Tecomak has provided fume cupboard testing and maintenance services since its conception in 1974. We have a wealth of experience with all designs of fume cupboard. We currently test and maintain fume cupboards at over 600 sites across the UK including many of the leading research and technology sites.
Our team of skilled engineers can resolve any fault you may experience with your fume cupboards, common problems include;
Fan motor failures due to weather damage
Corrosion to mechanical components
Airflow alarms requiring calibration
Gas and water leaks and jams
Damaged work surface seals
Cracked and leaking ductwork
Jammed sash systems
Faulty airflow sensors
Broken sash glass
At Tecomak we believe a quality preventative fume cupboard maintenance programme can significantly reduce the frequency and duration of breakdowns. We can service all makes and type of fume cupboard and hold common parts in stock.
We listen carefully to our clients' requirements and continuously seek improvement to our service. Being flexible and working around the access constraints that exist we aim to minimise disruption.
Fume cupboards are a class of Local Exhaust Ventilation (LEV) and as such must be regularly inspected in accordance with the regulations on LEV COSHH testing (at least every 14 months). For compliance with HSG 258 a thorough examination and test must be performed of the whole system including ductwork and external fan.
The most common means of fume cupboard testing to check performance is to conduct a face velocity test in accordance with BS EN 14175-4:2004. The aim of the test is to determine any variation from the commissioning test results. For each position within the grid of measurements recorded a mean velocity is recorded. No position means should vary by more than 10% from the design value.
The BS EN 14175-3:2003 standard describes the standard and details where the measurements should be taken (probe positions) for vertical and horizontal sash openings. Measurements at each probe position are taken for at least 30 seconds.
Fume cupboards which have not previously been type tested and commissioned in accordance with BS EN 14175 should undergo containment testing to ensure their current performance is deemed safe. The aim of a containment test is the quantification of the containment under the prevailing working conditions. Containment efficiency can be affected by many factors but the main ones are:
Face velocity and stability of velocities across the aperture.
Room air velocity surrounding the fume cupboard (turbulence from other sources)
Proximity to heat sources (lab equipment, glazed areas, radiators etc)
Presence of equipment inside the fume cupboard and obstructions outside the cupboard.
As specified by BS EN 14175-3:2003 section 5.3, the containment test can either be performed in the inner measurement plane, or in the outer measurement plane or in both planes. The fume cupboard test equipment must be as described by BS EN 14175-3, 5.3.1 and includes use of an infra-red gas analyser connected to a PC which allows real-time display of the data as a trace of leakage (ppm) against time. A gaseous challenge of sulphur hexafluoride (SF6) in nitrogen is injected into the enclosure at a precisely controlled rate to simulate the release of contaminant inside the cupboard. An array of sampling heads is positioned at the enclosure aperture and allowed to collect any SF6 which is able to migrate across the boundary, against the prevailing airflow. Measurements are repeated with the array in six positions across the aperture.
We generally recommend containment should be < 0.005ppm. Values greater than this should be investigated, the cause rectified and the correction verified by re-test.