Ventilation Hygiene (Duct Cleaning)
There were issues of poor airflow within the building and the temperature set point was difficult to reach and then maintain. There had been external assistances where engineering changes had been made to the cooling system to increase the cooling capacity across the face of the coil in order to produce cooler air. TVH were contacted to provide advice of the systems performance. Upon inspection of the supply air ductwork, the air stream was found to be restricted due to turning vanes within the system were found to be dislodged and leaning up against another set of turning vanes within the supply air system.
The building is a single storey establishment which operates 24/7. The building is predominantly sealed and is solely reliant on the air conditioning system for air distribution within the occupied space. There is only one air conditioning plant located in a dedicated plant room. The air conditioning is a large Air Handling Plant serviced by a chilled water system. The return air and outside air intakes are ducted directly into the Air Handling Unit. The building is located in the Southern Australia Zone (BCA Zone 7).
In order to return the system back to full operational use the following items were undertaken;
- Total Ventilation Hygiene Pty Ltd (TVH) provides Heating Ventilation and Air Conditioning (HVAC) Mechanical Services along with Specialised Ventilation Hygiene Services nationaly, operating out of Brisbane, Darwin, Melbourne, Sydney, Regional New South Wales (Wagga Wagga and Tamworth), Perth, Port Hedland, Adelaide and Townsville.
- Cleaning of Air Handling Unit
- Removal of damaged turning vanes and installation of new turning vanes
- Duct Cleaning to the internals of the entire Supply Air Ducted System; Solid Ducts, Flexible Ducts, Cushion Boxes and Supply Air Diffusers.
The duct cleaning works were completed during night shift to minimise disruption to the operation of the building. The number of TVH staff on site was increased to reduce the total number of days that access to the system was required.
The dislodged turning vanes were removed and new ones installed into the correct position. Due to the amount of dust and debris located in the ductwork it was a requirement that all ductwork downstream of the turning vanes be cleaned. When there is restricted air flow the number of dead air zones within the supply air system increase and therefore allows dust, debris and other contaminates to enter the system. If the turning vanes had been reinstated without cleaning the likelihood of contaminates become airborne when the system was reinstated was almost certain.
It’s important when conducting any mould works within a building that it is conducted according to the IICRC S520 International Best Practise Guideline. Once a mould event (outbreak) has occurred it is important that all items with the space are remediated or a detail clean is conducted (dependant on the severity of contamination) to ensure that the entire space can be brought back to normal ecology, pre-existing conditions before the fungal activity.
This project was directly supervised by a NADCA Air System Cleaning Specialist and IICRC Certified Mould Remediator.
Flexible Duct Supply Air - Before
Flexible Duct Supply Air - After
Solid Supply Duct – Before
Solid Supply Duct – After
Solid Supply Air Duct – During Cleaning