Guess How Much Bacteria Just Entered Your Factory!

Saskia Prestidge
December 12, 2020

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

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

Picture this.

The air outside carries 200-1500 bacteria per m3.
An air conditioning system has a capacity of 10,000m3/h.
This means it can bring 2-15 million bacteria into your factory, every hour.

What a way to contaminate food & beverage production.

Scary stuff!

But what about air filters?

Air filters capture a percentage of the particulate matter in the air that passes through them. Only a percentage.

Particulate matter includes things like dust, soot, smoke, pollen, mould, bacteria.

And that is assuming the filter frames and supply air ducts have no leaks. Leaks will let 100% of that particulate matter through!

So what happens to the percentage that is not trapped in the filters?  

It passes through to the clean side of your air filters, travels on through your ventilation system, and ends inside your clean factory environment.

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

A clogged condenser coil

 But, that does not take away from the fact that this particulate matter is:

  • building up in your HVAC system
  • clogging condenser fins
  • creating bacteria colonies around heat exchanges, and
  • contaminating supply air duct work.

You must remove the accumulated foreign matter and sanitise the surfaces. If this is not done, sooner or later you are going to have issues with the air quality in your factory.

What is the answer?

A documented, annual hygiene schedule for your ventilation system is the solution. This will compliment the mechanical servicing and filter replacement programs you already have in place.

This is not usually a task undertaken by factory operators or refrigeration engineers. Look for a reliable ventilation hygiene contractor. They need 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, and
  • air diffuser grilles.

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

This depends on:

  • the environment outside your factory, and
  • the standard of air quality required inside your factory. 

The best answer is to engage an indoor air quality 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!