In our industry, this topic arises almost every time we begin discussions with a new client. Can I use my dust collector to vacuum up debris on the floor or can I use my vacuum system to collect airborne particulate from a process? What is the difference between the two?
The answers are simple, and can reveal ways that you can save money by applying the correct technology to specific applications. In the discipline of industrial ventilation there are two specific types of air moving systems, each designed for specific tasks. Several key differences between a dust collector and a vacuum system are essential for optimizing your process. Below is an overview of the critical differences.
What is a Vacuum System?
Industrial Vacuum Cleaners function on the basic principle of low volume, high pressure. (LVHP). Think about your small home vacuum, or shop-vacuum that cleans your car. The intake velocity is up to three times higher (up to 10,000 FPM) for industrial applications. This requires an air mover with close mechanical tolerances. Collection hoses are typically 1.5 inch to 2-inch diameter by twenty-five to fifty-feet long. The air volume required for each user in this scenario is about 123 SCFM. This is referred to as a low volume high pressure (LVHP) system.
Housekeeping debris is vacuumed from floors, walls, around equipment, and from bulk piles under conveyors and transfer points. A vacuum system with these characteristics, installed as a central system, typically consumes five to seven horsepower per user. Generally, a vacuum system picks up dust via an operator tool such as a dusting brush, and transports it through a small diameter hose to the air/material receiver separator. The small hose increases the pressure drop to about one inch of water column per foot of hose. This small diameter somewhat inhibits how much material can move at one time.
The power requirements of the vacuum system depend on the total system effect loss. The longer the piping system, the more differential the pump must overcome to maintain the pick-up velocity. This is why in a central vacuum system you have multiple drops. It reduces the distance for the hose, and thus can maintain powerful pick up velocities. Therefore, in central vacuum systems with multiple drops the factor that drives cost is how many users the system will support. The more simultaneous users, the greater the differential pressure and produces lower pick up velocity. Vacuum systems are perfect for precision cleaning applications commonly dealt with in regular housekeeping.
What is a Dust Collector?
A dust collector differs from a vacuum system in three important ways: configuration, airflow, and effect.
The configuration of a dust collector is a series of parts that operate in tandem to produce safe TLV or PEL (Threshold Limit Values as designated ACGIH or Permissible Exposure Limit for OSHA). The basic system consists of a capture hood, an air mover, duct-work, and intake and exhaust ducting.
These systems vary depending on the needs of the client, the spacing of the facility, and the type of dust being collected.
The dust collection system is a high volume, low pressure (HVLP) design. This means that the collector is slowly (1500 to 4000 FPM) in-taking large amounts of airborne particulate, across large cross-sectional areas.
Specialized Source Capture Hood for Silica Dusts
Compare the small area of a vacuum hose that causes high pressure due to the narrow diameter of a hose or vacuum cleaning tool to a dust collection hood. A dust collector in-takes the contaminated air across source capture hoods, some of which can be as large as 20 feet wide by 20 feet high, or in-take ductwork throughout a facility which could encompass specific operations or assembly areas.
The dust collector (HVLP) can handle air quantities far exceeding anything a vacuum (LVHP) can handle. Simply put, vacuum systems are for precision cleaning and material conveyance, whereas a dust collector maintains breathable air and clean process air throughout an entire facility.
Click the photo for a case study on dust collection
Tied closely with the previous point, a dust collector handles airborne particulates and dust in a different approach than a vacuum system. The dust collector can be facility wide, or a portable unit or downdraft/backdraft table. For details on these types of systems, and how they differ from one another, read our article on dust collectors vs. downdraft tables here. Again remember, the general rule is vacuum systems handle precision (high pressure, low volume) and dust collectors generally the opposite (high volume, low pressure).
How They Differ?
After this brief review, it is easy to see the differences between the two systems. A Vacuum is High-Pressure, Low-Volume and a Dust Collector is a Low-Pressure, High Volume. Vacuums are used mainly for precision cleaning and material conveyance, and dust collectors for full scale facility or process filtration.
It is understandable to conflate the two because a user is typically not trained in the application of these systems.
If you have any further questions, consider viewing our FAQ page. Or if you have specific questions, feel free to contact our engineers to discuss your challenge and learn how Air Dynamics can help solve your challenge.