Lately many people have been asking me about the difference between a portable system or a truck or van mounted vacuum and a POWER VACUUM TRUCK. So, I thought I would briefly describe the difference.
The difference between a duct cleaning job done with a power vacuum truck and a portable system is enormous. Contractors using inadequate vacuum collection systems and short cleaning procedures can cause more problems than they solve. According to the EPA-Environmental Protection Agency, these substandard jobs can release more dust, dirt and other contaminants into the air than simply leaving the ducts alone.
In order to complete the job correctly and according to NADCA standards, the contractor must place the system under negative pressure. This procedure is almost impossible to achieve with most portable vacuums which are rated under 4,000 cfms (cubic feet per minute). Even the largest portable vacuum, gas powered or electric, is only capable of 5,100 cfms, which is grossly inadequate. Some contractors attempt to deceive potential customers by stating they have a power vacuum truck, when in reality, they have mounted a portable system in the rear of a van or pick up truck. The fact is that an actual power vacuum truck (see photo) is an expensive investment (approximately $100,000) and most start up and fly by night companies simply don’t have the capital to invest in such equipment, so they purchase a tiny portable system for under $5,000 and call themselves duct cleaners. A portable system does not have the power to remove all the dirt and debris in the average home’s ductwork system.
Another important factor is that it is very common for portable systems to have maintenance problems. The seals and gaskets tend to deteriorate which then allows contaminants to reenter the living spaces in the home. Also HEPA filters must be frequently maintained and replaced or they lose their effectiveness. Either of these situations turn what was a bad health situation in the ductwork into a dangerous health situation in the home.