Many Central Vacuum systems on the market use some sort of cloth filter before the air and dirt enter the vacuum motor. Some vacuums such as the Beam, Eureka and many other central vacuum use these filters as the only filters to prevent the dirt and dust from getting sucked up into the motor. These filters have dead weights sewn into the center of the bag and in theory when the vacuum turns off, then the bag is supposed to drop down and shake the loose dirt off. This does not work well for two reasons: first; when the vacuum motor is turned off, the motor has momentum which slows it down over a period of time. While the motor is slowing down, the cloth bag which is supposed to drop down quickly, does not do so as it drops slowly while the motor slowly comes to a stop!!! Secondly, the fine dust particles which plug the pours of these cloth bags do not get released from the tiny pours in the bag. (The only way we have found to effectively clean these bags is to vacuum them with another vacuum!!!)
These bag type vacuums are usually designed to be a permanent cloth bag solution which cannot be replaced by the user, while some can be replaced by a technician, and others cannot be replaced at all. The problem with this type of filtration systems is that they eventually plug up and need to be cleaned or replaced as the pours of the cloth bag become plugged with fine dust, no longer allowing air to pass through them. If they are replaceable by the user, such as the CycloVac and AspirTech vacuum offer then these are user friendly. If they are a Beam or Eureka style permanent cloth “self cleaning” cloth filter, then these are not user friendly and this is why Grohovac Installations does not sell or recommend this type of vacuum!