum of 50mm clearance between the fan inlet/outlet grille and the hood. Furthermore if testing fans with an inlet/outlet grille on the side of the product a clearance of at least 100mm should be made to reduce measurement errors. For measurements in these applications BSRIA Instrument Solutions recommends a product such as the Alnor LoFlow balometer with its larger hood assembly.



NHBC ventilation guidance note January 2014

  • Technical Document
  • PDF file
  • 659 KB

TSI / Airflow AirCone PD Vs. Flow data sheet

  • Technical Document
  • PDF file
  • 21 KB



Can I use any 100mm vane anemometer with the Aircone hood ?


Yes but please check with our sales department to check compatibility. Also the equipment must be calibrated for volume flow so that the errors in the complete system are known.


Will the Aircone hood put a back pressure on the system being tested and this influence the results ?


The instrumentation can create a back pressure on systems especially at volume rates above 20l/s.  However, as they are often used as proportional balancing tools this effect is the same on each part of the ventilation system being checked and the overall balancing ratio's remain constant.  If the product is to be used for testing to Part F of the Building Regulations this must be UKAS calibrated for volume flow with the appropriate anemometer. 

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