How to Choose a Dust Collector
N.R. Murphy Limited strives to provide the right product for each individual application. We always encourage to begin your dust collection project by asking the experts, and letting us find you the perfect solution.
What Dust Collector is Right for Me?
N.R. Murphy Limited strives to provide the right product for each individual application. We always encourage to begin your dust collection project by asking the experts, and letting us find you the perfect solution.
Determine your system requirements
In order to determine which dust collector is right for you, you first need to assess your system needs. To start, create a list of dust producing equipment and map them out over a facility layout. Most equipment manuals will provide a recommended C.F.M. (Cubic feet per minute) requirement. If no recommendation is given, you can estimate based off the pickup port size off our technical handbook below (please note these values are estimates only) you must choose a velocity that will keep the material suspended in the duct work (woodworking for example is typically 4,000 F.P.M. feet per minute).


Decide where to locate the dust collector
Next you must determine where you intend to position the dust collector. It’s important to note that there are often more restrictions on indoor collectors. For example, the National Fire Code of Canada restricts the size of indoor collectors to 1,000 C.F.M. and the National Fire Protection Association allows enclosure-less dust collectors of up to 5,000 C.F.M. indoors (with restrictions). Using the scaled drawing of the facility, lay out the ducting so that each piece of machinery is connected through branch lines – to the main duct. Using these measurements, you can calculate the static pressure of the total system. A typical system with medium length duct runs will be approximately 12″ – 14″ wg.
The Bag vs Cartridge Debate
One of the major decisions you will have to make will be whether you will opt for a filter bag (sock) style system, or filter cartridge style system. For most dust applications we recommend filter bags as they are considerably less likely to clog and maintain performance over a longer filter lifespan. You can also adjust the filter bag diameter if your dust particles are smaller, in order to increase filter media efficiency and reduce the physical size of the collector. We know a lot of manufacturers that ONLY sell cartridge style, or recommend it for almost any application. We believe that cartridge filters should only be used in fume or extremely miniscule dust particle applications. In our experience cartridges quickly clog when the dust is large (such as wood dust) which greatly affects performance and filter lifespan. Cartridges are useful when the particle size is small as it can maximize the filter media surface area to reduce the overall size of the collector required. Some manufacturers will recommend an overbag over the cartridge, the introduction of an overbag on cartridges effectively reduces the filter area to the area of the overbag and allows only the finest particles to penetrade past and into the cartridge. The problem here is that once inside, the finer particulate cannot be pulsed back out because of the accumulated particulate on the overbag. If the cartridge style is right for your application, we recommend reviewing our C-Series/Cartridge style collectors.
Other Dust/Filter Considerations
Other considerations to make regarding your dust application and filtration include:
Does the dust have explosive properties? If so you will want to consider various explosion relief and safety accessories. Not sure if your dust is explosive? We can help have it tested.
Is the dust/waste long and stringy? You may want to consider prefiltering with a cyclone, using a material handling fan fitted with cutting knives or increasing the filter bag diameter.
Is the material overly abrasive (ie. fibreglass insulation)? You may want to consider heavy-duty filter cuffs and heavy-duty rotary air lock wipers. We can even supply pre-filtering cyclones made with AR400 steel.
Is the material particularly toxic? You may want to consider secondary filtration units like HEPA filters. We can help supply HEPA housing units within the return ducting.

Shaker Style vs Pulse Jet Style
Shaker style and pulse jet style are the two different varieties of dust collectors N.R. Murphy Limited supplies. Their names are references in how their filter bags are cleaned, but they each have their own pros and cons for each facility.
Shaker Style
This variety of dust collector uses a separate small motor to shake the filter bags clean upon shutdown of the main collector unit. This is accomplished through a timer board located in the provided control panel. This style of dust collector is a more cost-effective solution, but is limited in that the collector should be shutdown periodically (ideally around every 4ish hours, so during a lunch break and at the end of the shift). If your facility only runs a single shift or can shutdown regularly then we would recommend a shaker style dust collector.
Pulse Jet Style
This variety of dust collector uses compressed air to pulse clean air through the filter bags during operation. This is accomplished through a pulse board that will sequence how often and long to pulse compressed air. This style of dust collector is a premium solution designed to run 24/7 and is ideal for large facilities and systems. This style does require compressed air, and typically has a bit more maintenance involved. If your facility runs 24/7 or would like to keep that option open, then we would recommend a pulse jet style dust collector.

Who is involved in your process? What code compliancy will you be requiring?
Are you applying for permits? Will you be required to follow certain codes? Will you be involving engineers? Your insurance company? We at N.R. Murphy Limited can arrange professional engineering services for turn-key solutions or can spec solutions to meet various codes including NFPA compliancy.
Are you a woodworking facility wanting to return the air?
Returning the filtered air back into your facility is a common and beneficial element of a dust collection system. It can reduce heating costs in the wintertime and maintain pressure within your facility (otherwise you may need a makeup air unit). For a lot of applications (ie. woodworking) you will be required to utilize an abort damper and spark detection system. These work in tandem to protect your facility, workers, and equipment. While an added expense, it often pays back their cost with savings in heating.

Waste Removal Options
How you decide to remove your waste will come down to your facility, employee preferences, volume of waste, and area available. With a wide variety of manual budget friendly options, to advanced multi-equipment set up that can facilitate extreme high volumes of waste without having to shutdown – N.R. Murphy Limited can provide you a wide variety of waste removal options for your dust collector.
Plastic Refuse Bags
Drums
Drum Lifting Rack
Shortened Drums
Waste Bin
Self Dumping Hopper
Rotary Air Lock
Transfer Fan to Trailer
Transfer Fan to Bin
Screw Conveyor

Serviceability
Your dust collector will last a long time, and over the years you will be required to change filters, fan belts and perform other various maintenance procedures. A caged ladder and platform add-on package makes service work considerably easier, especially for our taller models. We can offer various custom packages to allow for easier access to the filter access door, top mounted fan, and other various accessories like the Abort Damper. We can also include ladder shields or access ports in the hopper section as additional options.
Noise concerns?
Like all industrial equipment, and especially ducting conveying high velocity generating significant vibrations, your dust collector will create a certain amount of noise during operation. We always recommend utilizing a duct silencer and oversizing the return duct line to slow down the air. Furthermore, for top mounted fans we can include an acoustical enclosure which will significantly reduce the noise outside. If noise is REALLY a concern, let us know as we have several other options at our disposal that we’ve utilized in past specialty cases.

High Temp? Low Temp? We do it all.
Our equipment operates in and is built to survive Alaskan winters and the Mali-Saharan desert. We can offer high-temp construction grade if the processing air is hot. If freezing and condensation is an extreme concern, we can offer a premium heat traced exterior.



The Importance of Ducting
While we pride ourselves on our equipment, the dust collection system will only be as good as the ducting. It’s important to spend the time properly planning, designing and installing a quality system. Plastic flexible ducting is easy to install, but generates 10x the static pressure of the same length of spiral ducting. Transitions need to be mathematically calculated to ensure proper velocities across the entire system. If this sounds overly meticulous or outside of your comfort zone contact us and we will either be able to assist you with planning your layout with your new collector, or connect you with one of our installers across our North American network.