Information on vacuum cleaner selection and dust categories
Why choose a wet/dry vacuum cleaner or a high performance
industrial vacuum cleaner?
Dust and dirt are always present.
Vacuum cleaners are an aid for daily cleaning and in
production areas. They are indispensable for improving
working conditions and for ensuring that quality standards
are met. The production of dust and dirt is inevitable in
manufacturing and processing operations. Larger dust
particles quickly settle, fine dust particles float for
extended periods in the breathable air and are inhaled deeply
into the lungs, where they are deposited. Over time, dust
compromises health and/or the quality of production results.
Differences in equipment:
Equipment design: Can be monoblock - mobile or
static - or split into multiple components.
Filter unit: Multi-stage filter, cartridge filter,
plate filter, etc.
Dust class: Also for hazardous dusts in dust
classes M, H (more details can be found at the end of
Explosion protection: Vacuum cleaners according to
design 1 (B1)
Motor power: Well constructed motors from 1.5 to
13 kW. These vacuum cleaners can also be used to reliably
operate small central vacuum systems as well as large
pipework systems up to 300 m long.
Separation: Pre-filters serve to protect the main
filter. Downstream filters are preserved by preventing
them from coming into contact with hot materials and
liquids. In addition, they also make it easier to dispose
of larger quantities.
Mobile waste containers with or without lifting
mechanism, hinged bottom, BigBag, tilting tray etc.
Duty cycle: 2 - 3 hours (single phase ) powered
machines - up to 24 hours (three phase) machines.
(Examples, where a guarantee of completeness is not provided,
uses for hazardous substances must be considered on
Observe potential hazards!
General rules: If a source of danger (e.g. vacuuming of
solvents, chemicals, asbestos, aluminium, wood dust etc.) is,
or has been recognised, this must be taken into consideration
when selecting a suitable industrial vacuum cleaner.
Compliance with ATEX regulations and ATEX zoning will have
been established after carrying out risk assessment.
Vacuuming of predominantly fine dust:
Choose a vacuum which is not too powerful, but has a large
filter surface area (unless it is for dust with a high
specific weight, such as metal dust etc.). Note: Consider
hose length. The filtering efficiency of the filter must be
taken into consideration, so that the vacuum cleaner collects
dust without releasing significant amounts back into the
environment. Is the dust hazardous to health? If yes, then
choose an absolute filter (HEPA). Is the dust explosive? If
yes, then choose a B1 vacuum cleaner, displaying an EX
Vacuuming a mixture of fine dust and larger particles:
Same as for vacuuming fine dust, but choose a vacuum with a
mechanical pre-filter (cyclone) to prevent damage to the
filter. Select a more powerful vacuum cleaner with a large
filter surface area. The large filter surface area is
necessary in order to prevent premature saturation of the
filter, which in turn maintains consistent vacuum power.
Guidelines for dust classes M, H and B1 should be observed
here as well.
Vacuuming of predominantly large particles:
Select a more powerful vacuum cleaner with higher collection
Pre-filtration is not nearly as important for this type of
use. The power of the device should be adapted to suit the
diameter of the hose, length of the hose and type of material
being vacuumed. A standard device is usually sufficient. If
the device will be used in a potentially explosive
environment, it is also important to observe B1 (ATEX).
Customer would like to vacuum predominantly neutral
Predominantly neutral or thicker liquids, sludge (typically
water based liquids): Choose an NT vacuum cleaner. Consider
the quantity of material to be vacuumed. Select appropriate
disposal system: A tilting chassis or attachment of a
drainage hose may be advisable, as well as the installation
of a pump. Does the liquid expand (turn into foam)? Use a
Small amounts of dust can also be vacuumed with these vacuum
Customer would like to vacuum liquids mixed with chemicals
(milder cleaning agents):
The selection of a device with a stainless steel container is
recommended in most cases. For corrosive media, the behaviour
of the medium must be precisely analysed and consideration
given to requirements that will be put on the device.
Customer would like to vacuum oil or cutting fluid which
Vacuums suitable for swarf collection are required to be
fitted with integrated cyclone plates to separate swarf from
liquid for vacuuming CNC machine heads, drills or cutting
Normal wet/dry vacuum cleaners will be overburdened if used
to vacuum these materials, as the atomisation properties of
the liquids are different than those of water. Vacuum
cleaners for shavings are fitted with a different type of
inlet, in order to better control atomisation of the liquids.
Customer would like to vacuum material in a potentially explosive environment created by gases or fumes:
For safety reasons, a compressed air vacuum cleaner (with
ATEX) is recommended in most cases.
However, each specific case should always taken into
consideration. The examples provided here are only to be
used as a reference!
There are also a few types of dust (e.g. extremely fine
aluminium and magnesium dusts, petrol etc.) which can be
problematic. These can also be removed with GS-tested
vacuums, but only under certain conditions.
It is important to understand that high wattage alone will
not yield the highest performance. The right ratio of vacuum
pressure to airflow is critical.
A high airflow rate means higher speed of the material being
Higher vacuum pressure is required for vacuuming heavier
materials and for vacuuming from extended heights (e.g. down
Furthermore, the diameter of the hose also has a critical
effect on the vacuum cleaner's air flow/vacuum pressure
ratio. The hose sizes which are supplied as standard are in
the medium/average range, which in most cases will ensure
good performance of the vacuum, yet not interfere with the
passage of materials through the hose and into the
The use of a well proportioned primary filter is necessary
to ensure consistently good vacuuming capacity. Pre-filters
can reduce strain on the primary filter. In order to keep
exhaust air as clean as possible, absolute filters HEPA (in
dust class H) can be installed downstream if necessary.
Until 1997 (with a transitional period through 06/2002),
national directive ZH 1/487 from the German Federal Centre of
Accident Prevention was the applicable law for the
classification of dust classes, and thus the basis for safe
removal of materials and dust. This national regulation has
been replaced by EU standard EN 60335-2-69. This regulation
is applicable for all of Europe.
The category of use is defined according to level of risk to
health and the explosive potential of a dust:
The WEL level is also taken into consideration: The
WEL limit specifies the maximum Workplace
Exposure Limit. The lower the WEL limit, the
more hazardous the dust is. (Note: The term WEL has replaced
the previously used term MWC - Max. Workplace
Additional information about materials and dusts, as well as
classifications of machines to be cleaned of dust, can be
obtained from the Health & Safety Executive (HSE).
according to EN 60335-2-69
dusts with max. workplace exposure limit (WEL) > 1