How to Select the Right Cooling Fan

In many devices and systems, the buildup of heat can lead to reduced performance, prematurely deteriorated components and materials, and increased safety risks. For these reasons, many pieces of equipment utilize cooling fans to dissipate heat buildup and avoid these potentially costly consequences.

Since cooling fans are used in a wide range of products, they are available in a variety of designs and configurations to suit different application requirements and restrictions. While this broad selection makes it possible for product designers and engineers to find a component that meets their exact needs, it can also make it more challenging to find the right one. The following article serves as a helpful selection guide for readers, outlining the steps to follow when choosing a cooling fan for a particular application. 

The Cooling Fan Selection Process

Step 1: Perform a Thermal Analysis

The first step in the cooling fan selection process is performing a thermal analysis. A thermal analysis determines the amount of heat generated inside a particular piece of equipment or during a particular process. The result can be used to calculate the volume of air needed to cool the device or system. 

Thermal analysis operations use sensors and other instruments to determine the source(s) of heat and the amount of heat generated by each source. The heaviest consumers of power and, consequently, the biggest contributors to heat dissipation are often components like microcontrollers, processors, FPGAs, and MOSFETs. Once the necessary information is obtained, the amount of airflow required to cool the device or system can be calculated. Afterward, the cooling air path can be mapped using sensors and software to ensure that all major heat sources receive the air needed to cool them sufficiently. 

Step 2: Determine the System Impedance

After the thermal analysis is performed and the required air volume is calculated, the next step in the cooling fan selection process is determining the system impedance. System impedance refers to the sum of the pressure drop experienced as air travels between the fan’s inlet vents and exhaust vents. If a system has multiple air paths, the individual impedance values are added. The value(s) can be measured for different rates of airflow with pressure sensors or by placing the system in an air chamber. 

Step 3: Choose the Type of Fan

After the system impedance is identified, it can be used with the calculated airflow requirement to gauge the static pressure needed for the system. This information can then be utilized to determine which fan will serve as the best solution. 

Cooling fans are divided into two categories based on the way air flows through them. 

• Axial fans have air enter and exit in the same plane. Similar to an airplane propeller, they have blades that generate aerodynamic lift and pressurize the air. They can provide high airflow and are ideal for applications involving relatively low static pressure. 
• Centrifugal fans have air enter in one plane and exit in another. They have rotating impellers with blades that increase the speed of air streams and convert them into pressure. They can produce high pressures and are suitable for applications involving harsh conditions (e.g., moist or dirty air streams). 

Some of the factors to consider when selecting between these two fan designs are: 

• Pressure
• Airflow rate
• Efficiency rate
• Space constraints
• Noise generation
• Drive configuration
• Operating temperature range
• Operating environment range
• Cost
• Delivery time
• Availability

Step 4: Final Considerations 

In addition to the above, other considerations to keep in mind when choosing a cooling fan for a system include: 

• Integrating speed controls: Fans that run continuously at fast speeds will wear out quickly. Integrating speed control elements that alter the speed of the fan when needed can significantly increase the overall service life of a unit. 
• Incorporating performance monitoring circuits: Performance monitoring circuits track fan performance to identify potential malfunctions before they occur. 
• Establishing maintenance schedules/programs: Regardless of the fan you choose, it is essential to create and implement a maintenance schedule for it. Otherwise, the unit may break down unexpectedly. A basic maintenance program should cover the following: bearings, belts and sheaves, leakage, motor condition, and system cleaning. 

Quality Cooling Fans From Pelonis Technologies, Inc. (PTI)

Need additional assistance selecting a cooling fan for your application? Ask the experts at PTI! At Pelonis Technologies, Inc., we have developed and manufactured specialty cooling products for commercial and industrial operations for over 25 years. We have the knowledge and skills to answer any questions you may have and find the product that suits your exact needs. Contact us today to get started on your solution.

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Traditional heaters can experience a number of issues that cause discomfort or injury to users, including, but not limited to, hot spots. Positive temperature coefficient (PTC) heaters serve as a solution to these and other problems. 

PTC Heating vs. Traditional Heating

Traditional heaters and PTC heaters have widely different designs and constructions, which results in significant differences in their operation and performance. 

Traditional heaters generate heat using coils and wires. Additionally, they typically utilize a single-point sensor to determine the temperature for the entire heater. This design poses a functionality issue and creates a safety risk since it can lead to the development of overly hot areas on the surface of the heater. 

PTC heaters have heating elements made from barium titanate-based ceramic stones. The material’s unique properties enable a PTC heater unit to self-regulate; it can run open-loop without needing external diagnostic or feedback controls. As a result, PTC heaters are highly reliable, offering consistent and uniform heat without the risk of overheating.

Advantages of PTC Heaters

As indicated above, PTC heaters offer better reliability than traditional heaters, which makes them the more suitable heating option for numerous applications. Other key advantages include: 

• Safer heating functionality. PTC heaters eliminate the safety problems generally associated with heaters that use resistive wire, carbon fiber, or etched foil to generate heat.

• Higher operational efficiency. Since PTC heaters are self-regulating, they can optimize power consumption to achieve and maintain the desired temperature. For example, they will draw at full power at colder temperatures to ensure they reach the threshold temperature quickly.

• Smaller size, lighter weight. PTC heaters can be made to thicknesses as small as .0005 inches, which allows them to have smaller and lighter forms.

• Greater strength and durability. These heaters can withstand significant mechanical abuse, including creasing, folding, and piercing, without experiencing damage or degradation that affects their operation or performance. 

• Bigger cost savings. Since PTC heaters are durable and efficient, they often cost less to run and maintain than traditional heaters in the long, which can result in significant savings for users. 

Innovative PTC Heating Solutions From Pelonis Technologies, Inc. (PTI)

Want to learn more about positive temperature coefficient heaters and why you should use them over traditional heaters? Ask the experts at Pelonis Technologies! We’ve developed and manufactured specialty heating products for commercial and industrial use for over 25 years. This extensive experience provides us with the knowledge we need to answer and address any questions or concerns you may have about these heating products. 

Additionally, combined with our many standard products, vast customization services, and ISO 9000 and ISO 14000 certified manufacturing facilities, it provides us with everything we need to make quality heating solutions that offer superior reliability, efficiency, and safety. Whether you need a stock or highly customized PTC heating unit, our team can deliver. 

Immersion heaters, also known as bayonet heaters, are electrically powered direct contact heating devices used to heat material inside a container. They are versatile, able to be used in a variety of applications and processes where the temperature of oils, solutions, heat transfer fluids, and other liquids must be regulated. Electric immersion heaters often replace other types of furnaces like fuel-based fluid heaters, reactors, infrared, microwave, and resistance heaters. Industrial immersion heaters play an important role in many sectors, from food and agriculture to chemical applications and more.

Applications of Immersion Heaters

Immersion heaters have many uses for both residential and industrial applications. They offer a more accurate, controllable heating method as well as enhanced heating efficiency, broad versatility, and low maintenance requirements. Household uses include electric water heaters, air conditioning, instant hot water taps, steam generators, reactors, and other corrosive or high-temperature applications. Industrial uses for immersion heaters are vast and varied, including:

• Cement curing. Immersion heaters speed up the cement curing process with fast, consistent results.
• Chemical industry. Electric immersion heaters are critical for keeping a stable temperature and preventing freezing of detergents, water, oils, and acidic or basic solutions.
• Food processing. Ceramic immersion heaters are ideal for controlling moisture that leads to the growth of pathogens and bacteria that threaten the quality of food items. Immersion heaters can sterilize containers and heat liquids to meet government regulations and comply with quality standards required of food processing operations.
• Laboratories. Immersion heaters are used in labs for sterilization, autoclaves, and pill drying.
• Nuclear power. Nuclear power plants require pressurized water in reactors to produce steam. Immersion heaters accurately raise water temperatures to keep consistent pressure.
• Oil and gas industry. Immersion heaters allow oil and petrochemical products to flow at cold temperatures by heating them without changing their underlying infrastructure.
• Wastewater management. When temperatures get cold, immersion heaters ensure that water in reservoirs and pipes doesn't freeze to ensure water treatment doesn’t fail.

Immersion Heaters From Pelonis for a Wide Variety of Applications

Pelonis Technologies' ultra-high temperature ceramic immersion heaters provide more efficiency, durability, and flexibility compared to other heaters on the market. Improved efficiency translates to significant cost savings for your project. Our ceramic immersion heaters have a 98% higher thermal efficiency, meaning they can achieve higher temperatures with less voltage.

Key features of our immersion heaters include:

• Corrosion-resistant
• Durable and long-lasting
• Greater heating efficiency for both gases and liquids
• High thermal conductivity
• Needs minimal repairs
• Usable in air or water

Pelonis Technologies offers the highest quality products at competitive costs. Dependable, durable, long-lasting equipment like our immersion heaters saves time and money. Partnering with Pelonis provides an excellent return on investment.

Partnering with Pelonis Technologies

Pelonis Technologies' management team and engineers have over 25 years of experience in product development and manufacturing. We use innovative and flexible manufacturing techniques that allow us to scale production for everything from large-scale to small projects. Our facilities meet or exceed the industry standards such as ASA, ANSI, and MIL-STD, and our L-10 life testing procedures monitor product life.

Our team of experts is here to provide our customers with the services, solutions, or designs to meet their needs. We have the expertise to fully customize our blowers, fans, motors, and heaters to meet specific project needs under the most demanding industrial conditions. Our immersion heaters provide numerous benefits, including superior longevity with minimal maintenance. Contact Pelonis today for questions about our products, services, or processes.

An electronically commutated (EC) fan design delivers the combined benefits of AC and DC Fans. The EC fan's power comes from a brushless DC motor, but it offers the control that AC induction fans have over the fan rotor through a printed circuit board. The electronically commutated fan's DC motor has the advantage of a variable speed control built-in.

An AC electrical supply powers the EC fan, but the on-board electronics convert the power to DC before reaching the motor. The secondary magnetic field generated by the permanent magnets makes EC fan motors considerably more efficient than AC induction motors.

This blog post will discuss the four primary benefits offered by electronically commutated fans.

Increased Efficiency

The high energy efficiency of the EC fan motor comes from the reduction in energy consumption. Even at partial speeds, EC fan motors continue to maintain high levels of efficiency. The secondary magnetic field in EC fan motors comes from permanent magnets inside the rotor. This allows EC motors to conserve energy that would generate a secondary magnetic field like the copper windings accomplish in AC induction motors.

While the EC motor is running, it constantly monitors the electricity powering the fan and makes continuous adjustments to keep fan power optimized. The fan maintains efficiency within a range of speeds rather than a single specified speed. The level of control is similar to the frequency controller used in AC motors, but EC motors can remain efficient at any speed within its design capabilities. These factors help EC fan motors achieve as much as 30% more energy efficiency than AC fan motors.

More Control

EC fan motors use multiple methods of control to deliver better efficiency and simplify control of small or large-scale applications. EC fan motors have a printed circuit board that allows precision control through a computer application. Administrators have control of fan speed, torque, and ramp-up time through a central location, and MODBUS-network protocol for scalable automation of fan controls and simplified 0-10V controllers are also available. The advanced control granted to operators allows for optimum efficiency in a variety of applications, making the fan up to 90% more efficient.

Longer Lifespan

Industries and applications that require reliability and longevity can rely on EC fans for a longer lifespan than AC fans with similar capabilities. AC fan motors have carbon brushes that eventually wear out, but the lack of carbon brushes on the EC fan motor eliminates the risk of wear.

Low operating temperatures are another factor of EC motor longevity. Electronically commutated fan motors maintain a lower temperature compared to similar AC fans, decreasing heat-related failure. More reliable operation and a longer service life can offset the higher upfront cost of switching to EC fans by reducing the need for long-term maintenance, repair, and replacement costs.

Compact & Versatile

EC fans have a space-saving design, allowing them to operate at a high capacity at a smaller physical size. The smaller size is largely due to the external rotor. The weight of an EC motor is four times less than an AC motor with similar capabilities, and the less bulky design delivers better airflow. EC motors are a practical solution in environments where space is of concern.

Why Pelonis?

At Pelonis Technologies, we’re an industry leading vendor thanks to our innovative products, flexible manufacturing capabilities, and portfolio of value-added services. We strive to deliver affordable products made only from the highest-quality materials and are equipped to respond to orders and production runs of any size. Our manufacturing facilities are certified to meet ISO 9000 and 14000 standards, and we strictly adhere to international UL, cUL, TUV, and CE requirements.

If you need high-quality EC fans, Pelonis Technologies can help. Please contact us to see if our electronically commutated fans are right for your design.

Intelligent Motion Control (IMC) solutions modify the start-up and continuous power in brushless DC fans and blowers. These systems control every element of the equipment's functionality with multi-featured, full-wave, in-board circuit designs to ensure each piece of equipment is protected from abnormal or harmful voltage conditions. Not only can the IMC solution control how much power is run through the fan and blower systems on start-up, but they can also provide early warnings about fan malfunctions and energy usage.

IMC solutions are commonly utilized in green facilities that want to maintain a high degree of energy-efficiency, as well as plants with significant amounts of electronic or heated equipment that needs regular cooling. The benefits of Intelligent Motion Controls include:

• Better operating efficiency and performance
• Improved system oversight and maintenance
• Electronic and fan or blower components that last longer
• Fewer voltage fluctuations
• Programmable features to build a customized solution for every facility or application
• Multi-alarm connections that run multiple fans and detect potential malfunctions quickly

Each of these individual benefits work together to make fan and blower systems perform better, longer, and more safely. It's essential to select an appropriate IMC solution that will optimize each of these benefits for the highest return on investment.

Solutions

Pelonis Technologies provides many IMC control solutions for brushless DC fans and blowers. Four of the most popular control types include:

• Pulse Width Modulation (PPWM)
• Over-Voltage (OV)
• Automatic Temperature Control (TPWM)
• Manual Variable Resistor Control (RPWM) 

Pulse Width Modulation

PPWM controls allow facilities to directly manipulate signals within fan and blower systems to control how much time they spend operating on high settings. Complex circuitry systems frequently use PPWM systems to vary how much time equipment operates with a high signal. The system is analog and switches the equipment between high or low settings across a consistent period of time.

The control system works by applying a modulated signal with different frequencies ranging from 30 Hz up to 30 kHz. The high setting's pulse height can range from 3V–10V, and the low setting's maximum pulse height is 0.4V. These differences in voltage and signal change the fan system's duty cycle speed proportionally to the same percentage change in the maximum speed. 

PPWM controls also include:

• Constant Speed (CS) controls
• Inrush Current Protection (IR) controls
• Current Limit (CL) controls

PPWM controls ensure that the fan maintains a minimum speed when the duty cycle is less than 25%, and cap the maximum speed at 4,000 RPM. This setting is called Mode "A" operation.  These systems use an external blue wire.

Over-Voltage

Inconsistent voltage levels can damage equipment, especially if the voltage surges above a maximum allowable level. Over-voltage systems are protective circuits that detect voltage levels and only allow the equipment to operate when the voltage is below an established safety threshold. This maximum operating voltage is typically set at 20% more than the specific rated voltage, but the level can be customized for different equipment. 

Over-voltage systems either shut down power or clamp the output once it gets too high. The control's voltage range is double the rated voltage of the equipment it's protecting. 

OV controls are built-in tools that don't have an external wire.

Automatic Temperature Control

Instead of keeping a facility's fans and blowers on a timer, TPWM systems read the temperature to determine whether the cooling equipment needs to be running at a low or high speed. Operators can customize the upper and lower temperature limits to dictate when the system's settings should change to lower the temperature or hold the temperature steady. 

These systems use a 104J NTC thermistor, which offers 100K at 25° C. Also, the following controls come included in the system:

• Constant Speed (CS) controls
• Inrush Current Protection (IR) controls
• Current Limit (CL) controls

This system has a built-in safety in the event of open or shorted thermistors. In these conditions, the control will tell the fan or fans to run at maximum speeds. Also, the fan's Mode "A" operation will rotate at a minimum of 1,000 RPM in temperature conditions of 16° C (60.8° F) to maintain adequate airflow. These systems use an external green wire.

Manual Variable Resistor Control (RPWM)

Many applications—including controls for generators, DC motor drives, and electric welding controls—need to have manual control. Manual Variable Resistor Control systems allow operators to adjust the fan or blower speed at varying levels with an external variable resistor. The system's speed will change proportionally to the percentage change of the resistor and in correspondence to the percentage change of the maximum speed. 

The systems come with a resistor with a maximum value allowance ranging from 10–100K. The maximum fan speed is 4,000 RPM. The following controls come included in the system:

• Constant Speed (CS) controls
• Inrush Current Protection (IR) controls
• Current Limit (CL) controls

If the variable resistor drops below 25K, then the RPWM automatically enters Mode "B" operation, and the fan will stop. These systems use external orange and white wires.

IMC Solutions from Pelonis Technologies

Choosing the right IMC solution to protect your facility's fan and blower systems is essential. Pelonis Technologies can help you select the best fit. Not only do we have a wide range of Intelligent Motion Controls, our products include rotation detectors, life detection systems, DC voltage system controls, and current source signal control systems. 

Contact us today to learn more about upgrading your system.

Adding intelligent motion controls (IMC) to your fan or blower design can maximize your system’s performance. There are several types of IMC solutions available to add functionality to your fans and blowers. Four of the solutions include a rotation detector, life detection, DC voltage signal control, and current source signal control. In this post, we will discuss each of these solutions.

Solutions

Rotation Detector (Complement)

The rotation detector (complement) (RDb) control is an open collector with hardware similar to the frequency generator (tachometer) (FG) control #2a. The output signal is HIGH when the fan is rotating, but when the fan is stopped or powered OFF the output signal is set to LOW. The output can be connected in parallel to the RDb of a series of fans that end at a single alarm device, which provide a warning if any single fan has stopped working. The RDb control is an external violet wire.

Life Detection

Similar to the RDb, the life detection (LD) control is also an open collector with the same hardware as the FG control #2a. The output signal is HIGH under the fan’s normal rotation, and it is set to LOW when the fan’s rotation speed is below 70% of the device’s rated target speed. Slow rotation may be a sign of aging or wear of the fan or blower, or it could mean there is reduced power supply voltage. The LD control is a brown external wire.

DC Voltage Signal Control

The DC voltage signal (VPWM) control adjusts speed by applying an external DC voltage signal. The voltage input “Vin” can have a value ranging from 1V to 20V, with standard values of 1V to 5V. The fan speed varies linearly, is proportional to the percentage change of the “Vin” value, and corresponds to the same percentage change of the maximum speed. The constant speed (CS), inrush current protection (IR), and current limit (CL) controls are included.

The part number is followed by an additional identification entry, such as V 1 5 20 100 C 500. That number indicates that the fan speed is 1000 RPM (20%) at 1V and 5000 RPM (100%) at 5V. Additionally, the fan maintains the minimum speed if Vin is less than 1V and it stops if Vin is less than 0.5V (Mode “C” operation). The maximum fan speed is 5000 RPM, with a stop point typically set at 20% of the maximum. The VPWM control is an external white wire.

Current Source Signal Control

The current source signal (IPWM) control adjusts speed through the application of an external current source signal. The current input “Iin” may have values ranging from 4mA to 50mA, with standard values of 4mA to 20mA. The fan speed varies linearly, is proportional to the percentage change of the Iin value, and corresponds to the same percentage change of the maximum speed. The constant speed (CS), inrush current protection (IR), and current limit (CL) controls are included.

The part number is again followed by an additional identification entry, such as I 4 20 20 100 A 500. That number indicates the fan speed will be 1000 RPM (20%) at 4mA and 5000 RPM (100%) at 20mA. The fan maintains the minimum speed if Iin is less than 4mA (Mode “A” operation). The maximum fan speed is 5000 RPM, and the IPWM control is an external white wire.

Discover the IMC Solution That’s Best for You

Pelonis Technologies will help you find the perfect IMC solution to your fan or blower designs. We offer rotation detector, life detection, DC voltage signal control, and current source signal control. Learn more about our products and services on our website, where you can also contact us or request a quote.

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The direct current fans, or DC fans, are powered with a potential of fixed value such as the voltage of a battery. Typical voltage values for DC fans are, 5V, 12V, 24V and 48V.

In contrast, the alternating current fans, or AC fans, are powered with a changing voltage of positive and of equal negative value. In general, this changing voltage has sinusoidal shape. Worldwide, the usual value of this sinusoidal voltage may vary in size and in frequency, such as 100VAC, 120VAC, 200VAC, 220VAC, 230VAC or 240VAC, and with frequency (cycles per second) of 50Hz or 60Hz.  

In the past, big AC fans were typically less expensive compared to big DC fans. Today however, their price difference is negligible due to their payback advantage. We will try to point out differences between the above fan types, to help you choose and purchase the correct fan type for your application.

The Pros and Cons of DC fans

DC technology has become much more sophisticated in recent years, and it can now be applied to both residential and industrial ceiling fans. DC fans have motors that rely on permanent magnets in order to attract and repel a rotor around the axis using electronic switching. DC technology is much newer than AC technology, which means there are fewer options available.

PRO: Consumes less power

DC fans are widely regarded as the most efficient type of fans. They consume significantly less power than AC fans. In fact, DC fans consume up to 70 percent less energy to produce the same output as traditional AC fan types.

This means, that a 25-watt DC-driven yields the same results as 100-watt AC fan. This is ideal for commercial settings, like restaurants, allowing you to keep fans running all day without incurring astronomical electric bills.

PRO: Minimal electromagnetic interference

Due to low power used as well as the application of sophisticated electronic switching, the electromagnetic interference of DC fans is minimal. Sensitive electronic devices often use DC fans to prevent electromagnetic interference.

For example, computer applications and equipment rely on DC fans, to prevent overheating while still minimizing electromagnetic interference that could negatively affect sensitive applications.

PRO: Acoustically Quieter

DC fans make use of a new type (sin180) of electronically commutated motor (ECM). Not only are these motors ultra-efficient, they are also incredibly quiet. Because they are so quiet, DC fans are an excellent option for applications such as medical instruments, telecom switches, or car entertainment systems, where noise could be a nuisance.

PRO: Lower voltage

DC fans generally use less voltage than AC fans. The majority of DC fans are low-voltage fans. For example, you can typically find 5V, 12V, and 24V versions of DC fans. Larger models of DC fans, such as 119mm to 172mm fan models, are typically available in 48V. In comparison, most AC cooling fan models are available in 115V, a much higher voltage. Lower voltage also makes DC fans potentially less dangerous.

PRO: Water-Resistant

The DC fans can be used in applications of severe environmental conditions. It is imperative to employ a reliable, high-quality water-resistant model to ensure the safety of your equipment and staff.

Read More: Water-Resistant DC Fans for Harsh Environments

Pelonis Technologies, Inc. (PTI) has been designing, developing, and manufacturing industry-leading AC axial fans and brushless DC fans for more than 25 years. This includes a wide range of severe weather and water-resistant fans, which offer unparalleled dust and water protection while meeting military and NASA material specifications, USP certifications, and UL certifications.

Our harsh weather fans feature an eco-friendly proprietary conformal coating with excellent properties and corrosion resistance, allowing the fans to easily withstand dust, moisture, water exposure, and even full water immersion. Our DC fans also undergo a rigorous vacuum sealing process, enabling them to operate during submersion.

PRO: Intelligent Motion Control

The use of Intelligent Motion Controls in select model DC brushless fans and blowers has already arrived. With Intelligent Motion Controls, the movement of air is now smarter. 

The inclusion of full-wave-in-board circuit design and multiple features leaves no doubt that intelligence has enhanced air movement.

PRO: Variable flow

With minimal additional cost, the DC fan can offer a variety of speed control functions, so that the fan can meet the airflow target of a given application. The fan can be controlled by:

• Voltage
• Current
• Temperature
• Resistance
• PWM signals

CON: May require an AC to DC converter

The AC fans are powered by an alternating voltage source. The DC fans are powered by a constant voltage source. This means that, the DC fan must have an AC to DC converter, either externally or included internally in the DC fan to convert AC to DC Voltage to power the DC fan.

The Pros and Cons of AC fans

AC fans are commonly used because the AC outlets are readily available in our houses.

CON: Variable flow

The speed control of the AC Fans is not easy matter. The AC fan’s speed depends on the line frequency and partially on the amplitude of the AC Voltage source.

To change the frequency of the AC Voltage is totally not practical due to its very high conversion cost. To vary the amplitude and maintain the waveform of the AC Voltage source is also expensive and certainly not practical to meet the target cost of a speed-controlled AC fan.

Less expensive “Capacitor” speed control methods, influence the power factor of the fan. Finally, economical “Phase Control” speed control methods introduce electromagnetic noise.

CON: More energy consumption

AC fans do consume more energy than DC fans. You need up to $3 worth of electricity using a DC Fan and you need $10 worth using an AC Fan to achieve the same airflow result.

CON: More electromagnetic interference

AC fans have more electromagnetic interference than DC fans, when they use “Phase Control” speed control methods.

AC vs. DC: Which Fan Is Right for You?

The bottom line is that the right fan for you will depend on your specific needs. Prior to deciding between an AC and DC fan, you will need to carefully weigh the pros and cons of each type of fan.

Pelonis Technologies offers fan technologies for a variety of industries and applications. To evaluate which one is right for you, view our guide on how to select the right cooling fan for you.

If you need further assistance in choosing the right fan for your project and/or application, don't hesitate to reach out the Pelonis Technologies team and we'll be more than happy to assist you!

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A fan is a key component of any HVAC system. The most common HVAC fans are axial, forward-curved centrifugal, and backward-inclined, and each is uniquely suited to certain purposes. It’s important to understand each fan’s differences in energy efficiency, cost-effectiveness, and noise considerations. The wrong fan for the job could lead to reduced functionality and higher costs. Here’s what you need to know about the various fans for HVAC systems.

Axial Fans

Axial Fans, which include propeller, tube axial, and vane axial styles, move an air stream along the axis of the fan. These fans work like an airplane propeller—blades generate an aerodynamic lift that then pressurizes the air. Propeller fans embody only a motor and a propeller used to drive the airflow. Similar to a propeller fan, a tube axial fan includes a venturi that surrounds the fan propeller and is designed to reduce the air leak

age or vortices created by the spinning prop. A vane axial fan features vanes trailing the rear of the propeller, which straighten out the swirling airflow that occurs when the air is accelerated by the motor. Axial fans are inexpensive, compact, and light, making them a favorite for industrial applications. They are, however, usually noisier than centrifugal fans. Noise can be abated by insulating the duct; mounting the fan on soft materials like rubber or using a spring isolator to reduce the amount of transmitted vibration; or installation of sound dampening material or baffles.

Centrifugal Fans

Centrifugal Fans, which are categorized by their radial, forward curved, or backward inclined blade shapes, increase the speed of an air stream with a rotating impeller. The speed increases as the air reaches the ends of the blades and is then converted to pressure. These fans are able to produce high pressures, which makes them suitable for harsh operating conditions, such as systems with high temperatures or moist or dirty air streams. Tip vortices or tip leakage flow produced by the pressure differential across the airfoil section can be problematic with these basic fans.

Forward-Curved Centrifugal Fans, look more like hamster wheels and can create more air pressure. Because of this, they tend to be noisier than axial fans and require more power to run. They are durable, easy to clean and maintain, and have less problems with resistance. Forward-curved centrifugal fans are also called blowers.

Backward-Curved Centrifugal Fans are uncommonly shaped blades, which can be curved or straight, make these fans excellent for high volumes of airflow and variable resistance. They are often used for industrial purposes.

Applications of Fan Types

Though axial fans are usually the least expensive, they’re not the right solution for every situation. Because of their features and capabilities, they are best for compact electronics, automotive products, medical devices, and appliances as well as large applications such as cooling towers, vending machines, outdoor air conditioner compressors, and combustion engine cooling. Axial fans are also ideal as general-purpose fans.

Centrifugal fans are better for larger systems: air-handling units, air pollution and filtration systems, and drying systems. With incredible energy efficiency and versatility, these fans come in a variety of models, so you can find one to fit into a small, hard-to-reach space. They are also great options for dust collection, glass tempering, and incineration systems.

Choosing the right fan for your HVAC system is essential for its efficiency and performance. An axial fan, for example, won’t do as good a job managing the resistance compared to centrifugal fans of the same size in an air filtration system. Using an axial fan for that purpose would make the system perform poorly and likely lead to extra maintenance and repairs. Even though it would be less expensive initially, it would cost you more in the long run and would not function the way you would expect from such a system. Likewise, using a centrifugal fan in a cooling tower where it’s not needed would lead to unnecessary noise and increased costs.

Find the Perfect Fan for Your HVAC System Needs

Even among HVAC fan types, there are a variety of shapes and sizes that will help you narrow down the best option for your project. Take a look at our selection of fans listed in Pelonis Technologies' catalogue and see which one is right for you. If you’re still unsure on which fan is right for you, make sure to download our eBook, How to Select a Cooling Fan. Additionally, we can customize your choice to meet even the most demanding restrictions. If you have any questions or wish to learn more about HVAC system fans, contact our team today.

Crossflow fans are used to stop components from overheating in a wide variety of commercial and industrial products. These fans are typically long, narrow, and use rotating impeller blades to push a steady flow of cooling air over internal components inside protective product housings.

Our innovative new J Series Crossflow Fans provide a highly effective solution for products with limited space for cooling elements. This line of crossflow fans is specifically designed to meet the needs of applications that require:

• Low noise
• Operating efficiency
• Long service life

The Benefits of J Series Crossflow Fans

The J Series provides superior performance for cooling applications in tight spaces. Benefits of J Series Crossflow Fans include:

• Wide area cooling. J Series fans can be mounted horizontally or vertically to achieve maximum airflow coverage.
• Efficient operation. J Series fans feature Electronic Commutation, which reduces power usage, offers higher performance, and generates less heat.
• Direct or angled airflow. The flexibility of the J Series design enables airflow at 180°, 90°, or other angles necessary to optimize inflow and outflow.
• Speed monitoring and airflow control. Optional features include a tachometer and Pulse Width Modulation that enable users to monitor and control fan speed.
• Quiet operation. Fans in the J Series product line undergo precision balancing at multiple points throughout the manufacturing process to ensure minimal vibration and lower noise production.
• Long-term reliability. By using a heat-resistant aluminum alloy to produce J Series fans, we’ve ensured that fans won’t burn out due to temperature exposure in hot operating environments.
• Quality manufacturing standards. All J Series fans are manufactured and tested in accordance with ISO and ANSI/AMCA standards to ensure the highest quality performance and power usage.
• Custom designs. We can offer a range of customizations on J Series fans, including right/left motor positioning, modified lengths, stainless steel impellers, moisture and dust production, and more.

Conversion Charts for Crossflow Fans

The following conversion tables will help you to select the appropriate J Series fan for your application.

Static Pressure Conversion Table

Air Flow Conversion Table

Temperature Conversion Table

J Series Crossflow Fans from Pelonis Technologies

Pelonis Technologies provides a wide range of high-performance AC and DC fans and motors suitable for nearly any commercial or industrial application. For more information about our full product line, please visit our online catalog. To learn more about our innovative J Series Crossflow Fans, please download our eBook.

Brushless DC fans and blowers need optimal motion control. When complex or demanding applications need precise levels of output, intelligent motion control systems can keep parts safe while still ensuring high-quality production cycles. These intelligent motion controls (IMCs) have in-board circuits that use programmable, information-gathering features to develop air movement “intelligence” and learn how the parts need to operate in different environments.

IMCs are ideal for:

• Green applications in which facility managers want to improve reliability, the equipment’s life expectancy, and energy efficiency.
• Systems that need consistent monitoring and cooling—IMCs have multi-alarm connections to prevent complete system failures, reduce voltage fluctuations, and have more reliable control.

When businesses install IMCs, they will make their facilities greener and more efficient. Read on to learn about all the different benefits IMCs can bring.

Top Solutions

There are several different types of IMCs that can add control to the operation and maintenance of brushless DC fans and blowers. The top four IMC solutions are:

Rotation Detectors

A smart rotation detector can monitor fan operations in parallel circuits to detect ongoing circulation as well as potential failures or stopped fans. These systems give a “high” output signal to the monitoring interface while the fan rotates. That same signal turns to “low” or “off” based on the fan’s status. This allows operators and maintenance teams to investigate potential problem areas more quickly because the system automatically notifies them when a fan stops working rather than requiring them to monitor changes in temperature.

Rotation detectors use the same hardware as the frequency generator (tachometer), which we also describe below. Once the detector is added to an array of fans, it operates as part of the facility’s multi-alarm connection.

Inrush Current Protection

When motors, heating elements, transformers, and power supplies turn on, the current surges. This short-lived inrush current can damage electronic parts if it isn’t properly controlled.

Facility managers use inrush current protection to slow the flood of current to the equipment. This technology allows fan blades to speed up at a more gradual rate through incremental increases of current. The process takes approximately ten seconds during startup, and it protects both the circuits and the moving parts from damage.

Auto Start

Sometimes, fan blades get blocked by temporary obstructions. Auto starts control the current output in these circumstances. First, the current can be reduced to zero when an obstruction is detected so the fan blades don’t damage themselves. This feature is called locked rotor protection. Then, the auto-start control uses a second feature, restart with current limit, to guarantee the restart of the rotor once it is released.

Frequency Generator (Tachometer)

This IMC solution is an open collective output type that produces an analog voltage based on the fan’s motor speed. These parts provide feedback and can be used to measure the speed of motors, rotors, and engines.

Frequency generators use the same hardware as rotation detectors, and they’re powered by the power supply voltage. A tachometer will send a square wave signal to the reading device if the collector connects with a pullup resistor. This part can handle a maximum collector voltage of 72 V DC and current of 10 mA.

Quality IMC Solutions from Pelonis Technologies, Inc.

Smart IMC solutions keep your equipment’s DC blowers and fans operating at their full potential. These tools also extend the lifespan of your equipment and protect electronics from the dangers of overheating.

Pelonis Technologies, Inc., provides a wide array of fans, blowers, and other cooling and heating solutions. Contact our team to learn about our customization services or to browse our design catalog.