The objective of source removal duct cleaning is the removal of all dirt, debris, and other contaminants from the duct work. This is recognized as the only acceptable form of cleaning and decontaminating of air duct systems. Absolute Environmental utilizes several different types of source removal methods, because not all systems are structurally the same.
A conventional HVAC duct system consists of a supply system of ducts to carry heated or cooled air from the furnace/air conditioner (air handler) to various parts of the home or building, and a return duct system to bring air back to be heated or cooled again. The supply network consists of a main duct that carries air to smaller branches for delivery to the desired locations. The return network works in reverse. Different systems require different cleaning methods.
Portable Power Vac Method - Preferred method for houses, villas, townhomes, and light commercial jobs. The powerful air movement (approximately 4,500 cubic feet per minute) pulls throughout the entire air duct system drawing all contaminates towards the portable vacuum (the house stays clean). This method enables our technicians to remove contaminants from all parts of the system, regardless of the location. Cleans areas where no roto-brush equipment can.
The air conditioning unit is turned off.
An access hole is cut into the supply plenum, and the flex duct from the Portable Power Vac inlet is connected to the plenum. The Portable Power Vac is then turned on to create negative pressure within the supply duct work. (The Accessibility or configuration of duct work and or AHU may change the point of suction line hook up. Alternate hook-up points may include hook-up at main vent on the system, AHU cabinet, or access hole in plenum).
All of the vent covers are removed and cleaned.
Foam core boards are placed up to the supply vent openings. The air movement holds these boards up to the openings. This also increases the air movement in the ducts. All but one supply vent is covered. The open supply vent allows for the air to safely flow backward through the air duct system, without creating adverse negative pressure.
Starting from the furthest vent opening, each branch line is cleaned using nylon duct brushes, cable driven brushes, or forward air blast assemblies to loosen debris. The agitation tool causes debris to be quickly caught up in the air movement from the Portable Power Vac and is carried out of the system into the Portable Power Vac’s vast holding tank outside. The process is then repeated at each vent opening. Once all the branch lines have been cleaned, the main trunk line is cleaned.
After the dust and debris is removed from the system, an E.P.A.-registered product called Oxine is lightly fogged throughout the air duct system. The air movement from the Portable Power Vac pulls the Oxine throughout the system. This product immediately kills fungus and bacteria that may be left in the system, and then evaporates, leaving no residual chemical activity. If left in a jar, Oxine will break down to simple sodium chloride (common table salt).
The Portable Power Vac is turned off.
The air return is manually cleaned with portable vacuum equipment. It is then decontaminated with Oxine.
The plenum area above the air handler unit is manually cleaned with the portable vacuum equipment. It is then decontaminated with Oxine.
The access opening is securely closed. If the system is sheet metal, the proper gauge sheet metal is cut to size. Insulation is put in place if required. Mastic is applied to the patch opening. The patch is secured with sheet metal screws, duct tape, metal tape, and more mastic. If the system is made of duct board or flex duct, the ten-inch cut-out is reinserted. The entire area is fastened with approved duct tape and metal tape to insure a proper seal.
The insulation in the air handler unit case is manually cleaned and then treated with Oxine to kill any residual mold, fungus, or bacteria. The blower motor is inspected and cleaned, if necessary and accessible.
The vent covers are re-installed.
The system is turned back on and inspected for proper airflow.
The air return is measured for a custom-made air filter. The filter size will be noted on the contract, and may be purchased at the customer’s discretion. Good filters are an investment for your duct-cleaning job. High quality filtration is the key to keeping your air conditioning equipment and duct system clean and protected for the future.