In virtually every industry in the US, where air quality and worker well-being are crucial to the success of any business, industrial dust collection systems play an important role. These systems ensure smooth operations and employee safety. But, choosing the right components while staying on budget can be a complex puzzle. Let’s simplify this process, finding the sweet spot between wise investments and smart savings, all while building powerful and sustainable industrial dust collection systems.

5 Key Factors When Budgeting for Your Dust Collection System

1. Dust Properties: The Foundation for Filters and Collectors

Before diving into budget details, remember that dust properties set the stage. Understanding these properties guides filter media and collector choices, ensuring top-notch functionality.

Think About These Dust Properties:

  • Size: Are the dust particles small or large?
  • Density: Is the dust light, like wood dust, or heavy, like fine steel dust?
  • Chemistry: Does the dust have abrasive or corrosive qualities?
  • Temperature: Is your work area hot?
  • Moisture: Is there moisture or oil in the dust?

Knowing these dust properties helps you choose the perfect collector for your specific needs. Read more: Top 4 Reasons Why Baghouse Filters Fail.

2. Space Constraints: Finding the Right Size

Space limits define your collector’s size. These systems come in various heights, widths, and depths. Measuring the space and considering top-loading designs, which need overhead clearance for maintenance, are essential. It is also worth considering if you have an existing concrete pad, or if one must be poured to support the weight of your collector and fan. Watch the video: Intro Guide to Sizing and Design Your Baghouse.

3. Emissions Requirements: Navigating Legal Waters

Specific emissions regulations might apply based on your application. Emission limits differ by state and are expressed as efficiency percentages for cartridge collectors or emission limits (like lbs/hr or gr/dscf) for baghouses. These limits may impact the filter media required for your system, as well as the need for after-filters or additional equipemnt. Read more about regulatory requirements and compliance.

4. Volume: Sizing for Efficiency

Accurate airflow measurement is crucial for effective dust collection. Wrong volumes can disrupt production, air quality, and increase energy costs. 

Airflow is measured in cubic feet per minute (CFM), showing how much air moves per minute from a space.

Variables for Volume Calculation:

  • Dust collection method
  • Duct size
  • Workspace volume

Getting the airflow right ensures long-term collector efficiency. Want to know more? Read the following article: Why You Need to Properly Size Your Baghouse System.

5. Air-to-Cloth Ratio: Striking the Balance

The air-to-cloth ratio measures airflow efficiency through filter media. The right balance ensures optimal filtration.

Why Air-to-Cloth Ratio Matters:

  • Lower ratio for efficient dust removal
  • Higher ratio leads to increased energy costs and decreased suction

Calculating this ratio helps size the collector accurately, preventing pressure drops and maintaining air velocity. How to Select the Right Differential Pressure for My System?

Baghouse Styles: Picking Your System

The three most common baghouse styles are pulse jet, reverse air, and shaker style. Each has its advantages and disadvantages. The right choice depends on factors like space, maintenance needs, and filtration requirements.

  • Pulse Jet: Bags cleaned while operating, low maintenance, flexible sizing.
  • Reverse Air: Gentle cleaning, divided sections, custom bag design.
  • Shaker Style: Easy operation, low initial cost, shaker mechanism for cleaning.

Dust Collector Design for Easy Maintenance

Choosing design features that simplify maintenance is a smart long-term investment. Things to look for:

  • On-demand filter cleaning for efficiency and durability (not all control panels offer this option)
  • Modular design for expansion and accessibility
  • Quick access filter covers
  • Standard filter sizes for cost-effective replacements

Combustible Dust Safety Equipment

Safety is top priority, especially with combustible dust, and there are specific equipment requirements for systems handling combustible dust. To ensure your system is safe and compliant, take the following steps:

Tailored Dust Collection Design

Each dust collection application is unique, needing a comprehensive approach. Partnering with an experienced dust collection design and engineering companies like, ensures efficient and effective systems designed for your facility.

In conclusion, budgeting for industrial dust collection systems goes beyond finances. It’s an investment in health, safety, and efficiency. By considering dust properties, space, emissions, volume, and air-to-cloth ratio, while prioritizing maintenance and safety, you can build a system that’s cost-effective and high-performing. Remember, a well-designed system not only saves money but also ensures a cleaner, safer, and more productive work environment.


Contact Us to Speak to One of Our Baghouse Experts.


For more baghouse related training and information, be sure to check out our Baghouse Online Training page.

You’ve invested in high-efficiency equipment and tools for your industry, but is your dust extraction system working at peak efficiency or is there waste in your system – wasted time, efficiency, or cost? In this article, we’ll explore the most common mistakes when designing dust extraction and collection systems and how to avoid them. A well-designed system not only ensures a clean and safe workspace but also maximizes the lifespan of your equipment.

Mistake #1: Incorrect Duct Diameters

Mistake: Using duct diameters that are either too small or excessively large can lead to problems. Undersize diameter ducts can quickly become clogged, or wear prematurely due to excess dust velocity. Oversize ducts reduce airflow velocity, which may lead to dust settling and clogging up your system.

Solution: Calculate the appropriate duct diameter based on your system’s needs to maintain optimal performance. You should know the minimum carrying velocity of your dust type, and pick a duct size to match the required air flow (CFM) for your dust. If you need assistance sizing your system, please watch this video Watch the video: Intro Guide to Sizing and Design Your Baghouse.

dust carrying velocity chart

  • Start by understanding the required velocity for your dust and the CFM – then pick a duct diameter to match.

Mistake #2: Using Straight Tees

Mistake: Installing equal (straight) tees can lead to clogs, especially when dealing with soft and fine dust particles. These sharp corners cause turbulent flow, resulting in static pressure loss, and areas of low flow where dust will pile up and clog your system.

Duct union examples

The tee joint on the right is very inefficient; the 45-degree union fitting on the right is a much better design.

Solution: Opt for reducing tees, Y-pieces, or lateral tees to ensure smoother airflow and prevent clogging.

Mistake #3: Using Short Radius Elbows

Mistake: Using short radius elbows can disrupt airflow and greatly increase static pressure drop, similar to the tee joints mentioned above.

sharp 90 degree duct elbow

This sharp elbow will result in a large static pressure drop.

Solution: Use larger radius elbows (1.5D is standard) to maintain smooth airflow throughout your system and ensure you have adequate static pressure at your pickups.

Mistake #4: Accumulating Fittings Near Equipment

Mistake: Placing elements like dampers, bends, tees, and reducers too close to equipment can hinder proper airflow and reduce system efficiency. Remember, velocity is key in keeping dust airborne – disruptions in airflow slow down the dust, and your system must expend energy to speed it back up after a sharp elbow, etc. If that elbow is right next to your pickup, there is insufficient “runway” to gain sufficient velocity and laminar airflow – resulting in uneven or reduced suction at your pickups!

Solution: Maintain a minimum distance of 2.5 times the nominal duct diameter between airflow-disrupting elements and your pickups to ensure the system operates efficiently (even better is to remove or reduce these elements altogether!)

Mistake #5: Overuse of Flexible Ducting/Hoses

Mistake: Flex hose is very convenient and easy to install, and is often used to connect the last few feet of ductwork to your pickups. However, they are extremely “expensive” in terms of static pressure loss. Excessive use of flex hose can create unnecessary airflow resistance (up to 3X that of a standard duct), significantly reducing system efficiency.

Standard flex hose

Standard flex hose

Solution: Limit the use of flexible hoses to the absolute minimum required.

Mistake #6: Using Incorrect Duct Materials:

Mistake: Choosing the wrong material for your duct system (like plastic pipes instead of steel) can be dangerous and lead to explosion risks, very early wear and failure, and other issues.

Rolled lip steel duct

Rolled lip, clamp-together steel duct is standard for dust collection systems.

Solution: Prioritize safety by using metal duct with smooth inner walls to minimize resistance and ensure unhindered airflow. When in doubt, contact an expert to size and select ductwork for your dust collection system.

Mistake #7: Excessively Long Duct Runs

Mistake: Designing excessively long duct runs results in large static pressure drops across the system, meaning that the suction your fan generates isn’t available where it’s needed at the pickups. It’s all being lost in resistance across the long duct segments.

Solution: Install shorter main ducts with lateral discharge branches to individual machines for improved airflow and better static pressure where you need it.

Mistake #8: Incorrect Use of Gates and Dampers:

Manual cut-off gate

Manual cut-off gates are useful, but should be used in alignment with your system design.

Mistake: Incorrectly using cut-offs (also referred to as blast gates or dampers) in your system can lead to system imbalances (too much/too little air flow and velocity where you needed) and dust accumulation and blockages, as well as incorrect static pressure at your pickups.

Solution: If you plan to use manual gates to control flow (to turn specific equipment on/off, for example) ensure that is taken into account in the system design. Modifying your dust collection system then periodically “balancing” it to correct issues, although commonly practiced, is very inefficient and will result in sub-optimal efficiency. Generally blast gates should be fully open or fully closed. If balancing is required, contact an expert to help you with your system.


Contact Us to Speak to One of Our Baghouse Experts.


For more baghouse related training and information, be sure to check out our Baghouse Online Training page.

What is a Cyclone Dust Collector?

A cyclone dust collector (also referred to as a cyclone separator or simply a cyclone) is a device that is used to remove particulate matter from air or gas streams. It works on the principle of centrifugal force, which is generated by a rapidly rotating cylindrical chamber.

 Unlike a standard dust collector or baghouse that uses filters to collect dust from the air, allowing clean air to pass through, a cyclone dust collector uses centrifugal force and the  momentum of the dust-laden air to pull out heavier dust from the air stream. They are particularly effective for removing larger or non-uniform particles (strips and of wood, etc.) that might clog a cartridge or baghouse collector.

How Does a Cyclone Dust Collector Work?

Cyclone Dust CollectorHere’s how a cyclone dust collector works:

  1. Dust-laden air or gas enters the cyclone dust collector through an inlet and is directed into a cylindrical chamber.
  2. The chamber is designed to cause the incoming air or gas to spin around its axis. This creates a centrifugal force, causing the heavier particles to move towards the outer walls of the chamber and eventually drop out and settle at the bottom of the collector.
  3. The clean air or gas then exits the collector through an outlet located at the top of the chamber.
  4. The collected particles are collected in a hopper at the bottom of the collector, where they are typically discharged into a bin or other dust discharge method.

Animated GIF of a dust in a cyclone separator

When is a Cyclone Separator Needed?

Cyclone dust collectors and baghouse dust collectors are both effective at capturing and removing dust particles from industrial processes, but they are best suited for different applications.

Cyclone dust collectors are typically used for applications that generate large volumes of coarse and heavy dust particles, such as sawdust, wood chips, metal shavings, or granular materials. Cyclones are effective at removing these large particles due to their use of centrifugal force, which causes the particles to be separated from the air stream and collected in a hopper or bin. Cyclones are also relatively simple to operate and maintain, with low maintenance requirements and operating costs.

Baghouse dust collectors, on the other hand, are best suited for applications that generate large volumes of fine and light dust particles, such as welding fumes, chemical dusts, or pharmaceutical powders. Baghouses use a series of fabric filter bags or cartridges to capture the dust particles as they pass through the system. Baghouses are effective at capturing these fine particles due to their high filtration efficiency, which can exceed 99%.

In general, cyclone dust collectors are preferred over baghouse dust collectors for applications where the dust particles are relatively large and heavy, and where the process generates high volumes of material. Baghouse dust collectors are preferred for applications where the dust particles are fine and light, and where high filtration efficiency is required.

Often, a cyclone separator is installed in front (upstream) of a baghouse or other dust collector. The cyclone to remove the heaviest dust particles and the dust collector catches the finer dust. This has the benefit of lowering the dust load on the collector and removing large, sticky, or high-temperature particles before the dust-laden air reaches the collector, improving efficiency and filter life and avoiding the clogging of filters with large dust particles.

Cyclone separator upstream of a baghouse.

Cyclone dust collector upstream of a baghouse dust collector.

However, it is important to consider the static pressure loss of adding a cyclone separator into the air stream as it will increase the required load on the system fan.

It is important to consider the specific requirements of each application when selecting a dust collector to ensure that the system will provide effective dust collection while minimizing operating and maintenance costs.

Are There Different Types of Cyclone Collectors?

Yes, there are different types of cyclone dust collectors, each designed to suit specific applications and operating conditions. Here are a few variations of cyclone dust collectors:

  1. Single-cyclone dust collectors: This is the most basic and common type of cyclone dust collector. It consists of a single cyclonic chamber where the dust-laden air enters and undergoes centrifugal separation. The heavier particles settle at the bottom of the collector, while the cleaned air is discharged.
  2. Multiple-cyclone dust collectors: In this configuration, several cyclone chambers are arranged in parallel or series to achieve higher collection efficiencies. Multiple cyclones increase the surface area available for particle separation, improving the overall dust collection efficiency.
  3. High-efficiency cyclones: These cyclone dust collectors are designed with enhanced geometries and optimized airflow patterns to achieve higher separation efficiencies. They often incorporate modifications such as tapered inlets, vortex finders, and secondary air injection to enhance particle separation and reduce pressure drops.
  4. Reverse-flow cyclones: Reverse-flow cyclones, also known as reverse-flow dust collectors, operate in a reverse flow direction compared to traditional cyclones. The clean air is directed upward through the cyclone chamber, while the dust particles are collected in a downward flow. Reverse-flow cyclones are particularly useful in applications where the collected material is sticky or prone to re-entrainment.
  5. High-temperature cyclones: These cyclone dust collectors are specifically designed to handle high-temperature applications, such as those found in industrial processes involving hot gases or exhaust streams. High-temperature cyclones are constructed with materials that can withstand elevated temperatures and are equipped with proper insulation and cooling mechanisms.


Interested in Purchasing a Cyclone Dust Collector?

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An image of Baghouse expert Dominick DalSanto in front of a camera with the text "Sizing Your Baghouse" displayed in front of him
A video introduction to the Guide for Sizing and Designing your Dust Collection System

Hi, and welcome to our guide for how to properly size and design your dust collection system.

This guide is going to help you to avoid some of the more common pitfalls we see with sizing a dust collection system. For example, many dust collector OEM’s and sales rep organizations will frequently undersize their systems in order to beat the lowest price in any bidding competition. But then later on, once installed, they don’t perform adequately.

Our guide’s going to help you to calculate the approximate size and determine an adequate system configuration that will meet your application and process needs, which you can then use when comparing quotes from various manufacturers. Our guide’s also going to provide information that will be helpful for general baghouse maintenance, operation, as well as safety procedures.

If you have any questions, please, feel free to contact us for more information.

In this design guide we have reviewed a relatively simple baghouse dust collection system with few variables. Even at this level it is still recommend to consult with an experienced dust collector OEM like before making any equipment purchase. There may be additional factors to consider before determining the final sizing, design, construction and installation of a dust collection system.

Common Additional Considerations

  • Recirculating air back into facility
  • Balancing system with blast gates
  • Combustible and toxic dust
  • Filter styles
  • Dust discharge (manual or automatic)
  • Option for VRD fans

Recirculating Air Back Into The Facility

Recirculating air from the dust collector exhaust can prove practical in areas with cold climates to conserve heat. Make sure to include a ambient air return line to balance the airflows and prevent carbon monoxide poisoning. Additionally, any return duct needs to be sizes at least 2 inches larger than the main duct entrance and its SP added to the system total. Additionally, OSHA and other applicable safety regulatory bodies require any recirculated air to pass through a HEPA after filter.



Combustible Dust and/or Toxic Compounds Hazards

Many types of dust, including many woods are toxic, so take special care to choose a filtering system that will provide optimal safety. Facilities that handle combustible dusts must take special precautions to avoid potentially serious safety hazards from forming within their dust collection system. The National Fire Code issued by the NFPA (National Fire Protection Agency), OSHA combustible dust emphasis program, and the OSHA General Duty Clause and many other similar local and state regulations now require a combination of explosion/fire prevention and/or protection devices for any dust collection system handling combustible dusts. Prevention devices include spark arrestors, abort gates, high-speed sprinklers, inert gas or injection systems, and more. Protection devices include explosion vents, high-speed sprinklers and dry extinguishing injection systems. Fire experts should be consulted for any system potentially handling combustible dusts.

Filter Styles

Pleated Filters - Top and Bottom Load

New filter styles such as pleated filter elements can improve operation, reliability and collection efficiency while also lower operating costs (less compressed air to clean, last longer) compared to traditional bag and cage technology. They also allow for much smaller units (thus cheaper to build) while still having better air to cloth ratios compared to bags since they also provide more filter cloth in a smaller area.

Bags, cartridges or pleated filter elements are three common filter styles used in baghouse dust collectors. Cartridges are rarely used in new systems except for a handful of OEMs due to high cost and difficulty sourcing replacements. Bags and cages are the most versatile being able to work in the widest range of applications including temperatures up to 500F. In newer systems, pleated filter elements (sometimes called pleated filters) provide a much larger filter cloth area in a smaller space compared to bags (usually 3 times as much filter in half the space). They are widely manufactured and are only marginally more expensive than bag and cages. In addition, they provide superior performance, require less cleaning energy (i.e. compressed air) and provide less pressure drop over a longer service life. And due to their smaller size, collector units can be made smaller. (See our case study showing benefits of converting from bag/cage technology to pleated filter elements)

Best Practices to Increase efficiency and Reduce Size

Try to capture dust as close as possible to source to reduce size requirements. More directed venting better solution than venting large area as volumes increase rapidly when venting entire spaces e.g. Venting one machine at 600 CFM = 6 bag unit vs. venting entire room of 30’ x 30’ x 10’ = 9,000 cubic feet of air = 125 bag unit @ 3:1 ratio Oversizing for future expansion Good idea to size in additional 10% capacity for later. Minimal added costs upfront to add additional capacity, resizing later much more expensive (10:1 ratio roughly)

Balancing System Using Blast Gates

Blast gates should be installed on all branch lines to maintain system balance. Their proper use should also be part of regular training for dust collector operation.

Clean Out Traps

If your system has areas where long slivers of material could possibly hang-up and cause a clog, install a clean-out near that area.

Determining Required Capacity For Secondary Sources

6 baghouse hopper dust discharge styles

Various options exist for disposing of dust from the baghouse hopper. Here are 6 discharge methods

After adding all primary lines together determine how much extra capacity you want to install for secondary lines. If secondary branches are run sparingly then its possible to not include them in the calculation. When they need to be used you can divert some of the capacity from the primary branches (by shutting them down and blocking those ducts using a damper valve). Be realistic when calculating your needs and size appropriately.

Consider Variable Frequency Drive (VFD) Fans

VFD fans allow for more control over system performance and potential energy savings when loads constantly change.

Dust Discharge Options

The most basic discharge is a manual slide gate, that is activated manually by personnel. If dust loads are light or the system is infrequently used this may be the most economical option. However, failure to keep the baghouse hopper clean and result in major operational problems and damage the filters. Another option is for a rotary airlock that automatically cleans the hopper. This eliminates the need for a technician to manually clean the hopper, but comes at a price tag in the $2,000 – $3,000 range.

Ready To Size Your Dust Collection System?

Thank you for reading our online guide to sizing your dust collection system. After considering this information should be able to estimate what size dust collection system your facility needs. With this information in hand you can begin the bidding process for your new system. experts are ready to help if you have any questions. Please feel free to call at (702) 848-3990, contact us via our online form, or visit our resources section for more helpful dust collector information.

Need Help Designing Your Baghouse System?

Looking for help designing your dust collection system? Let our us use our 40+ years of expertise to help you select the right system for your application.


 Baghouse Design Guide Overview

Example of a dust collection system layout for a woodworking shop.

We continue from our last article where we reviewed the 4 key design variables of airflow (in CFM), static pressure/resistance, air velocity and air to cloth ratio. Now we can begin calculating these variables for our new dust collection system. When we are finished we will know exactly how large of a baghouse we will need (including how much filter area required) along with our fan output (x airflow @ y static pressure).

The sizing and design process can be divided into two stages. The first stage involves sizing your duct work for adequate volume (CFM) and velocity (ft/m) for the type of dust you will be handling. Then in the second phase you calculate the static pressure (SP) of your system to determine the size of your baghouse (how many filters and what size) and power of your system fan. If you already have a ductwork system and want simply to replace an existing baghouse/fan combo, you still need to calculate the CFM and static resistance from the existing ductwork system to properly size the baghouse and/or fan.

Need Help Designing Your Baghouse?

Looking for help designing your dust collection system? Let our us use our 40+ years of expertise to help you select the right system for your application.

Step 1 – Find the Minimum Conveying Velocity (ft/m) of Your Product

Determine from a reputable source the minimum conveying velocity for the material the system will handle. The box on the right lists several common materials and their recommend conveying velocities. Most materials require between 3,500 ft/m to 5,000 ft/m. A more extensive list can be found on

Step 2 – Identify Total Number of Primary and Secondary Sources

Sizing your system requires you to determine how many much airflow you need at each location. Begin by making a list of all the equipment you plan to vent with the dust collection system. Identify your primary and secondary sources that you will connect to the system.

Primary Sources need constant venting whenever system is running. Some facilities may have only one large source to vent (e.g. a single boiler, furnace, etc.). Others may have many different systems but each one requires its own system as the different equipment cannot be connected for some reason (e.g. gypsum plants, cement plants, process applications)

Secondary Sources do not always run concurrently without primary sources and sometimes shutdown completely. Secondary sources are common in wood/metal milling, fabrication and manufacturing shops. For example, a woodworking shop uses several different pieces of equipment such as saws, lathes and sanders requiring dust collection. While the large saw and lathe run continuously everyday (primary), a small specialty-use sander and a planner are only used once or twice a week (secondary) and never at the same time as each other. In this example, you would size your system to handle the two primary sources (saw and lathe) and only one of the two secondary sources (sander and planer) as they will never run at the same time. Plan with the objective of defining the heaviest use scenario so you can size your system to meet it. Incorporating pickup points that see limited or infrequent use may result in an oversized the system, which increases its total cost to purchase, operate and maintain. Plan wisely, as increasing capacity post installation is nearly impossible. A good rule of thumb is to oversize the system by roughly 10% to ensure proper operation and accommodate any future expansions.

Primary or Secondary Source?

  • Take care to correctly classify each piece of equipment
  • Classifying all sources as primary sources will result in an unnecessarily large system, increasing initial installation costs and making it more costly to operate in the long run.
  • Classifying too many sources as secondary sources will result in an undersized system, resulting in insufficient capacity for normal operations. This will produce production bottlenecks or inadequate venting leading to health/safety hazards.[/box]

Step 3 – Calculate Total CFM Required for Each Branch

In the next step, determine how much CFM you need at each branch of your system. If your source equipment has a built in collar or port identify the diameter (if rectangular calculate the total cross sectional of the duct and convert to round equivalent). On larger sources such as kilns, furnaces or process equipment or for sources with custom-designed venting determine CFM required by consulting with the equipment OEM or by using industry-best practice methods. (Consult a dust collection expert experienced in the specific application for advice.) Finally, using the chart in this section find your duct size and match to column with the required conveying velocity to find the needed CFM for each branch.

Determining CFM for Each Branch in Our Example System – To illustrate we have prepared a sample system layout for consideration of this design step (See illustration below. We will continue to use this same example throughout the following 3 sections.)

Here we have a woodworking shop with a total of (5) pickup points. We have a sander, backdraft table, planer and two floor pickups. Next we determine the CFM required for each branch by duct diameter and then matching it to the appropriate conveying velocity required for wood (see chart in previous section)

  • (1) Sander = 4” OD @ 4,000 ft/m = 350 CFM (rounded)
  • (1)Planer = 5” OD @ 4,000 ft/m = 550 CFM (rounded)
  • (1)Backdraft table = 6” OD @ 4,000 ft/m = 780 CFM (rounded)
  • (2) Floor pickups = 4” OD @ 4,500 ft/m = 400 CFM (For reference only, secondary sources are not counted towards final total.) Expert Tips Many types of equipment come with built-in connections for dust collection. These ports are sized by the manufacturer to provide sufficient ventilation while operating the equipment. Simply confirm the diameter of the port to calculate the required CFM (using chart in this section) for the unit.

Step 4 – Create a System Layout and Size Your Main Trunk

Now we need to create a layout of the ductwork system, deciding where it will connect to each machine and where we will place the dust collector. This will determine what size ducts we need including our main trunk line. To help illustrate these concepts we will continue to refer to our sample system first described in the previous section.

Steps to Layout Your System and Size Your Main Trunk

  1. Make rough floor plan showing the location of each piece of equipment
  2. Sketch layout of ductwork connecting each piece of equipment together and running all the way back to the dust collector
  3. Where two primary branches meet combine the CFM require by each branch (using figures from previous step) and calculate the duct size needed to provide sufficient CFM for both branches at the required air velocity (where needed round up to next largest duct size)

Example of a dust collection system layout for a woodworking shop.

Make Floor Plan of Equipment – Take your primary and secondary sources and make a rough floor plan of every piece of equipment. Once you have every source in its approximate location map out the ductwork connection each piece back to the collector. Try to locate your dust collector in a central, convenient location. Safety regulations covering applications involving combustible dusts (e.g. wood, metals, grains, etc.) may mandate placing the baghouse outside or on an exterior wall (along with explosion venting to the outside).

Create Rough Layout of Ductwork System – Now each piece of equipment needs to be connected together and run back to the baghouse. Start at the source farthest away from your collector. Using the CFM requirements you calculated for each branch in the previous step, note the diameter of the duct required and map it out running towards the collector to the point where the next branch connects. Additionally, note the length of each run of duct (important for next step).

Where the next branch connects add the CFM of both lines together and determine what size duct you need for that amount of CFM at the required velocity in ft/m. Increase the size of the duct accordingly and continue mapping the trunk forward. Repeat the process and increase the duct size only at each spot where a primary source connects to the main trunk. Continuing mapping your main trunk (making sure to connect to all primary and secondary sources) until you reach the collector.

Example of a dust collection system layout for a woodworking shop.

Sample shop layout – Notice our calculations for the required CFM, air velocity and the total static resistance generated by the system. Now you can determine the required filter area (i.e. number of filters in the collector) and the fan power. 

Determining Duct Size for Each Branch and Main Trunk in Our Example System – First, we begin with the farthest source the sander. Its built in connection port is 4”, so we begin with a 4” duct leading out of it. Then we continue running it where it connects with the 5” duct coming from the planer. (NOTE We do not increase the size where it meets the Floor Pickup, as this is a secondary source.) By combining 4” duct requiring 350 CFM and the 5” duct requiring 550 CFM, we get 900 CFM +/- at 4,000 ft/m (see previous section for more details). Where these two combine we need a duct to handle at least 900 CFM@ 4,000 ft/m. According to our chart, this falls between a 6” and 7” duct. Per best practice, we will move up and oversize the duct slightly to ensure sufficient airflow and allow for possible expansion later.

Continuing on the 7” duct next combines with the 6” duct running from the backdraft table. The 6” duct requires 780 CFM +/- and the 7” duct requires 1068 CFM. Again, the total combined CFM falls in between the 9” and 10” OD duct, so we size up to 10”. Finally, with all the primary sources connected, the system requires at least 1,680 CFM @ 4,000 ft/m.

Now we have sufficient CFM for all of our primary branches. We also have a safe amount of oversizing to ensure adequate operation and provide a cushion for any possible future expansion. To accommodate the other secondary branches we can install blast gates on all the branches and close off other lines. Expert Tips:

  1.  Try to keep the largest equipment closest to where you will place your dust collector.
  2. Try to run your ductwork in the shortest possible route.
  3. Always size up if the required CFM falls between two duct sizes. This allows for future expansion.
  4. Only increase the duct size when a primary source branch connects, but do not forget to run trunk so that all the secondary sources can connect as well.
  5. Consult fire/safety regulations may require the dust collector be located on an external wall or outside.[/box]

Need Help Designing Your Baghouse?

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Step 5 – Calculate The Static Pressure (i.e. Static Resistance) of Your System

Static pressure or static resistance (measured in inches of water w.g.) refers to the amount of resistance to airflow created friction and channeling of air through the ductwork. For the system to work the system fan must overcome the resistance created by the ductwork and the baghouse. Accurately calculating the static pressure or SP of the system is crucial for the system to function correctly. To determine the total SP of your system you must add the SP generated by following three elements together:

  • The branch with the great SP (also known as the Worst Branch)
  • The SP of the main trunk line, including any fire protection/prevention devices
  • The resistance created by the dust collector(s). This would include any precleaners (cyclones, knockout chambers, etc.) as well as the filters within the baghouse.

Calculate the SP of all your branches and identify the one with the greatest amount of resistance in w.g. (Likely the branch farthest from the unit with have the highest SP, but not always.) Only figure the SP of the worse branch into your calculations for the entire system’s SP. Next, move on to the main trunk line. Calculate the resistance created by the duct diameter and the length of each section, along with any elbows, splits, or other connections. Finally, identify the SP generated by the dust collector(s), which in most cases will be only a baghouse. For most baghouses plan on a maximum of 5”-7” of resistance (most baghouses should run between 3”-5” differential pressure, but sizing slightly above this figure is conservative and allows for some flexibility).

Steps to Calculate System Static Pressure (i.e. Static Resistance)

  1. Identify the branch with the highest static pressure (Worst Branch)
  2. Calculate the SP of the main trunk line
  3. Determine SP of dust collector

Determining Static Pressure for Each Branch, Main Trunk and The Baghouse in Our Example System

Step 1 – Find the Branch with the Highest SP – Starting at each piece of equipment work back through to the main trunk and determine the total SP of each branch. In our example, the sander branch has the great resistance.

  • Entry loss at equipment adaptor of 1.5” (constant)
  • 10’ of 4”OD duct
    • Reference Table 2-3 shows 100’ of 4” OD duct @ 4,000 ft/m = 7.03”
    • 10’ = 7.03 x .1 (for 10’ feet out of 100’) = 0.70” SP
  • (1) 90° elbow
    • Reference Table 2-4 shows (1) 90° elbow of 4” OD is equivalent of 6’ of straight pipe
    • 6’ of 4 OD = 0.28” SP
  • 25’ of 4” OD duct
    • Reference Table 2-3 shows 100’ of 4” OD duct @ 4,000 ft/m = 7.03”
    • 25’ = 7.03 x .25 (for 25’ feet out of 100’) = 1.76” SP
    • 1.5” + 0.70” + 0.28” + 1.76” = 4.24” Total SP for sander branch

Step 2 – Calculate SP of Main Trunk Line – In our example our ductwork has 50’ of 7” OD duct, followed by 30’ of 10” OD duct at 4,000 ft/m.

  • 50’ of 7” OD duct
    • Reference Table 2-3 shows 100’ of 7” OD duct @ 4,000 ft/m = 3.55”
    • 50’ = 3.55 x .5 (for 50’ feet out of 100’) = 1.78” SP
  • 30’ of 10” OD duct
    • Reference Table 2-3 shows 100’ of 10” OD duct @ 4,000 ft/m = 2.30”
    • 30’ = 2.30 x .3 (for 30’ feet out of 100’) = 0.69” SP
  • 1.78” + 0.69” = 2.47” SP Total SP for main trunk line

Step 3 – Calculate SP for Dust Collector – Each type of dust collectors generates different SP. For this figure, it is best to consult with an experienced baghouse OEM such as For our example we will assume a SP of 6” for a baghouse dust collector. Note: Baghouses are normally designed to operate between 3” – 5” of differential pressure. recommends being conservative with this estimate and designing in extra capacity to provide a cushion for normal operational ups and downs.

  • 6” Total SP for baghouse

Total SP for our example system:

  • 4.24” for worst branch
  • 2.47” for main trunk line
  • 6” for baghouse
  • = 12.71” total system SP

Now we have all the data needed for completing our system. The dust collection system must provide a minimum airflow of 1,680 CFM through a 10” trunk duct at air velocity 4,000 ft/m with a static pressure of at least 12.71” w.g.

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Next Section – Part 4 – Additional Considerations for Dust Collection System Design

 Baghouse Design Guide Overview dust collector technical Drawings - S-TA 9-144 Models

For a dust collection system to function adequately engineers must design and operate the system to maintain the (4) key design parameters of airflow (measured in CFM), airflow velocity (measured in FPM), Static Pressure/Static Resistance and Air to Cloth Ratio (or A/C). Changes to any of these key system parameters will result in systemwide performance issues. All four of these parameters are fluid and directly affect the others. Maintaining all at proper levels requires careful engineering, operation and maintenance. Lets review these four parameters one by one.

Airflow in CFM (Cubic Feet per Minute)

CFM – What Is it? – How much air the system moves is measured in Cubic Feet per Minute or CFM. (Related terms include ACFM for Actual Cubic Feet per Minute and SCFM for Standard Cubic Feet per Minute). Most often baghouses are sized and categorized according to CFM. In general, the larger the space being vented or the greater the number of pickup points in the system the more CFM required. The CFM generated by the system fan can be fixed or adjusted (Variable Frequency Drive or VFD Fans). However, total CFM generated by a fan can be affected changes in altitude, ductwork restrictions and sizing as well as resistance to flow created by the system (ductwork + filters).

Why Important? – Without sufficient CFM the sources will not be vented adequately. Poor venting directly causes damage to equipment, high emissions, loss of reclaimed product and hazardous environment (especially of concern in facilities handling combustible dusts or hazardous materials). Low CFM can also negatively affect air velocity, air to cloth ratio, and vacuum pressure, other key design parameters.

Vacuum Pressure (Suction) & Static Pressure (Static Resistance)

What Are Static Pressure and Static Resistance? – Vacuum pressure or suction is measured in inches of water gauge, w.g. and is the basis of a properly functioning dust collection system. The system fan must supply enough suction to pull the materials from the collection point(s) all the way through the ductwork to the baghouse and then through the filters and out to exhaust. To do that it must overcome the resistance to flow created by the filters and the ductwork. Conversely, static pressure or static resistance is a measurement of resistance generated by the ductwork and the filters in baghouse. This also is measured in inches of water gauge.

Why Important? – Without sufficient CFM the sources will not be vented adequately. Poor venting directly causes damage to equipment, high emissions, loss of reclaimed product and hazardous environment (especially of concern in facilities handling combustible dusts or hazardous materials). Low CFM can also negatively affect air velocity, air to cloth ratio, and vacuum pressure, other key design parameters.

Air Velocity and Minimum Conveying Velocity

What are Air Velocity and Minimum Conveying Velocity? – Air velocity within the system is measured in feet per minute, or ft/m. The system must be carefully engineered to keep the air speed within an acceptable range to prevent two major issues. Air speed is related to CFM as follows: ft/m = CFM ÷ cross sectional of duct (i.e. size of duct).

Dust builds up within the ductwork when the air velocity is too low causing blockages and affecting airflow and performance.

Dust builds up within the ductwork when the air velocity is too low causing blockages and affecting airflow and performance.

Why Important? – High air velocity can quickly wear holes the ductwork by means of abrasion (especially abrasive dusts like metals, ceramics, etc.) or can break up delicate conveyed products such as processed foods (cereals), pharmaceuticals, and others. Of greater concern is low air velocity, which can cause dust buildup within the ductwork and lead to poor dust capture at inlets. For a dust to travel suspended in air it must most at or above the minimum conveying velocity for that product. If it drops below that minimum speed at any point in the ductwork the dust will begin to settle or dropout of the airstream, which then accumulate into large piles that eventually choke off the duct. These accumulations of dust within the ductwork create major safety hazards. When combined with an ignition source (such as a spark or ember) they provide ample fuel for a combustible dust fire or explosion, which then can propagate throughout the entire system, being continually fed by dust accumulations further downstream until it reaches the dust collector. Additionally, these accumulations can eventually become so large that the duct collapses under the added weight.

Need Help Designing Your Baghouse?

Looking for help designing your dust collection system? Let our us use our 40+ years of expertise to help you select the right system for your application.


Air to Cloth Ratio

What is Dust Collector Air to Cloth Ratio? – The ratio of gas volume (ACFM) to total cloth area (sq. ft.) of the baghouse. First calculate the total cloth area of your collector by calculating the total filter area of each filter (bag diameter x 3.14 x length ÷ 144 [for number of inches in a square foot] = filter cloth area) and then multiply that figure by the total number of bags in the collector. Take the CFM of the system and divide it by the total filter cloth area to get your air to cloth ratio.

Why Important? – For the baghouse to capture the dust from the airstream the unit must have a sufficient number of filters. As you push more air through the same amount of filter material the collection efficiency goes down. Maintaining an adequate air to cloth ratio enables the baghouse to operate at peak efficiencies, collecting more than 99.9% all dust particles that pass through it. For most applications, anything less than near peak efficiency will result in excessive emissions, violating pollution regulations and creating hazardous environment for workers and neighbors.

Putting All 4 Variables Together and Designing Your System

Now that we have discussed the 4 key design considerations, we will now see how to design a baghouse dust collection system so as to maintain all 4 of these parameters within acceptable ranges to ensure proper operation. Our next section is titled: Design Process for Your Baghouse Dust Collection System

Next Section – Part 3 – Design Process for Your Baghouse Dust Collection System

 Baghouse Design Guide Overview dust collector design and sizing

Dust collection systems play a vital role in many commercial and industrial facilities. Whether part of a system process, used to capture harmful pollutants from furnaces/boilers, to convey dry bulk product or to maintain a clean and safe work environment, dust collection systems need to function at near constant peak efficiency for facilities to operate safely and productively. While maintenance and proper operation play a large role in keeping these systems running properly, many facilities face challenges due to improper system design and engineering.

Many users rely on outside vendors or so-called “experts” with little to no actual dust collection experience to design and engineer a system for them. Other times vendors may purposefully undersize a system in order to undercut other potential suppliers regardless of how it actually performs in the end for their customer. Still others design their own system in-house thinking it an easy process that just any engineer can accomplish with little to no outside guidance. These cases frequently end with an inadequate dust collection system that cannot meet the needs of the process, resulting in high emissions, lowered productivity, hazardous work environments or all three! So what can facilities do to ensure they do not encounter these same issues?

Need Help Designing Your Baghouse?

Looking for help designing your dust collection system? Let our us use our 40+ years of expertise to help you select the right system for your application.

In our experience, an educated user benefits the most and becomes best customer. With that in mind, we have prepared this guide (broken into 4 major sections) to assist users in designing and properly sizing a dust collection system. By following the direction in this guide closely, you can effectively estimate what kind of system you require and then use this information as a basis for gathering quotes and additional assistance.

This guide is NOT an exhaustive course on dust collector design. Each system presents unique circumstances that affect the general operation of a baghouse system. As such, the guidelines present in this guide should be used only to estimate the sizing of your system. A qualified, and experienced dust collection system OEM should be consulted before purchasing any equipment or making design changes.

Now let’s get right into it! First we start with the four key dust collector design variables.

Next Section – Part 2 – The Four Key Baghouse System Design Variables

 Baghouse Design Guide Overview

Key Points to This Guide

  • Many So-called “Baghouse Experts” know little about proper dust collection design and operation OEMs and sales reps frequently undersize systems to win contracts leaving customers with a system that does not work
  • Educated clients can determine the general size they need and use it as a basis to compare quotes from multiple sources
  • Understanding principles of dust collection system design enables facilities to make better decisions regarding baghouse maintenance, operation and safety
  • Designing a baghouse with the correct variables CFM, air velocity, static/vacuum pressure/resistance, number of pickups

    How large of a baghouse do you need? How do you determine how many filters you need? What air to cloth ratio meets your needs? How much vacuum pressure (static pressure) do you need in the system fan? How much CFM do you need?

    These are just some of the questions that may arise when working with dust collection systems are your facility. When designing a new system plant engineers need to decide how large of a system they require before they begin getting quotes from vendors.

    A danger exists when facilities ask outside vendors to design a system for them. Many so-called “dust collection experts” are really just sales rep organizations that have little technical background or engineering experience with these systems. As such, they will often sell whatever product lines they have with little regard for making sure it is the best fit for your specific application. Others vendors purposefully recommend undersized systems in order to undercut other vendors on pricing, regardless of how the end system performs for the customer.

    Plant personnel can easily avoid being sold an undersized dust collection system by conducting research in advance to get a general idea of what size system they need. Then they can use this estimated sizing information as a basis for getting quotes from multiple vendors.
    For this reason, has prepared a detailed series of articles to help educate users on how to properly size their baghouse system. Each article in this series will cover a different step in the process of determining your dust collection needs for your system. This article series will primarily be of use to plant personnel looking to install new baghouses and ductwork systems. However, the information can also be used when troubleshooting existing systems (where capacity may not be sufficient) or when looking to expand capacity on existing systems.

    Click here to download the complete eBook: How To Size a Baghouse Dust Collection System.


    Next Section – Part 1 – Why You Need to Properly Size Your Baghouse System

     Baghouse Design Guide Overview