Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/1179928
Healthy Indoors | 19 High Volume Air Cleaning: Pneumatic cleaning utilizing substantially greater pressurized air volumes than convention- al air whips and duct balls, typically 50--100 CFM at 125-150 psi. Due to the massive air flows required to operate these high-volume tools, large tow-behind diesel or electric rotary screw compressors are required. These devices include blast nozzles and air snakes that can self-propel over 100 feet into ductwork. The snakes clean via a combination of physical con- tact between the blast head and duct interior, and a constant flow of high-volume pressurized air. This technology is quite aggressive and is best suited for unlined metal duct systems. Robotic Duct Cleaning: Although this technology has been around for quite some time (we were using it back in 1991), it still has a bit of a new-age mystique in the industry. This may be due, in part, to the hefty price tags associated with acquiring one of these machines. Not unlike the story of "Goldilocks", duct robots come in a variety of sizes, from tiny inspection-type units all the way up to large ones that can take the place of a crawling technician in many cases. Video Inspection/ First Person View (FPV) Systems: In- ability of cleaning technicians to actually see what they're do- ing has been an age-old problem in the duct cleaning industry. Often, "cleaning" remote portions of the ductwork ended up coming down to guessing when it was sufficiently done (Hey, it looks good from my house...). The potential flaws with these ter all, duct cleaning is likely being done to improve, not degrade the indoor environment for occupants! Brushing and Whipping and Blowing...Oh, My! There are literally a ton of techniques used in the indus- try to dislodge debris from duct surfaces and drive them to a collection vacuum. Let's take a look at a few of the commonly used ones: Rotary Brushes: These consist of systems that uti- lize a variety of interchangeable brush heads that are spun via a motorized cable drive or a pneumatic head to scrub attached debris off duct interiors. Air Whips/Duct Balls: Rubber or poly tentacles and/or machined blast heads that are attached to high pressure pneumatic lines to clean duct interiors by physically strik- ing and blasting surfaces. These tools typically require 15+ CFM of air pressurized from 125-225 psi to operate. The aggressiveness of the cleaning can be controlled by regulating the pressure of the supply air to the tools. Contact Hand Vacuuming: As the name implies, this is the most basic (and very effective) cleaning method in which technicians manually vacuum off the interiors of HVAC components with brush attachments connected to small HEPA vacuums via long hoses.