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E-coli bacteria

You have a filtered air supply system? The the filters were recently changed out? Should be all compliant then?

Sorry team, its not quite that easy. Particulate matter is coming through those air filters, as we speak!

To quote this Camfil article, with outdoor air carrying 200 to 1,500 bacteria per cubic metre, an air-conditioning system with a capacity of 10,000 m3/h can potentially take in 2 to 15 million bacteria each hour and seriously contaminate food & beverage production

Scary stuff!

All air filters are designed to capture a percentage (important point,) of the particulate matter (i.e. dust, soot, smoke, pollen, mould, bacteria) suspended in the air passing through them.

(And that’s making an assumption that there are no leaks around the filter holding frames or supply air ducting – letting 100% of that particulate matter through!)

So what happens to the percentage that is not trapped in the filters? It all passes through to the clean side of your air filters and travels on through the components of your ventilation system, eventually finding its way into your clean factory environment.

Dirty condenser coil

Okay, lets be clear about this. We are only talking microscopic particles, within the acceptable air quality standards of your factory.

However, that does not take away from the fact that this particulate matter is building up internally in your HVAC system, clogging condenser fins, creating bacteria colonies around heat exchangers and contaminating supply air duct work.

If this accumulated foreign matter is not cleaned away and the surfaces sanitised, sooner or later it’s not hard to see that you are going to have issues with the air quality in your factory.

So, what is the answer?

A documented, annual hygiene cleaning schedule for your ventilation system will solve this issue for you. This will compliment the mechanical servicing and filter replacement programs you have in place currently.

This is not usually a task undertaken by factory operators or refrigeration engineers. Look for a reliable ventilation hygiene contractor who has the correct equipment, training and experience to clean and sanitise your:

filter rooms
air plenums
air supply fans
air supply ducting
condenser coils
condenser drain trays and pipework
air diffuser grilles

How often do I need to inspect and clean my Ventilation system?

This will depend on the environment outside your factory and the standard of air quality required inside your factory. The best answer is to engage an IAQ consultant to establish this for you.

In the meantime, as a guide, the standard BS EN 15780:2011 contains the following table for recommended inspection intervals.

Get this in place and you can rest easy that the amount of bacteria entering your factory is under control!

About the Author.

Matthew Prestidge is an Industrial Hygiene and Clean Air consultant for Presco Environmental Services in New Zealand. Creating more sustainable environments on industrial sites since 2006, Matthew has seen the good, the bad and the ugly and knows what is required to “clean up”.

Matthew offers a free consultation and professional advice to the food industry for any industrial cleaning or hygiene issue. Contact him at matthew@presco.co.nz

It is the time of year again for Dairy Factories to perform their winter maintenance tasks. This includes the very important replacement of any HVAC air filters that are due to be changed out.

While this diligent attention to air quality is great, how do you make sure that when you disturb these air filters, all of the dirt and pathogens collected up in them over the last season does not become air-borne again and end up contaminating your factory?

Even more importantly, how do you make sure the service technicians are not risking their health when handling these bacteria-ridden, allergen-inducing objects?

Here’s some trade tips to help you do a good job of this.

Protect yourself from air-borne contaminants by wearing a well-fitted respirator. Disposable P1 grade is fine.

Have a bundle of 60-80 litre (or approx. 900 mm wide 1200 mm deep) heavy duty plastic bags on hand.

If taking dirty filters back through food production areas, set up a ‘red-line’ and have a person working either side. The person on the ‘dirty’ side will pass the bagged dirty filter over the red-line to the person on the ‘clean’ side who will take the filter out through the plant.

Ensure the air moving fan is switched off – air flow will quickly circulate any dislodged dust, sending it to exactly where you don’t want it!

Remove the dirty air filter carefully, avoid jerky movements that will dislodge the dirt and make it air-borne. Sometimes the filter is stuck to a seal gasket so carefully lift this away from one corner and work your way around the filter slowly.

Place the dirty filter in a plastic bag and tie off the opening or use a cable tie or packing tape to completely seal off the opening.

Double bag the filter for extra protection – steel framed filters particularly can pierce one layer of plastic easily.

Dispose of filters and any disposable personal protective equipment immediately in an approved waste facility.

Clean and sanitise your work area after all of the dirty filters have been removed, bagged and disposed of.

Now you are good to commence fitting the new air filters.

If you need assistance or advice with the correct removal and disposal of old air filters, Presco Environmental Services have IAQ consultants and on-site service teams available to help you – call us on 0800 773 726 (0800 PRESCO) or email sales@presco.co.nz

Want more information? Contact our friendly team below: