Total Air Care: Your HVAC hygiene package

Indoor Air Quality control is critical for maintaining a bacteria free zone.  We bring a unique ‘hygiene’ approach to filter servicing, not the standard ‘mechanical’ approach common in the industry.

Presco Environmental technician, Frank, changing filters


Before you begin reading…


Being one of New Zealand’s world-class food producers, you will understand why HVAC hygiene is of the utmost importance. In case you would like a refresher, read this article.

Presco Environmental’s Total Air Care package thoroughly considers every aspect of HVAC hygiene. 


Presco Environmental's HVAC hygiene ABC


Condition Grade Assessment

The initial step in HVAC Hygiene where the system’s current state is graded against the standard. To identify issues, technicians use three tests; visual inspections, pressure drop readings across filters and ATP testing for cleanliness. Presco Environmental IAQ technicians then provide a condition report including a list of actions to correct any issues found.


Air Filter Selection, Supply, Installation and Bypass/Leak Tests

For each situation, technicians advise the best filter solution, always meeting ISO16890 standards. Presco Environmental supplies all types of air filters;

  • Insect screens
  • Primary course grade filters
  • Secondary pocket filters
  • Secondary compact filters
  • HEPA filters
  • Carbon filters
  • Grease filters
  • Reusable frame filters with disposable filter media
  • Washable filters


End-to-End Deep Clean of Filtered Air Supply Ventilation System

HVAC servicing should include not only regular filter changes at the correct intervals, but also a deep clean of all of the internal surfaces of the ventilation system downstream (clean air side) of your filter bank.

Technicians perform a chemical clean of the entire ventilation system, from outside air intake right through to supply air ceiling grilles. Repainting flaky paint, repairing rust damage and replacing leaking or damaged seals can all be done at this step. Any damaged or aging filter holding banks are repaired. The air supply fan should also receive a full clean.  This increases air movement efficiency; a dirty fan is less efficient as it requires more power to run and can cause vibration issues. HVAC components to be cleaned and sanitised include:

  • air intake louvres / plenum
  • filter holding banks and filter rooms
  • air supply fan and fan room
  • heat exchange coils
  • air supply ducting
  • air supply grilles / registers
  • condensate drain trays and pipes; clean and sanitise.

Following a HVAC system deep clean, antimicrobial coating can be applied to control mould regrowth.


End-to-End Clean of Extraction System

A deep clean and sanitise should be conducted of the:

  • grilles and registers: this will take place from inside the factory
  • grease filters, if fitted
  • internal ducts to remove product build-up
  • extraction fans to increase efficiency.


Supply and Install UV-C Lighting

Presco Environmental supply and install UV-C lighting systems.  These eliminate airborne pathogens and control odour. This is a particularly effective solution for hygiene of heat exchange coils.


Supply and Install Ozone Generation Equipment

Presco Environmental supply and install Ozone generation equipment.  This removes airborne pathogens and control odour.


Water Cooling Tower Cleans

Technicians perform a deep clean to remove Legionella risk.  Compliance cleans are also completed, to meet AS/NZS 3666. 


Scheduled Hygiene Maintenance Programs

Presco Environmental work with you to create ongoing or annual HVAC hygiene maintenance programs. These include scheduled checks and cleans of both the clean and dirty side of filters to ensure no bypass has occurred. These checks are based on IRHACE best practise guidelines. Technicians provide documented maintenance reports for factory records.


Want to check your own HVAC hygiene?

Here is a checklist of the 12 most common failures of HVAC system. While it is in no means conclusive, these steps help to prevent foreign matter entering your environment.

Download here: 12 Point Checklist for HVAC systems



“We are happy with the standard of work.  Communications are good, reporting/feedback is clear and accurate and comes in a timely manner.  Presco also has a good understanding around sensitivities regarding confidentiality and uses our own camera to take photos during checks rather than bringing in their own.”



Matthew Prestidge, General Manager

Got a question about HVAC hygiene?

Contact our senior Indoor Air Hygiene advisor, Matthew Prestidge, at matthew@presco.co.nz


Enquire or Book a job
0800 773 726
06 278 0712
PO Box 530, Hawera, 4610
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