Make a change and save up to 85% on lab energy costs 

The rise in energy prices and the climate change crisis are motivating us all to think about how we can operate our homes, civic infrastructure, businesses and other organisations more sustainably.

Science is at the forefront of finding solutions to these global challenges, but research is energy-intensive and lab managers are also under pressure to keep energy costs and usage down, without compromising on safety.

Where can energy savings be made?

One area to consider is the ventilation of fume cupboards. A vital piece of lab equipment, it’s also one of the most energy-intensive[1], pulling air from inside the room through the open sash and taking hazardous and noxious gases with it. The contaminated air is then expelled or filtered for re-circulation.

Constant Air Volume (CAV) ventilation requires a continual flow of air, regardless of whether or not a fume cupboard is in use (or its sash is open or closed), wasting energy and increasing costs. The average fume hood exhausts between 750 and 1,000 cubic feet of conditioned air per minute.  Or to put it another way, a single fume cupboard running on CAV uses as much energy as a medium sized family home over a 24 hour period!

Closing the sash on a CAV hood can also increase the pull at the front of the fume cupboard which can disturb equipment, slow experiments down and even send contaminated air back into the room.

Switch to Variable Air Volume ventilation

By contrast, a Variable Air Volume (VAV) system reduces the volume of air taken from a fume cupboard when it’s not in use and the sash is closed, ensuring energy use aligns more closely with user needs.

Switching to a VAV system (which can be fitted as part of a new installation or retrofitted in any existing laboratory) can reduce energy usage by up to 85%, reducing costs and helping lab managers meet carbon reduction targets.

  • Average energy cost savings of VAV over CAV airflow control = £1,271 per fume cupboard per year.
  • Average energy saving of VAV over CAV airflow control = 35,475 kWh per fume cupboard per year.

The Case for VAV airflow control

We recently worked on the re-fit of a large laboratory with Total Containment Solutions a leading supplier of fume cupboards for industrial and educational laboratories. The project, which included the installation of 65 non-standard fume cupboards, had to demonstrate tangible energy savings to the international contract research organisation that would be using the space.

Because the cupboards were purpose built, they went through rigorous type testing, factory acceptance testing and site acceptance testing to ensure they complied fully with BS EN 14175.

They were also fitted with TEL’s energy saving AFA1000/E airflow controllers. Accredited by the Carbon Trust, these VAV airflow controllers significantly reduce the energy needed to ventilate fume cupboards, while providing the highest standards of safety and comfort for lab users.

The decision to install VAV over CAV airflow control meant a significant reduction in energy wastage and carbon emissions and significant energy cost savings. These are estimated at:

  • Total annual energy cost saving: £82,615
  • Total annual energy saving: 2,305,875 kWh

Which means the VAV controls will pay for themselves in just over 2 years. 

For full details of this and all our Case Studies go to

Discover TEL’s range of VAV Airflow Control Products

TEL’s range of VAV controls are designed for use with industrial and educational fume cupboards, fume hoods and biological safety cabinets.

Find out more at

[1] University of Cambridge, The Cambridge Green Challenge, []

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