GUIDANCE: Verification - The Wet Film Thickness Test
How do I know my ductwork is clean enough?
After you've had a professional duct clean, you may be wondering how to check the cleanliness of your ductwork, and what required by most compliance bodies and insurers? BESA's TR19 (the standard the commercial kitchen industry works to in relation to the cleanliness of extraction systems) uses the Wet Film Thickness Test to verify the cleanliness of ductwork. This is a precision test, carried out using a gauge.
The gauge is placed at ninety degrees to the coated ductwork surface. Once the gauge is removed, the value of the largest tooth that is wet, and the smallest tooth that is not wet is noted. The wet film thickness lies between these two values.
TR19 standards require the following measurements:
If the wet film thickness is at 200 μm as a mean across the entire extraction system, complete cleaning is required.
If any single measurement of wet film thickness is above 500 μm, then urgent localised cleaning is required.
Cleaning Recommendations | Action |
| 200 μm (as a mean across the system) | Complete cleaning required |
| Any single measurement above 500 μm | Urgent localised cleaning required |
How Vent AIR can ensure wet film thickness lies below 200 μm continually.
You'd think having your ductwork cleaned professionally every couple of months would ensure your extraction system is clean and meets requirements. After all, it's an expensive business - organising the clean, shutting down the kitchen whilst the clean is carried out and training staff on post-clean procedure. However, do you know how long it takes grease levels to creep up above 200μm? How long does your ductwork actually remain a low fire-risk post-clean? And can you be sure the wet film thickness is below 200μm along the entire route of the ductwork? What about the risers and hard to reach corners?
Vent AIR is a holistic solution. It is not a 'fit and forget' concept that is left to operate in the background. Once Vent AIR has been installed, the Vent team carry out post-installation inspections throughout the year to help ensure your ductwork is kept continually clean. Vent AIR does not merely treat the problem. It prevents the build-up of grease from the outset, so that your kitchen extraction system is safe and a low fire-risk. Vent works with you to formulate a service plan that meets your individual needs, depending on your cooking frequency, usage, extract infrastructure and cuisine.
Our mission is to transform the way extraction systems are currently cleaned with intelligent biotechnology. And why is it intelligent? Because it is low on VOC content yet highly effective - just as effective as using solvent-based cleaners. It is safe and low on environmental impact. It can also save hugely on operational and compliance costs - there is no need to organise professional duct cleans throughout the year, or to stop kitchen operation. Vent AIR helps to meet insurers requirements too, meaning you could save on your yearly premium.
Give us a call to see how Vent could revolutionise your kitchen operation. Call 03300 415 396 or email enquiries@bio-vent.co.uk.
