Total Air Care: Your HVAC hygiene package

When can this HVAC hygiene service help?

Total Air Care helps with the following problems:

  • Foreign matter and pathogens entering your factory
  • A blocked or overworked fan increasing power consumption
  • Excessive power being used to maintain negative or positive pressure in your factory
  • Sickness or poor health and wellbeing caused by bad breathing air

Total Air Care helps by:

  • taking a proactive approach to air quality
  • stopping any build-up of pathogens or foreign matter in your HVAC system
  • cleaning fans to make them more efficient and decrease your energy use.

Total Air Care will also help you comply with your building warrant of fitness (BWOF), customer and food safety standards, IRHACE, ASNZ3666.2 and any quality statements an overseas customer may have given you.

On this page:

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.


Te Kepa changing a filter as part of a Total Air Care HVAC hygiene service


So, what is Total Air Care?

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.

Our Total Air Care HVAC hygiene service is a complete end-to-end clean of your entire HVAC system.  All components of your HVAC system – from air intake to factory – will get dirty, harbour pathogens, and corrode.  We make it our business to ensure the air entering your factory is clean and carries none of those pathogens or dirt. 

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



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.  This report includes things like broken seals or door clips, floor condition and broken lighting (broken lighting attracts bugs).


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.


Recommendation of technologies that will assist in keeping your system hygienic year-round:

Our advisors can look at your system, and help you choose products that  will ensure it stays hygienic all year round. Some of these technologies include needlepoint bipolar ionisation (an air cleaning technology that  removes dirt and pathogens using ions) and anti-microbial coatings (a  special technology that can be painted inside your system to stop the growth of mould and fungi.


Water Cooling Tower Cleans

Technicians perform a deep clean to remove Legionella risk.  All our technicians have food safety understanding and experience, which is paramount when it comes to this clean – the risk of contracting listeria and other pathogens is high.  Compliance cleans are also completed, to meet AS/NZS 3666.

We have a unique standard operating procedure for cooling towers that includes a multi-stakeholder agreement.  This is the special requirements of every stakeholder – e.g the government, your factory, the tower manufacturer, the people who treat your water etc. – all put together into one process for our technicians to follow.  Our customers have found this extremely helpful and efficient as opposed to every stakeholder caring only about their individual needs that often conflict with those of other stakeholders.   Learn more about our water cooling tower cleaning here.


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 and certificates of completion (COCs) for factory records.



Our building maintenance division aids this Total Air Care service.  It allows our technicians to perform small maintenance jobs in your HVAC system, such as fitting a new hatch or popped rivets and repairing rust.


What are your alternatives?

You should use refrigeration engineers as well.
Refrigeration engineers will keep your whole air handling unit (AHU) working really well, and you need that.  However, these engineers are mostly focused on mechanical HVAC.  To keep your system compliant, you need someone with a hygiene focus as well.  This is us. 

Your factory workers can fix and clean your HVAC system.
Using your own workers to maintain your HVAC system is an option.  We advise you to be careful of the following points:

  • It is likely your workers do not understand how imperative precise sealing of your ducting is, therefore your ducts could have leaks.
  • Your factory workers are likely not confined space trained. This means they will not be able to clean inside your ducting. 
  • Your staff are likely trained to follow a process, and able to do this very well. We have seen factory workers do a great job at changing filters, yet miss important issues right there, because it was not in the process.  This is why we train our technicians to understand the system as a whole, and to keep a keen eye open for anything surrounding that could cause a problem, putting their hard work to waste. 

You could use reactive services rather than programmed work.
Using reactive services will help you put out fires as they arise.  However, it is likely this will be far more expensive than a scheduled maintenance program.  The cost of downtime and an urgent fix is higher than regular small maintenance. 

You can ask your filter supplier to clean your filters.
Often, filter suppliers will offer a cleaning service.  In the last 15 years of servicing HVAC systems, some of the worst maintenance we have come across was where the system had supposedly been maintained by the filter suppliers themselves.  This is because these companies are often under-resourced; changing filters is their priority, not cleaning – therefore the cleaning often gets neglected.  For HVAC hygiene, it is better to choose a service provider with a focus on hygiene. 


Frequently asked questions

Factory managers often ask us:

  • How long will my filters last?
  • How often should everything be changed?
  • How often should it be washed?
  • How often should my screens be backwashed?

The answer is always: it depends. 

It depends on what filters you use, and what environment they are in.  Heavily soiled filters are inefficient; it is always better to clean or change them before the last minute. 

With screens, the outside environment is a huge factor.  Things that can effect screens include nearby earthworks, carbon and exhaust fumes from a tanker bay, prevailing winds and the amount of rain and the direction it comes from – bacteria love damp places. 

Insect screens will need to be cleaned more regularly in summer.  More insects in this season mean the screens get clogged up faster. 

We are always happy to visit your site and give you a recommendation on filter cleaning and changing or perform a parallel audit to give you an indication of how your system measures up for audit compliance. 


How much does Total Air Care cost?

Generally, the price for our Total Air Care service is based on three things:

  1. Industrial cleaning supervisor: $692.46/day + GST
  2. Industrial cleaning technician: $590.49/day + GST
  3. Cost of filters

Read Matthew’s full break down of the cost of Total Air Care here: How Much Does Total Air Care Cost?


Do we have any limitations in this service?

Because of our focus on critical hygiene, we do not provide mechanical HVAC service – things like fan belts or heating and cooling components.  We also don’t provide electrical components and sensors.  You still need both of these things. 

We believe you should let the specialist take care of their specialty.  Don’t pay an electrician $100/hour to clean your ducting.  Don’t pay an HVAC engineer to change your filters.  Pay them for the skills they are an expert in. 

We will keep on perfecting our HVAC hygiene skills and you can use our technicians the industrial hygiene side of things. 

Lastly, we don’t do complete system replacements.  Please remember, new filters cannot fix a broken system. 


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


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0800 773 726
06 278 0712
PO Box 530, Hawera, 4610
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