ebm-papst Fans, Blowers and Technology

By 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.  

Accessorize
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

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.

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.

by Matt Menard, Market Manager - Air Conditioning

In the world of HVAC, motors move conditioned air throughout the system. When a motor fails, cooling or heating ceases, leaving occupants of that building uncomfortable. The motor can be replaced relatively quickly with an experienced technician. However, diagnosing what caused the failure is difficult, time consuming and often ignored.

Motor failure is a major headache that can cost building owners significant money. With limited budgets and resources, implementing a preventative maintenance program on motors to minimize failures can be difficult for most. So what is the solution?

The December 9 issue of ACHR News discusses causes and prevention of motor failure. All of these types of failure can be avoided by choosing external rotor EC motor technology, such as is utilized in ebm-papst’s product line, to boost reliability and efficiency.

1. Belt — Belt tension is critical in avoiding vibrations between the fan wheel and motor. Belts tend to stretch throughout their lifetime, so technicians tend to over tighten during replacement. A belt that is too tight overloads the motor and shortens the lifespan. ebm-papst external rotor motors do not use belts—the fan wheel is mounted directly to the motor rotor.

2. Overheating — This is the most common cause of failure. Dirt buildup on the fan wheel and poorly designed/installed ductwork causes additional strain on the motor resulting in overheating and a shortened lifespan. ebm-papst EC motors have temperature sensors built into the internal electronics package that act as a safety device in the case of overheating.

3. Electrical Fluting — When utilizing a Variable Frequency Drive (VFD) for speed control, users can experience a phenomenon called electrical fluting, which basically equates to a mini-lightning storm that occurs within the motor as voltage and frequency are regulated by the VFD. This ‘storm’ affects the bearings, resulting in premature failure. Electrical fluting is unpredictable and requires additional measures such as shaft grounding kits and ceramic bearings to prevent. ebm-papst EC motors have built-in speed control and do not require a VFD, eliminating the electrical fluting issue.

In addition to eliminating belts, adding temperature sensors and built-in speed control, industry experts such as Jim Connell of AirXChange Inc. believes that ECM fans are more reliable and use less energy than traditional AC motors and drives.  Utilizing external rotor EC motor technology provides not only the most reliable, but most efficient technology available.

By Matt Menard, Market Manager - Air Conditioning

Imagine it’s a sweltering day, and you’ve entered a nice cool office building, school, hospital or large retail store. Aaah. Now imagine you’ve entered that same building but the air conditioning’s not working. Would you accept that the building’s owners shut it off to be green and consume less energy?

Given that 40% of commercial building utility bills go to power their HVAC systems, manufacturers are placing a strong emphasis on energy efficiency in product design for the rooftop units that move the cool (and hot) air that keeps us comfortable at work, in school, and at play.

Ranging from 3 to 175 tons, rooftop HVAC systems provide a turnkey solution, and can be installed on most large buildings. All components of the system, including fans, compressors, coils, electronics and filters are packed tightly into the unit, making installation, operation, and maintenance as simple as possible.

To meet the energy-saving specifications of HVAC system manufacturers, component suppliers have improved the efficiency and operation of the compressors, motors, fans, gas/electric heating devices and controls inside them.

Within rooftop units, compressors and fan motors consume the most energy. However, both have changed dramatically. Compressors have been transformed from inefficient, single speed devices to variable speed devices with electronic controls, making them 40 percent more efficient than their predecessors.

Similarly, fan motors have evolved from inefficient, single-speed units to variable speed, highly efficient designs. For example, the ebm-papst external rotor EC motor touts an efficiency of 90%.

If you’re responsible for keeping HVAC costs down in your building, this is great news. However, motor and compressor technology is nearing the limits of efficient design. Meanwhile, state and federal minimum energy standards are becoming more stringent.

As the mechanical components within HVAC systems begin to hit their efficiency limits, OEM’s are looking to computer-generated designs that can optimize the heat exchangers and aerodynamics in packaged rooftop systems.

Evolving the heat exchanger
Recent work by the NIST (National Institute of Standards and Technology) is focused on air conditioning heat exchangers.  Using computer generated design and analysis, they produced a unique heat exchanger design that yielded an 8% gain in efficiency for the heat exchanger and a 3% gain in overall unit performance. OEM manufacturers are actively pursuing these ultra-efficient designs. They’re also utilizing materials such as aluminum instead of copper in new heat exchangers to reduce cost and improve efficiency.

Evolving the fan
While current fan motor technology is up to 90% efficient, the blades and impellers within a fan are aerodynamically inefficient. Forward curved fans, used in indoor applications, are about 50% efficient. Axial fans, used in outdoor applications, are between 30 and 40% efficient.

Offering expertise in EC motors and aerodynamic design, ebm-papst is working to boost the efficiency of future products through computer generated design and analysis. We’re also working closely with our OEM partners to test new blade and impeller configurations within rooftop HVAC systems, with the goal of reducing power consumption and lowering operating costs to meet their customers’ needs.  So now imagine being green and keeping the air conditioning on! 

by Joe Landrette, Market Manager - Ventilation

Last year’s heavy snowstorms and Hurricane Sandy kept data center operators on their toes as they battled power outages and struggled to keep their cool – literally. These acts of nature got data center operators thinking more about ways to prevent data loss and overheating, long before the next storm hits.

1. Look to the cloud

At the Data Center World expo, from April 28 to May 2, a keynote panel featured two data center stories straight from the eye of Hurricane Sandy. For Alex Delgado, the global operations and data center manager for International Flavors & Fragrances (IFF), cloud email prevented communication headaches, and a back-up facility prevented the company from losing a single order. Donna Manley, IT senior director at the University of Pennsylvania, also relied on the cloud, backing up documentation on Box.net in case servers went down. 

2. Plan for a crisis during the design phase

For Kevin Dickens, deputy director and senior projects engineer with Jacobs Facilities, Inc., Hurricane Sandy also pointed to a need for HVAC back-up. Data center operator zColo experienced issues with its generators during the storm and decided to shut down portions of the cooling system to avoid losing the entire operation. Temperatures inside the center climbed to above 100 degrees Fahrenheit, causing zColo staff to place fans around the center, open windows and shut down some equipment.

“I have wondered what it must have been like for zColo’s mechanical team when they were informed that in order to keep IT online, they would have to shed mechanical load,” says Dickens. “Did they have any idea how the space temperature would react and how fast? Could anyone quantify the near-term and long-term risks to the IT equipment?”

Dickens addresses his own questions by pointing out that the answers should be determined during computer room air conditioner (CRAC) unit design – not during crisis time.   I would expect that the age of the CRAC’s should be reviewed along with their efficiency.  This brings us to the third topic.

3. Consider your CRAC’s age

Another consideration when creating your crisis plan: How old is the CRAC? Over 70% of the 500,000 data centers around the world are greater than 7 years old.  An old and less-efficient CRAC will put a drain on your utility bill as well as eat at your UPS capacity when crisis hits. Replacing fans within the CRACs with direct-drive EC fans means less wear and tear and, therefore, increased reliability and a longer life span.  Other benefits include:

• 10 to 30 percent in energy efficiency gains.

• A return on investment within six to twelve months.

• Lowers the UPS requirements – increasing capacity for power outages.

ebm-papst offers the largest range of fan and blower sizes, along with some of the most efficient motor technology in the world.  We currently supply a range from small tubeaxial fans in blade server applications up to some of the largest fans used for data center building facilities cooling.  This proficient knowledge and product blend in IT, HVAC, and Data Center equipment position us to best address upgrades to existing cooling equipment as well as brand new cutting edge ‘green’ builds with alternative cooling methods.  

Have you recently experienced a data center crisis?  Share your story below. Interested in exploring data center cooling solutions?  Give us a call at 860-674-1515 or email sales@us.ebmpapst.com.