Commercial Services

Duct Doctor Raleigh subscribes to the basic concept of source removal duct cleaning, and therefore does not recommend the introduction of chemicals of any kind into the air distribution system. The EPA and the National Institute of Safety and Health (NIOSH) are skeptical of the claims made by manufacturers of anti-microbial and duct sealants.

Equipment and Workmanship

Commercial Duct Cleaning Process – Duct Doctor Raleigh.
If the vacuum unit is to be located inside the building the vacuum system shall pull at least 6000 CFM and shall use a filtration system that incorporates HEPA filtration as a final filter. IF the vacuum unit is to be located outside the building it shall be a truck mounted unit pulling at least 8,000 to 10,000 CFM. The compartments shall be dust tight. Air compressor must produce a minimum of 175 PSI at 17.5 CFM. All work shall be accomplished by workmen trained and skilled in HVAC system cleaning.

Ductwork Cleaning

Duct Doctor Raleigh – Commercial Ductwork Cleaning Information– Ductwork shall be cleaned by inserting a vacuum hose in one end of the duct or trunk line and, with a Reverse Air Jet Nozzle, brush all interior surface areas of the duct system including reheaters, joints, seams, splitters turning vanes, scoops, baffles, cracks and crevices otherwise inaccessible. As the RJA Nozzle is operating, the residue shall be drawn into the vacuum unit (minimum 6000 CFM). All foreign materials such as dust, mold, soot, lint, hair, bacteria, and other air movement residue shall be removed from the ductwork interior, and will be cleaned to meet NADCA Standard 1992-01.

Duct Access Opening

Access openings shall be provided at required points of the duct system for physical and mechanical entry. These openings shall be provided as required at points adjacent to turning vanes, dampers, and other obstructions that might tend to trap or entrain dust, dirt, lint, and debris. Duct access openings shall be constructed in accordance with SMACNA HVAC Duct Construction Standards.

Interior Lining

Duct Doctor Raleigh takes special care with ducts that have interior lining materials. A light vacuum process shall be used to prevent damage to air side surfaces. All loose fibrous materials shall be removed by a combination of controlled forced air and combined vacuum power method.

Grills and Registers

All grills, registers, and diffusers shall be cleaned with a non-toxic, disinfecting solution. Areas around registers shall be lightly cleaned by blowing with air. After cleaning, adjust all registers to insure proper air flow.

Coil Cleaning

Coils shall be cleaned using a non-acid coil cleaner sprayed onto the coil and forced into the coil using air pressure, then flushed out using a pressure washer. There shall be no residue of the coil cleaner left in the system.


Fan shall be cleaned by using 200 PSI air pressure and an air nozzle designed for that purpose. Each blade of the fan shall be cleaned individually using care not to disturb any balancing weights.


Any areas in the ducts that are found to have visible microbial growth will be painted using an anti-microbial paint in an area two (2) feet in either direction of the growth. Paint shall be applied in accordance with manufacturer’s specifications using an airless sprayer or paint roller, whichever is more practical for the location. No painting will be done without prior approval of the owner representative.

Visual Inspection

Upon complete inspection of each section, notify inspector for visual inspection. Upon acceptance by inspector seal with silicon caulking and neatly patch with galvanized sheet metal the same gauge as the ductwork.

Duct Doctor Raleigh for all your Duct Inspection needs!

Area Clean Up

Commercial Duct Cleaning Professional Service – Every precaution shall be taken to prevent the spread of dust and dirt in occupied areas. All desks, computers, and work tables shall be covered with drop cloths while work is performed in that area. A complete area clean-up after each work cycle shall be performed and no debris left behind.

Surface Cleaning

After the system has been cleaned and restarted, the entire work area shall be cleaned of any dust and debris. The ceilings will be lightly brushed to remove any loose dust, walls will be wiped or brushed, furniture will be dusted, and carpet and upholstered furniture will be vacuumed to remove any debris that has been circulated by the HVAC system prior to cleaning.


Sealants and encapsulates cannot be substituted for visible contaminant removal.