The purpose of this ac duct cleaning method is to remove the inert suspended matter such as foreign objects, moulds etc. HVAC duct cleaning will be done until all suspended matter and loose debris are fully removed from the ducting system.
Following tools shall be arranged before starting the ac duct cleaning works of HVAC ducts:
- Cleaning Tools
- Vacuum Equipment and accessories
- Ladders/ scaffolding
- Manometer for air checking
- Air Compressor
- Retractable Fall Arrester System
- Safety Breathing apparatus
Shaft Preparation
In shafts and risers works are carried out over temporary working platforms which are installed at every floor level.
Separate safety emergency rescue plans and procedures are prepared for implementation during the ac duct cleaning activity.
Site supervisor safety supervisor shall check proper lighting and ventilation availability before starting the AC duct cleaning works.
Ladders / scaffolding to be secured firmly over the working platform and checked by competent person, prior to start of hvac duct cleaning work. Site Supervisors to keep check of working technicians in risers all in regular intervals.
AC Duct Cleaning Work Procedure
Prior to commencement of work, coordination will be done with contractors and people working on other services.
Ensure access panel are widely open for the inserting of tools some access panels can be used near VCD, Fire dampers, filter sections Horizontal duct works etc.
Conduct preinspections to determine exact location and type of AC equipment and if any more access points are required.
Ensure AC system is working and there is no abnormality of sound or noise before starting if there is a such unusual noise report shall be submitted to the building operation management or tenancy maintenance before conducting the cleaning in such report in case.
Close A/C system or isolate a section of ducting.
Place protection on furnishings or equipment below the areas.
Create negative pressure by using specialized vacuum equipment installed either inside the building with HEPA filtration or outside the building using the primary filtration or monster vac.
Remove grills / vents and plug openings except for the one farther away from the vacuum equipment.
From the vent / grill farther away, insert the selected cleaning tools use to loosen the dust dirt and debris, which shall be pulled away inside the ducts while working toward the vacuum containment equipment.
For longer horizontal distance ducts, tools for cleaning shall have extended arm to reach the point where to remove dust dirt’s and debris manually be sure no solid and sharp objects left before using the vacuum equipment.
Use Plastic sheeting on the ground while transferring or mixing cleaning chemicals unless required by specialist and manufacturers standard.
When sections of supply or return air ducts have been completed sanitizing shall be carried out using sanitizer.
Filters and grills, coils and drip tray shall be cleaned and sanitized.
For vertical and riser ducts locate the access door panels again use selected tools for cleaning and removing dirt dust and debris if found inside the duct works before using the vacuum equipment.
To access points and locations of access doors and panels use the chart and access door schedule installed on the ducting system in accordance with approved shop drawings and specifications.
For large ducts can acquire a person to go inside for cleaning but assuring the use of safety breathing apparatus and must have limited time duration 15-20 minutes to stay inside the ducts to avoid suffocation or incidental accident during cleaning aside from using SCBA an appropriate ventilation hoods must be placed inside the ducts access opening where the blower fan discharge an air inside the large ducts and after cleaning manually start using the vacuum equipment to suck all fumes left during cleaning.
Close access panel or access doors instantly after finishing the ac duct cleaning works.
Ensure all hvac duct systems are completely cleaned and must be supported and provided with signed reports. Inspection reports to be forwarded to the consultants and be witnessed by all relevant parties and to confirm compliance with testing & commissioning schedules.
Discover more from Method Statement HQ
Subscribe to get the latest posts sent to your email.