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How to help your HVAC system ‘tone it down’

describe the imageBy Matt Menard, Market Manager - Air Conditioning

Remember the hotel room where you barely slept because the AC constantly cycled on and off?  

The HVAC systems in our homes, offices, hotels and other buildings should keep us comfortable no matter what the weather is outside. And while we expect these systems to perform on demand, we certainly don’t want to hear them running.

What strategies can we help supress the sound and vibration of essential HVAC components?

Internal compressors and fans are the main sources of noise. If the fan’s rattling or the compressor’s banging, clanking, hissing or rattling, getting the system inspected and serviced should be your first priority.

However, cooled air that moves through systems and ducts can create additional sounds. These noises may require a variety of approaches that building HVAC and maintenance pros can address during design, installation or retrofitting.

Size It Right
According to a recent column in HPAC Engineering by Michael Ivanovich of the Air Movement and Control Association International (AMCA), even the most efficient fan will perform poorly if not sized properly.

Mike’s 14-point checklist can help HVAC engineers save energy, reduce noise and maximize efficiency.

Hide It
Any air conditioner that is in a room with people is going to be noisy, which is why most are located elsewhere. Ideally, the only noise that should be heard is that of air flowing into the room.

Placing the air conditioning equipment in a basement, attic or mechanical closet will reduce noise from the mechanical components. In addition, the bulky equipment is hidden from day-to-day life.  

A wide range of products on the market can help reduce HVAC noise. Acoustical wraps or blankets can surround compressors to suppress high-pitched tones. Duct liners absorb noise before it leaves the ductwork. Soft-surfaced insulation can

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be used on the inside of the unit cabinet to muffle noise and to provide thermal insulation.

Products such as our AxiTop diffuser and FlowGrid air inlet grill address noise associated with airflow. By reducing the turbulence on the intake of a fan, the FlowGrid minimizes low-tone frequencies commonly associated with large fans. The AxiTop accessory increases the aerodynamic efficiency and reduces sound levels on ebm-papst axial fans.

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Slow It Down
The simplest way to reduce the sound levels produced by HVAC systems is to slow them down. By reducing the rotating speed of the motors (fans and compressors), you reduce the motor noise as well as the noise caused by airflow. Our EC motors are equipped with integrated speed-control capability, providing lower noise and energy consumption when slowed down.

What are your HVAC acoustical nightmares, and how are you solving them? Log a comment below!

About Matt Menard
With 12 years’ experience in HVAC systems, Matt Menard, Market Manager – Air Conditioning at ebm-papst Inc., actively supports designers’, manufacturers’ and integrators’ with a wide range of air-moving products. Matt holds a BS in mechanical engineering from Rensselaer Polytechnic Institute. He enjoys skiing, golf and spending time with his wife and two children.

Zero Governor (GB-ND) Gas Valve Basics

describe the imageby Dave Hillburn, Business Development Manager - Heating

To better serve our heating customers with one stop shopping, and to complement our existing line of premix gas blowers, ebm-papst acquired the GB series gas valve line from Karl Dungs GmbH on April 1, 2011. Since then we have updated the design, manufacturing, and system integration of these gas valves to better support current and future growth opportunities. So let’s take a look inside these gas valves to better understand their basic functionality and target application.

What’s under the hood? The primary role of a gas valve is to safely shut-off and control the flow of natural or propane gas to a heating appliance. Our product documentation describes this gas valve as a multi-function gas control valve; however, this is not just a safety shut-off valve but a combination dual safety shut-off valve, zero governor regulator, and throttle all in one. So let’s first define the role of each of these components:

Dual Safety Shut-off Valve: Allows the flow of gas to the appliance and more importantly shuts off the gas flow when the control system no longer senses flame. Two points of shut-off are required to be a safety shut-off valve that is in compliance with ANSI Z21.78 and CSA 6.20; therefore, if one valve fails to close the second valve will close and stop the flow of gas.

Zero Governor Regulator: Controls the outlet pressure of the valve with the goal of zero pressure at the outlet allowing the flow of gas to only occur with a negative pressure signal from the venture mixer.

Throttle: An adjustment that defines the maximum gas flow through the gas valve at high fire.

Now let’s take a look at a cross section view of a GB series gas valve to further see how these components are integrated. Gas enters the gas valve at P1, travels through the dual shut off valves (V1 & V2), enters the zero governor regulator (#13), exits the regulator through the throttle, and then exits the valve through the outlet at P2.

GB Series Gas Valve
Figure 1.0 - Cross Section View of GB Series Gas Valve

Perhaps the two most important operational features of the gas valve are its throttle (# 9) and offset (# 15). The position of these adjustment screws are critical to  ensure clean combustion at high and low firing rates. The following graphic illustrates the effects of the throttle and offset on CO2 verses burner load. As shown in Figure 2.0, the throttle adjustment will affect the CO2 at high fire and the offset adjustment will affect the CO2 at low fire. As a general rule of thumb, less excess air (e.g. CO2 = 9%) is required at high fire and more excess air (CO2 = 8.5%) is required at low fire to  ensure proper burner cooling when the flame is closer to the burner surface.

Application Gas Air Unit

Figure 2.0 - Gas Valve Adjustments for Burner Load vs CO2

Application: The gas valve is one component in a gas air ratio control (GARC) system that includes the premix gas blower, venturi mixer, and burner control that work together to safely control and monitor the air-gas mixture and combustion process in these appliances (Reference Figure 3.0). Typical applications for these gas valves include high efficiency condensing gas boilers, water heaters, humidifiers, and commercial cooking equipment.

System Gas Air Assembly
Figure 3.0 - Components of a Gas-Air Ratio Control System

About Dave Hillburn
Dave Hillburn works with ebm-papst customers to incorporate the right system solutions into their residential and commercial heating applications. With seven years hands-on experience in combustion design, he helps optimize these systems’ output and energy efficiency. A graduate of Central Connecticut State University with a BS in Mechanical Engineering Technology, Dave enjoys playing drums and guitar, sports and travel.

Four Questions to Choose The Right Fan

describe the imageBy Scott Beauchemin, Vice President – Engineering

Customers often ask what they believe to be a simple question: what is the most efficient fan?

Their logical goal? To identify the most efficient fan type, then select that type for all uses.

The simple answer? Backward curved impellers have the highest peak static efficiency. But if you’re seeking the best match for your specific heating, cooling or ventilation needs, it’s not that simple.

Here’s what we ask to make sure customers get the right fan for the right application:

describe the imageWhat’s your operating point? The operating point (or duty point) is the target air flow rate in cubic feet per minute and a system resistance (or impedance) in inches of water. The target flow rate is usually a known value. The system resistance or impedance is not always available, but it’s essential in selecting the correct fan.

Here’s the experiment I conducted that illustrates the flaw in a “one fan type fits all” approach. I chose two operating points with the same flow rate but with system resistances that differed by a factor of two. I looked at backward curved impellers and axial fan solutions for both operating points.

The backward curved impeller provided lower power consumption and noise for the higher system resistance level. But the axial fan consumed less power and generated less noise for the lower system resistance. Keep in mind: the flow rate didn’t change.

What’s your flow path? Selecting a fan based solely on the operating point will not necessarily lead to the best results. The path that the air must take through the system must be factored into the selection as well.

The impact that the air flow path has on a fan’s selection can be dramatic – it can make a very efficient fan perform very poorly. Changes of direction or sudden contractions in the flow path that could choke off the flow.

For example, if the air must follow a right angle, a centrifugal fan with a backward curved impeller or a forward curved blower might be a better solution than an axial fan since the centrifugal fan naturally turns the air 90 degrees.

What are your design goals? While the operating point defines the most important variable, power consumption and noise reduction are huge drivers. When noise is a critical factor, the best solution is typically a larger fan running at the lowest possible speed.  

What are your space constraints? Selection of the right fan must consider the available space within the application. The most efficient or quietest fan may not fit within the available space.

Fan selection can’t be viewed as a one-size-fits-all approach. It’s really a compromise between variables. The key to success in finding the right fan is to identify which model results in the fewest compromises.

What fan selection challenges have you struggled with? What solutions have you found? Join the conversation — leave a comment below!

About Scott Beauchemin
Scott Beauchemin began his ebm-papst career 15 years ago as an applications engineer. Now Vice President of Engineering, he puts his two decades’ experience in airflow and acoustic testing to work in exceeding customer expectations with fans and blowers that meet their applications’ efficiency and low-noise requirements. Scott earned his M.S. in Mechanical Engineering at Rensselaer Polytechnic Institute and his B.S. in Mechanical Engineering at Worcester Polytechnic Institute. In his free time, he enjoys golf and running.

ebm-papst shares latest technology at annual American Society of Gas Engineers!

describe the imageby Tom Costello, Market Manager  Appliance & Heating Gas

This past summer, Tom Costello, Market Manager – Appliance & Heating Gas, was invited to speak at the American Society of Gas Engineers (ASGE) National Conference on the subject of gas-air ratio control technologies for high efficiency gas fired appliances. Tom was one of six speakers presenting on a wide variety of topics that included high altitude testing; comparison of fossil fuels and renewables; portable combustion analyzers; intellectual property and recent changes to patent
law; emerging TomCostello Speakingtechnologies in
residential and commercial products and gas-air ratio control technologies for high efficiency gas fired appliances. Like the topics, the speakers were a diversified group representing consultants, component suppliers, non-profit organizations and litigation specialists involved in the gas industry. The conference serves as a great opportunity for the speakers to share with industry colleagues the latest technologies and information that may assist in the demands of their job. Whether they’re an application, design, facilities or project engineer there was at least one relevant topic for each of the more than 60 engineers in attendance.

Tom presented “gas-air ratio control technologies for high efficiency gas fired appliancesdescribe the imagewhich included both electronic and pneumatic systems developed by ebm-papst and in wide use throughout the gas appliance industry. These systems and their components were originally developed for the European market; rising energy costs have spurred the development of high efficiency gas appliances and these systems are now widely accepted in North America. Today, ebm-papst’s product offering includes induced and forced draft combustion blowers, gas valves, air-fuel mixers and gas ignition controls. A component and system supplier to gas appliance OEMs in many of the industrialized countries around the world, ebm-papst continues to develop new technologies that promote the safe use of gas appliances.

To learn more about ebm-papst’s combustion blowers and systems, visit the heating section of our Market Solution Tool or contact


About ASGE
Established in 1954 in Cleveland, Ohio, the Gas Appliance Engineering Society, and later in 1958 renamed to the American Society of Gas Engineers, members met on a regular basis to discuss gas appliance design and safety, and the proper application of new technologies. Today the members continue to promote and educate the necessary information to support gas appliance development into the next century through white papers, technical conferences, and seminars. The American Society of Gas Engineers is also recognized by gas utilities and gas appliance certification agencies who acknowledge the benefits the organization have brought to the industry.

About Tom Costello

If it cooks or chills food, keeps us warm or improves how something’s manufactured, odds are it requires ventilation. During his 27 years in the industry, Tom Costello has supported the evolution of air movement and combustion systems for residential, commercial and industrial food service, heating and process applications. As market manager – appliance heating and gas at ebm-papst for the past 15 years, he’s helped designers, manufacturers and distributors incorporate the latest fan, blower and motor designs into their products. Tom received his B.S. in mechanical engineering technology from Northeastern University. In his free time, he enjoys golfing, scuba diving and home renovation.

What is the Ultimate Global Benchmark for Quality Management?


By Jack Derewonko - Quality Systems Manager

Above and beyond statutory and regulatory standards, ISO 9000 certification is designed to help organizations ensure they meet the needs of customers and other stakeholders related to their products or services. Over a million organizations worldwide are independently certified, making ISO 9001 one of the most widely used quality management tools in the world today.

At ebm-papst, the ISO 9001 quality system is used to design and manufacture quality products of the highest degree. Thebenefits of ISO 9001 are far reaching and impact all areas of our company.  A consistent approach to meeting customer requirements, improving all aspects of product performance and reducing the defect rate ensure operation savings. 

To achieve ISO 9001 certification, a company is required to fully document a quality control program and follow the procedures it writes.  This does not mean the products are certified to ISO 9001 but the quality system is certified.  The ISO 9001 quality system at ebm-papst reduces operational costs and improves customer satisfaction. 

  • Increased marketability – customers recognize ISO 9001 certification as an important factor when selecting suppliers.  

  • Product performance – ebm-papst’s customers expect our products to perform at the highest levels.  We achieve this goal with solid designs and well documented quality control programs.

  • Reducing operational expense – quality programs like corrective action, internal audits, and continual improvement reduce defect rates and improve the efficiency of our production lines.

  • Increase customer satisfaction – high quality products help to meet customer expectations which leads to satisfied customers.

  • Improved internal communication – Some of the ISO 9001 requirements focus on self-assessment.  This helps ebm-papst employees understand the interaction between departments.  We have a focus on internal customers so process controls are established.

  • Improved supplier relations – ebm-papst suppliers play an important role in product quality.  We have systems like supplier audits and performance measurements to improve and manage our supplier base.  

Without proper planning and training, there can be disadvantages of an ISO 9001 quality system.  Excessive documentation can lead to control issues and loss of important data.  Too few records will leave you without evidence of compliance. At ebm-papst, we are striving for a paperless system which will save time, improve quality, and lower our impact on the environment.



About Jack Derewonko
Quality is part of the ebm-papst Inc. DNA; Jack Derewonko oversees the processes that keep it that way. As Quality Systems Manager, Jack applies his 13 years of expertise in managing the company’s ISO9001 and IS014001 systems. He also oversees the company’s quality control department, ensuring that return material authorizations, credits, calibration work and corrective actions are properly handled and documented. Jack received his bachelor’s degree in mechanical engineering and materials science with a minor in English from the University of Connecticut. Outside of work, he enjoys fishing, photography, mountain biking, skiing and golf.

How to tackle the email beast and make face-to-face count

describe the imageBy Don Beckwith, Senior Vice President  Finance and Administration

Today, every organization struggles to find the most effective way to channel internal communications among its employees. Across many departments, how do we best synchronize our conversations as we design, build, deliver and service our products? Deadlines challenge us to balance our digital exchanges with old-fashioned human interaction. defines information fatigue syndrome as “a weariness or overwhelming feeling of being faced with an indigestible or incomprehensible amount of information.” That’s what we face in today’s age of data overload, both at work and at home. So we ask ourselves… are high-tech tools compounding the problem? A study reported in Inc. noted that half of the average employee’s time is spent on email and other “necessary, yet unproductive tasks.”

New York Times columnist Sherry Turkle observed that we’re sacrificing meaningful conversation for expedient connection. Increasingly, we are hiding behind email, IM messages and various social media channels rather than having a real-time conversation.

LifeHack and recently published a useful (and funny) Do I Really Need to Send That Email? decision tree-infographic to help us re-think how we manage our In and Out boxes.

Here are a few helpful tips:

  • Do you sit near the colleague(s) receiving your emails? Walk over and talk to them or set up a brief meeting.

  • Think twice about the people that you’re cc’ing. For every 100 people needlessly cc’d, 8 work hours are lost. (TechCrunch)

  • Avoid forwarding a thread of multiple emails to a new recipient who will need to read the entire anthology in order to understand what you need; a true time-waster!

  • A big no-no: Using email to negotiate a contract or resolve an issue.

  • Is what you’re trying to communicate more than a couple paragraphs? Does it require a series of detailed decisions or responses? Schedule a face-to-face or phone meeting.

  • Is the decision maker or team located in another state or country? This is where technology rules. A number of solutions—including videoconferencing, Skype, GoToMeeting and FaceTime—help us easily collaborate without the need to travel to other locations to be productive.

  • Is the news extremely important? Confidential? Bad? Shut off the computer and get in front of the person who needs to hear it.

Admittedly, today’s digital communication tools play an important role in our daily business interactions. However, we need to make an extra effort to engage in face-to-face conversations and fight the urge to shoot off an email or text!

Manufacturing’s biggest challenge

describe the imageBy Bob Sobolewski - President and CEO at ebm-papst Inc.

“There are only three ways that a country builds wealth – you make things, you mine things and you grow things. Everything else is ancillary to that.”
– Pat Lee, Fabricators & Manufacturers Association

U.S. manufacturers contributed $2.08 trillion to the economy in 2013. For each dollar spent in manufacturing, another $1.32 is added to our economy, the highest multiplier effect of any economic sector. (National Association of Manufacturers).

Here in Connecticut, 4,826 companies employ 167,900 manufacturing workers who earned $12.4 billion in wages and salaries last year. Every $1 million in manufacturing output in our state translates to $2 million in sales in other industries, 8.3 new jobs and $700,000 in new personal income (CBIA).

With a resurgence of manufacturing in the U.S. — including companies that are insourcing jobs and facilities — you’d think we’d be riding high with no complaints.

Not yet.

National Metal Fabricators President Tom Bonine lists seven of manufacturing’s biggest challenges. To strengthen companies that make quality products and pay good wages, the National Association of Manufacturers urges our elected leaders to choose policies that make this country a better place to invest, a better place to innovate and a better place from which to export.

Having managed growth at ebm-papst Inc. for nearly three decades, I share the views of my fellow Connecticut manufacturers. Federal and state regulation, taxes, reduced demand, raw material prices, overhead costs and competition keep us up at night.

My view? There’s no production without education. As highly experienced employees begin to retire, I worry about preparing new generations for careers within our advanced manufacturing facilities. 

There are solutions we should support, including innovation and training hubs nationally and locally. The National Network of Manufacturing Institutes has four of their 45 projected hubs up and running in in Youngstown Ohio (additive manufacturing), Chicago (digital manufacturing and design), Detroit (lightweight metals, and Raleigh, North Carolina (power electronics).

Here in Connecticut, three manufacturing centers offer a certificate in advanced manufacturing machine technology, while Connecticut’s colleges and universities offer some of the most competitive engineering programs in the country. 

Our most important challenge? Convincing more than half of U.S. teenagers that their perceptions of manufacturing are false. What this means is that promoting manufacturing careers to high school kids isn’t enough. We have to start much earlier.

Is your company struggling to find qualified and enthusiastic people to help you innovate? Partner with your region’s engineering programs, technical training programs and centers. But also go deeper by supporting programs that help our young children embrace the excitement, fun and challenge of inventing and building things.

About Bob Sobolewski
Robert (Bob) Sobolewski
is President and CEO of ebm-papst Inc. A member of many community and industry trade organizations and associations, Bob has been recognized for his support of educational programs, especially those that bring schools and the workplace closer together. He serves as President and Chairman of ingenuityNE and NE FIRST, Chair of the Connecticut Executive Advisory Board of FIRST, a member of the Fairfield University School of Engineering Executive Advisory Board, Vice Chair of the Connecticut Business and Industry Association Board, a Director of Okay Industries, Inc., and a member of the Board of Directors of the Electronic Component Industry Association (ECIA) Foundation.

Will you be chillin' (or sweatin') on public transportation this summer?


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By Joe Giacona, Market Manager - Transportation

It is interesting how advances in technology have forced their way into just about every aspect of our world and drive improvements in efficiency that benefit us all.

Mass transit in North America provides a great example of this. The term “mass transit” (i.e. public transportation) is typically characterized by modes of travel such as buses, subways and trains – generally in greater metropolitan areas.

Most people don’t realize how many advances have taken place in mass transit over the past 5-10 years, and how these vital improvements have directly benefitted the environment by proportionately reducing energy consumption.

Gone are the colossal smoke billows of yesteryear – replaced by clean diesel burning engines, alternative fuels (such as CNG), hybrid electric powered vehicles, state-of-the-art HVAC systems and controls.

As technology advances, ridership has increased significantly. Since 2004, the population has grown 7% and  passenger transit miles have increased by 15%, all while highway travel has not significantly increased. This comparison exemplifies the important role mass transit plays in reducing the nation’s energy use and greenhouse gas emissions.

The combination of reduction in private passenger vehicle travel, reduced automobile congestion, and  decrease in accrued vehicle mileage is directly related  to the accessibility  of mass transit which conserves over 4 billion gallons of gasoline and 37 million metric tons of carbon dioxide emissions. According to the U.S. Environmental Protection Agency’s Greenhouse Gas Calculator, it would require 7.2 million acres of new pine or fir forests per year to match the annual carbon dioxide reductions provided by public transportation. Priced at $3.60 per gallon, the annual conservation of 4 billion gallons of gasoline saves the U.S. consumer $14.4 billion per year (Source: APTA 2013 Fact Book).

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Technological advances have been the impetus for state-of-the-art HVAC systems and controls in transit and rail vehicles. ebm-papst fans play a leading role in providing comfort to millions of people on thousands of transit vehicles every day. ebm-papst brushless EC fans are considered the “gold standard” by many HVAC and bus manufacturers worldwide. By delivering better air flow and higher efficiencies than brushed alternatives, ebm-papst has earned this brand recognition. Our fans provide energy and fuel savings in all modes of operation. ebm-papst EC motor technology also allows manufacturers to take further steps to reduce power consumption by offering variable speed capability; this automatically ties fan speed to actual cooling/heating demand.. The unparalleled reliability and performance of ebm-papst fan technology, combined with operational efficiency, provide end-users unmatched value and comfort.

To learn more, visit the transportation section of our Market Solutions Tool or contact Joe Giacona at ebm-papst Inc.


About Joe Giacona

Joe Giacona knows that HVACR components within transportation systems must deliver performance and reliability over the long haul. As market manager – transportation at ebm-papst, Joe’s 30+ years of diverse experience in HVACR help him recommend the best ebm-papst products to heat and cool customers’ buses, trains, trucks and other vehicles across North America. Joe actively supports the company’s market development, forecasting, field sales coordination and customer relations. He holds a B.S. in physics from Brockport State College and a B.S. in industrial engineering from the University of Buffalo. In his free time, Joe enjoys cooking for his family, do-it-yourself projects, keeping his 1960 Corvette Roadster in peak form, and making wine from New York and California grapes.

Cooling the equipment that keeps us well

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by Todd Cardillo, Market Mager -Industrial

ebm-papst Inc. has provided air-moving solutions  for medical equipment and  devices for decades. Beyond the UL, CSA, CE, EMC and other quality standards that our industrial customers must meet, medical equipment and device manufacturers must comply with FDA (US Food and Drug Administration) requirements. 

When new products are brought to market or existing ones are modified, FDA approvals play a critical role in our customers’ qualification processes.  The FDA tests and regulates medical devices and equipment – ensuring they are safe and effective for human use. This type of testing can be expensive and lengthy. Medical equipment components need to be tested for robustness and extended life expectancy. 

Since most medical devices incorporate electronics that generate high levels of heat, these frequently require internal fans or blowers. This is where we’ve applied our expertise. 

As one example, several of our axial fans are used within a computed tomography (CT) scan machine. Some of the fans are located in the gantry portion of the scanner, which rotates at a high velocity. For this application, our fans need to reliably operate at up to 75 G forces to cool the gantry during motion.  To address the air flow needed for controlling equipment ambient temperatures, as well as acoustic noise and environmental requirements, it’s crucial that the optimum air moving device is chosen at the beginning stages of any medical equipment project. 

For more details on the ebm-papst products available to cool medical equipment and devices, visit the medical equipment applications area in our Market Solutions Tool.

About Todd Cardillo
At ebm-papst Inc. for more than 18 years, Todd enthusiastically embraces his current role as Market Manager for the Industrial market. He continuously builds new relationships and strives to deepen interactions with existing customers. Todd’s commitment to the company drives him to thoroughly educate customers on ebm-papst’s product offerings, while at the same time learning all he can about each customer’s business applications. He has a Bachelor’s degree in Mechanical Engineering. When not at work, Todd treasures his time with his 3 adventurous children – engaging in triathlons, mountain biking, adventure races, skiing and traveling.


Fan Noise: How to Control Air Turbulences



Turbulence 320px

Turbulence. It happens. Luckily, ebm-papst has a solution for noisy systems.

If you’ve tossed and turned at night, unable to sleep because of humming sounds from your home’s air conditioner, you know these noises are intolerable. That same distraction from a heating or A/C system can strike anywhere… in the office, at the store, at a restaurant.

But did you know that it’s usually the turbulence in an air-moving system – not the components – that makes your ears ring?

Fans are an essential part of today’s refrigeration, air conditioning and ventilation systems.  They are designed and tested to minimize noise in thousands of applications. However, there are wide differences in how fans are installed and configured, the conditions in which they operate, and their location within the air system. These variables can create air inflow and outflow disruptions that raise the ‘loudness level.’

For example, the housing walls of rectangular heat exchangers can generate a backflow that creates pressure fluctuations on the fan blade. These turbulence ‘vortexes’ drastically increase a fan’s low-frequency (tonal) noise. While it’s not possible to compensate by changing the fan itself, it is possible to straighten the flow of air moving into the fan and balance the pressure of air moving out of the fan.


Over the past few years, ebm-papst has developed two passive add-on devices — the FlowGrid air inlet grill and the AxiTop diffuser. In distinctive ways, each improve how air moves into and out of our axial and centrifugal fans.

The FlowGrid air inlet grill has a straightening effect on the inflowing air, reducing acoustical levels and considerably reducing tonal noise.

In a condenser application, fitted with an axial fan, the FlowGrid air inlet grill reduces overall sound levels by 3.9 dB(A) and tonal noise by 16 dB. In a low profile (250 mm diameter) air conditioning device, the FlowGrid reduces sound levels by 2.5 dB(A) and reduces tonal noise by 9 dB.

Condenser Sound Measurement Chart

This graph shows actual results of sound measurement performed on a condenser. The air inlet grill achieves a significant reduction in sound pressure levels and considerably weakens tonal noise.




While FlowGrid works to reduce low-frequency noise on a fan’s inlet side, the AxiTop diffuser reduces mid-frequency noise on the fan’s discharge side. How does this work? AxiTop operates like a reverse nozzle, increasing pressure and significantly reducing discharge losses. Efficiency increases and operating noise decreases.

Using both AxiTop and FlowGrid on a condenser fitted with a 31.5 inch (800 mm) axial fan, with outside air drawn through a heat exchanger, we’re able to reduce the fan’s noise level by 5.8 dB(A) and tonal noise by 20 dB.

Third Octave Band Sound Power
Setting new standards for their quiet, energy-efficient operation, both devices are advancing technology and creating ideal operating conditions for fans. As a result, we can all sleep better!

Contact our application engineer for additional information at 860 674-1515 or by e-mail at

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