Laser Engraving Machine:
Exhaust System Selection Guide
When you select a laser engraving machine, you must consider multiple
factors, including processing capabilities, software, ease of operation,
and ease of maintenance, among others. One item that is often overlooked
is cabinet exhaust and proper ventilation.
The laser in a laser engraving machine is a powerful processing tool,
capable of marking, engraving, and cutting a wide variety of materials.
Most materials have a by product of debris, odor, or both. Evacuation
of these by-products is important for several specific reasons:
Some of the fumes can be irritating to the lungs, nose, or eyes
making for an uncomfortable working environment.
Some of the out-gassing can actually be toxic to humans.
Certain materials create debris during processing that can be damaging
to the mechanics of system.
Unvented debris and fumes will adversely affect the optical components
within the system.
There are statewide, regional, and country-specific environmental
laws that require the capture of fumes and debris caused by many types
of processes, including lasing.
There are numbers of internal and external exhaust systems available.
The Gravograph LS100, LS100Ex,
and LS900 laser engraving machines have been
designed for efficient air flow and efficient exhausting. The LS Series
offers two internal exhaust methods as standard equipment. We refer
to them as 1) Head Exhaust (or Head Nozzle Exhaust) and 2) Back Exhaust
(or Rear Exhaust, Back Collector).
The Gravograph laser engraving machines have a unique feature
that allows quick selection between the two methods. It is a manually-actuated
slider valve, located inside the cabinet. Sliding this valve to the
left actuates the rear exhaust. Sliding to the right opens the head
Each has advantages and disadvantages based on the application. Regardless
of which method is used, control of the fumes when they exit the lasing
cabinet is crucial. Below is a diagram showing the two exhaust configurations:
Internal Exhaust System Differences
As stated above, each method has its own advantages and disadvantages,
however the basic distinction is the Static Pressure required for each
method to operate optimally. Static pressure is more related to the
size of the plumbing used to pull the air than to anything else. In
the case of the lasers, the LS100
has a 2" inlet for the rear exhaust and a 1" hose to the head.
The LS100Ex and LS900
laser engraving machines have a 4" inlet for the rear exhaust and
the same 1" hose at the head. As a result, the static pressure
requirement at the head is much higher than at the rear exhaust port.
LS100Ex & LS900 Laser Engraving Machines
||Static Pressure (H20)
So, as the chart is reviewed, the obvious conclusion is that the head
exhaust hose requires a significantly higher static pressure to create
enough suction to remove the fumes. This is caused by having to pull
a large volume of air through a relatively small hose. Though the CFM
is lower, the actual pressure through the tube is higher.
Exhaust Systems for Different Applications
Most applications, probably 80%+, can be addressed by using just the
rear exhaust. It provides a nice, even exhaust flow though the cabinet
and will remove most fumes and debris including wood smoke. The 4"
inlet pipe is in-line with the rear exhaust port, which is the width
of the cabinet.
The other 10% to 15% applications are better served by the head exhaust.
These are usually materials that create an excessive amount of smoke,
such as rubber, or have noxious fumes like many types of acrylic. The
theory behind the head exhaust is to keep the head as close as possible
to the actual lasing process, so it can collect the fumes as soon as
they are generated. Note: With some materials, it helps if the processing
speed can be lowered slightly, to give the head exhaust time to be effective.
Note: Due to the small cabinet on the LS100, the rear exhaust handles
nearly every possible application effectively.
Comparison Table of Exhaust Systems for GNH Laser Engraving Machines
Stand-alone Filtered Exh.
||This is a high CFM unit that is capable of providing
only the Low Static pressure needed for the system.
||This is the most common device sold with the lasers,
it provides enough "pull" to meet the High Static and
Low Static requirements of the system.
||Heavier duty unit, designed for high volume process
in harsher environments. Adequate for rear and head exhaust.
||The integrated option is a variation of the Level
3 product. It becomes the base of the laser thus the "integrated"
||Very high volume, relatively inexpensive, and small in size.
||The most flexible solution. Stands alone and can be relocated
easily. Optionally it can be wired for "On Demand" usage.
This unit is “No Odor" in most operations. With a custom
hose length, the unit can be located as far as 30ft from the laser.
||Industrial grade construction, easy filter change, fairly small
footprint and relatively quiet in operation (55dB).
||One power connection. Minimizes the floor space required. Meets
the High Static and Low Static specs. (Note: Not as efficient at
the head exhaust port).
||Requires remote mounting and requires outside venting due to having
||Decibel rating is 62dB, which is loud for a small shop. Too tall
to fit beneath the machine. Does vent hot air from below.
||Does not vent externally in standard operation. Too tall to fit
beneath the laser. Most expensive offering.
||Runs at dB level of 65, and cannot be placed remote to the laser.
It does vent air from below and thus should have some clearance
provided around it.
||Requires HVAC technician to install properly, including modifications
to the customer facility.
||Customer can self install, using the hose and clamps, provided
with the unit.
||Customer can self-install.
||The machine comes with a short exhaust hose for installation and
then it is simply plugged into the power source.
||Typical motor maintenance and periodic inspection for wear and
cleanliness is recommended.
||The side access door makes filter maintenance fast and simple.
The unit has multiple filters that have to be checked periodically.
The unit does have sensors that will indicate when there is an air
||Requires some disassembly for maintenance, but this is minimal.
Filters and hoses should be checked on a regular basis. For additional
charge, it can be configured with flow control sensors.
||There are three (3) filters that require replacement. These include
both an active carbon filter and a HEPA filter as well as an inline,
pre-filter. All hoses should be checked for clogging periodically.
||Filters require periodic replacement. Hoses should be cleaned
from time to time. In addition, there is a catch bag.
||Filters and catch bag must be periodically replaced. Hoses should
be cleaned per usage requirement.
||The three (3) filters are consumable and must be replaced as required.
||This unit vents (unfiltered) to the outside of the building and
such is subject to local air quality and environmental rules. It
is the end user's responsibility to determine is this type of system
is compliant to the local rules, codes and regulations.
||As a standard, this unit cannot be vented externally. Some low
level odor will be present during process, but there will be no
air born particulate left not captured.
||The unit is best suited for industrial applications and in facilities
that have high volume.
||The unit is fully self- contained, and the filters are easily
accessible. This unit cannot be vented outside, and such meets all
air quality standards. There will be some slight odor when processing
particularly noxious material.
Proper External Exhaust System Selection
As we established, an external exhaust system is required on every
system for several reasons. There are pros and cons to each that include
price, size, noise levels, and consumables. Gravograph offers
several different types of external exhaust systems. We refer to them
in the following terms:
Level 1 - Motor Blower Unit
HP 1.5 HP
Decibel Level 62 dBA
Level 2 – Stand-alone Filtered Exhaust: (General Purpose)
Air flow 480 m3/h - 282 CFM
Max pressure 90" W.C. 22 kPa
Motor (2) 1,0 kW
Voltage 110 V or 220 V
Dimensions 13 x 21 x 45 in H
330 x 540 x 1140 mm
Weight 138 lbs - 63kg
Optional Inlets 2, 3 , 4 inch diameter
50, 75, 100mm dia.
Optional Outlets 4" 6" or recirc. grill Decibel Level 62 dB at full
Suction hose included with clamps
Level 3 – Stand-alone, Filtered Exhaust System: (Industrial
CFM 270 CFM
HP 1.34 HP
Dimensions 18" x 19" x 42"H
Weight 121 lbs
Decibel Level 55dBa
Level 4 - Integrated, Filtered Exhaust System
Air flow 240 m3/h - 141 CFM
Static pressure 22 kPa
Motor Brushless 1,2 kW
Voltage 110 V or 220 V
Dimensions 37 x 28.3 x 20 in
940 x 720 x 505 mm
Weight 121 lbs - 55kg
Inlet 4 in - 100mm
Outlet 5 in - 125mm
Decibel Level 65 dB at full speed
Suction hose 100 mm – 4 in / 1 m
Exhaust pipe 125 mm – 5 in / 5 m
Gravograph Laser Engraving Machines
Gravograph Laser Engraving
LS100 Laser Engraver
LS100Ex Laser Engraver
LS900 Laser Engraver
If you have questions about any of the information above or would
like more information about purchasing a laser engraving machine, please