negative air duct cleaning equipment Drawbacks
The goal of most air duct cleaning contractors is to remove the accumulated dirt, debris and other contaminates found in the HVAC system. This is called source removal. The HVAC system includes the supply ductwork and plenum, return ductwork and plenum, grilles/registers, and the furnace or air handler – basically everything in the air steam.
The primary short comings of the Rotobrush system
The primary short comings of the Rotobrush system is its inability to put the ductwork under proper negative pressure or power air wip system that RamAir air duct cleaning equipment has. Putting the ductwork under proper negative pressure is important so the dirt, debris and other contaminates that are dislodged via brushing does not escape through the cracks and seams of the ductwork into the home or buildings occupied space. In parts of the country with high humidity, proper negative pressure is especially important to prevent any microbial (mold, mildew, etc) contamination in the HVAC system from escaping into the home or building space.
If you look at traditional HVAC system cleaning equipment, they consist of a vacuum collection system, air compressor, and cleaning tools (brushes/air washing/whips, HEPA vacuums, etc). The vacuum collection system is connected to the ductwork or plenum and puts all or a portion (with zoning) of the ductwork under negative pressure. Then using the cleaning and agitation tools the dirt, debris and other contaminates are dislodged from the inside of the ductwork. The light particles are sucked out via suction from the vacuum collector and any heavy particles fall to the bottom of the ductwork. Then you would push any remaining particles toward the vacuum collector with air washing tools. The suction or negative pressure from the vacuum collection system also keeps the dirt, debris and other contaminates from escaping through those cracks and seams in the ductwork.
The Rotobrush system does not create enough negative pressure
The Rotobrush system does not create enough negative pressure in the ductwork. The vacuum is located in the center of their brush. As the brush spins and dislodges the dirt and debris it is throwing that dirt debris and other contaminates forward, backward, right and left. The suction of the vacuum will pick up the dirt that is close to it but is not strong enough to pick up all the dirt that has been thrown forward, backwards, right and left. That “thrown” dirt can escape into the home or building space through the cracks and seams of the ductwork and/or it can continue to lie in the bottom of ductwork waiting to be removed. In round ductwork the loosen dirt and debris falls or is funneled to the bottom of the duct where the vacuum pick up is but there is still dirt and debris in front and behind the brush head/vacuum pick up. In square and rectangular ductwork the dirt and debris is not funneled anywhere so the vacuum will pick up even less of the dirt and debris. The larger the duct the more dirt and debris is left behind.
Another shortcoming of the Rotobrush system is that it doesn’t include any cleaning tools
Another shortcoming of the Rotobrush system is that it doesn’t include any cleaning tools or the capability to clean a furnace/air handler or coil sections in an HVAC system. Remember, the goal of most air duct cleaning contractors is to remove the accumulated dirt, debris and other contaminates found in the entire HVAC system (all the componenets). If you clean just the ductwork and then turn the HVAC system back on, the dirt in the furnace/air handler/coil sections will soon be spread into the supply ductwork contaminating what you have just cleaned. Rotobrush offers other products for dryer vent cleaning, insulation handling and inspecting but nothing for cleaning the heart of the HVAC system (furnance/airhandler/coil section).
The inability to provide adequate negative pressure and the inability to clean the entire HVAC system are the two primary shortcomings of the Rotobrush air duct cleaning system and others like it. Before investing your hard earned money into air duct cleaning equipment/tools be sure you have a good understand of its capability and any shortcomings.