FAQ | HVLS Fans | Arbon
Q: Why do Rite-Hite HVLS Fans have fewer blades than other HVLS fans?A: It is the shape, not the number of blades that generates the large volume of air movement needed for an effective HVLS fan. Maximum air volume is delivered when there is a consistent amount of air movement across the entire diameter of the fan. Our Propell-Aire™ Blade Design has a complex contoured shape that varies along its length. This blade design is impossible to produce by extrusion. Extruded blades do not provide this efficient, consistent air movement, and they require a greater number of blades to help compensate. Our Propell-Aire Blades are lighter, better balanced, and safer to install than extruded blades.
Q: Why are the blades tilted up when the HVLS fan is not rotating?A: This tilt allows our HVLS fans to deliver the greatest amount of air over an area up to 85 feet (26000 mm) from the fan’s center in all directions. It creates a more conical air movement below the fan and raises the height of the horizontal air stream away from the fan’s diameter to about four to six feet (1200 to 1800 mm), providing more effective cooling.
Q: Why do the blades lift higher during operation?A: Like the blades of a helicopter, a combination of centrifugal force and air pressure causes the blades to move upward during operation.
Q: Do the hubs and blades of Rite-Hite fans need to be balanced?A: Similar to the tires on your vehicle, Rite-Hite HVLS Fan hubs and blades are “balanced”. They are ideally suited for your industrial fan application and will never require adjustment.
Q: What secures the blades to the hub of a Revolution HVLS Fan?A: Each blade is attached to the hub in two specific ways; the blade is seated into a secure position on the hub arm and then locked in with a bolt that is tightened with a torque wrench to 200 foot-pounds (Revolution, Revolution 150/75 Series) or 75 foot-pounds (Revolution 25 Series).
Q: What is done to strengthen the connection between the blade and hub?A: A vibration-absorbing bushing is used to reduce the stress by 50 to 75%. This design has been used for over 40 years in applications generating more than 10 times the stress of our Revolution HVLS Fan, and allows us to be confident providing the 10-year structural integrity warranty on the blade-to-hub connection.
Q: How does air circulate below and outward from Rite-Hite HVLS Fans?A: Air is pulled from above an HVLS fan and pushed down in a conical shape to the floor below. Air travels in this cone shape until it hits the floor and then moves in a horizontal stream away from the diameter of the fan. The fan will move air, up to 85 feet (26000 mm) for the Revolution, 150 Series and 75 Series and up to 75 feet (15200mm) for the 25 Series, from the fan’s center in all directions.
Q: How is a Rite-Hite HVLS Fan’s airflow different from other large HVLS industrial ceiling fans?A. Many other large industrial HVLS fans have extruded blade designs, which results in an area directly underneath HVLS fans where you feel little, if any, air movement. These “holes” exist because an extruded blade does not move air uniformly across the full diameter of the fan. These “holes” do not exist with a Rite-Hite Fan because our blades are not produced by extrusion, which is an important benefit for many applications.
Q: What is the wing on the end of the blade?A: The vortex technology (VT) tips reduce the noise from the moving air. These tips also increase the fans efficiency by decreasing air movement over the tip of the blade.
Q: What direction does a Rite-Hite HVLS Fan rotate?A: Rite-Hite HVLS Fans should rotate clockwise when you are standing below the fan, looking up. The fan is not harmed by running backwards; it simply is not as effective.
Q: What safety features are built-in to the design and installation of a Rite-Hite HVLS Fan?A: Redundant safety features are present on all Rite-Hite fan designs.
Revolution 4-Blade Fans
- Feature a three-way motor-to-hub safety connection
- Four stabilization cables from the motor housing to the ceiling, limit vibration and provide added safety
- A unique safety ring is provided for back-up security for the motor to hub connection. Each hub “blade arm” is connected to the safety ring.
Revolution 150, 75 and 25 Series – Direct Drive Fans (3-Blade Fans)
- Four stabilization cables from the motor housing to the ceiling, limit vibration and provide added safety
- The hub arms are interlocking and attached to the motor with (12) grade 5 bolts (Revolution 150 and 75 Series)
- A unique safety bracket extends below the hub. A safety cable is attached through the motor housing to the drop tube
Q: How do I know what size HVLS fan is needed?A: Size does matter when placing HVLS fans. Larger diameter industrial fans will move air further down rack aisles and over some obstructions. Smaller diameter industrial fans can be most effective in specific work areas or where installation space is limited.
Air velocity will vary throughout the zones depending on the fan’s diameter and speed setting. When used for cooling people, choose an HVLS fan that moves air at a minimum of 2 mph in the targeted zone. Whereas, the minimum air speed needed for destratification is 1/2 mph. Consult the air speed charts for specific air speeds in each fan zone.
Q: What is the return on investment for the colder months?A: HVLS fans equalize the temperature in a building by moving warmer air trapped at the ceiling down to the floor, making the building’s temperature more uniform. This process is called destratification and supplements the heating system by moving warm air to the floor, where it is needed. This can save up to 30% in heating costs and a typical payback period is 6 months to 2 years.
Q: What is the benefit of using HVLS fans during warmer months?A: The increased air movement caused by a Rite-Hite HVLS Fan and its evaporative cooling effect can make the air feel up to 18°F cooler. Many studies prove that comfortable employees are more productive, and have better morale. A NASA study on heat stress reports that at an 85°F effective temperature there is an 18% loss in work output and a 40% loss in accuracy.
Air speed produces a wind chill factor, which gives a person the sensation of being exposed to a lower temperature than the actual measured temperature. For example, an employee working at a high activity level in an environment with a constant temperature of 60°F with an air speed of 4 mph, will “feel like” it’s only 73°F vs. “feeling like” 91°F with no air speed (University of California Berkeley).
Q: How does a Rite-Hite HVLS Fan help with drying moist environments?A: Moving air over moist floors, racking, or products, will help to dry them and help prevent moisture from accumulating. The amount of moisture removed depends on the humidity of the air flowing over it. HVLS fans help prevent the phenomenon known as Sweating Slab Syndrome (SSS) which occurs when moisture collects on a surface (usually concrete), creating slippery conditions that pose a danger to workers, equipment, and products.
Q: Should a Rite-Hite HVLS Fan run backwards in the wintertime like my ceiling fan at home?A: In our homes we have been told that we need to run our fans during the summer in a certain direction so we can feel the air to create a cooling effect; in the winter, the fans should be run in reverse to circulate air but without feeling much air movement. This works in our homes because the blades are flat paddles that are not affected by the direction the fan is spinning. On Rite-Hite HVLS fans, the blades have more of a curved airfoil shape that is designed to move air downward. These fans can also run in reverse but they are less efficient at pulling air upward than they are at moving air downward. We recommend running the fans clockwise (forward) very slowly in the winter so they are still moving the warmer air down from the ceiling while feeling very little airflow. The energy consumption at this speed is also very low. During the summer, fan speeds can increase to create more airflow and an evaporative cooling effect.
The fans will not be damaged by running in reverse; they are just less efficient in moving air. We have recommended that our fans run in reverse for a few customers that wanted to increase air movement in areas such as welding cells without dispersing the welding gas, or in other sensitive areas where there was concern about the movement of very fine dust.
Q: What is the recommended spacing for Rite-Hite HVLS Fans?A: There are multiple variables that are taken into account when placing an HVLS fan. Consult Rite-Hite Fan Applications (or your Rite-Hite Fan Representative) for more information.
Q: How much clearance is required above a HVLS Fan?A: Because HVLS fans use the air from above the fan, there is a minimum clearance required between the mounting surface and the roof surface.
HVLS fans pull the air from above them and push it to the floor. As the air above the fan is pushed to the floor, surrounding air from the ceiling rushes in to fill the void. If air is restricted in moving above the fan because the fan is mounted too close to the ceiling, or there are other obstructions, the output of the fan will be limited. The extra height required above a fan is dependent on the fan drop height, fan diameter and fan model. See the owner’s manual for more information.
If a ceiling support structure is an open-web design, all hanging dimensions can be taken from the underside of the ceiling. If the ceiling’s support structure is a solid beam or solid channel, all measurements must be taken using the bottom of the beam as the basis point for the hanging dimension. If the roof is pitched, this must also be accounted for above the tips of the blades. Failure to follow these guidelines will result in limited air movement by the fan.
Q: What if the minimum distance to the ceiling deck is not available?A: There are several options available. Consult Rite-Hite Fan Applications for more information (or request a site survey from your Rite-Hite Fan Representative).
Q: Will obstructions below a fan disrupt the airflow created by a Rite-Hite HVLS Fan?A: Yes. Air movement is blocked by solid objects. The more open the area is around the fan, the better the airflow will be.
Q: How close can you mount an HVLS fan to obstructions like mezzanines or racking?A: The closer you are to obstructions, the more turbulent the air is. Air will bounce off things in close proximity and cause turbulent air movement that will affect an industrial fan’s performance. When possible, keep blade tips at least one fan diameter from walls or solid obstructions.
Q: What do you need to be aware of when placing HVLS fans in buildings protected by sprinklers?A: The National Fire Protection Agency has updated the 2013 Edition of NFPA 13: Standard for the Installation of Sprinkler Systems. The Standard now includes specific installation requirements for HVLS fans. This update applies to all manufacturers of HVLS fans.
The new application information is listed in Chapter 11 (11.1.7) which covers Design Approaches and Chapter 12 (12.1.4) covers General Requirements for Storage. The text is identical in both chapters and is written below for your convenience.
High Volume Low Speed (HVLS) Fans. The installation of HVLS fans in buildings equipped with sprinklers, including ESFR sprinklers, shall comply with the following:
- 1. The Maximum fan diameter shall be 24' (7.3 m)
- 2. The HVLS fan shall be centered approximately between four adjacent sprinklers
- 3. The vertical clearance from the HVLS fan to sprinkler deflector shall be a minimum of 3 ft. (0.9 m)
- 4. All HVLS fans shall be interlocked to shut down immediately upon receiving a water flow signal from the alarm system in accordance with the requirements of NFPA 72
- 5. The air speed over the sprinklers in this position will be less than 1 meter/sec.
All Rite-Hite HVLS Fans have the ability to receive a low voltage stop command from the alarm system, which addresses issue #4 above. Please consult Rite-Hite Fan Applications with any specific questions on this issue.
Q: How important is air speed when applying fans?A: Air speed is the most important criterion for specifying a fan for cooling. The air speed is what people will feel when the fan is running. It is also what will help provide the evaporative cooling effect (when the moving air interacts with the perspiration on our bodies to help keep us cooler).
Q: Why do people talk about CFM as a performance criterion?A: CFM is a measurement of volume (cubic feet per minute). This term is used because it is the result of AMCA 230 – a fan testing standard. This standard started as a standard to test small fans that would typically be used in walls and ceilings. It was adapted to also be used for large HVLS fans however, the method for determining performance for the larger fans is quite different. The fan is weighed while it is running to determine the force the fan is imparting on the surrounding air. This standard does not account for inefficiencies in blade design or horizontal components of the airflow. There have also been several changes in this standard that cause the results to vary significantly. If these numbers are referenced, you should be aware of what version of the standard was used for testing. These could be either ANSI / AMCA 230-99, 230-07, or 230-15.
Q: Which fans would work best in a wet or dirty environment?A: The Revolution (gear motor) fan would be a better choice for this environment because the motor is totally sealed.
Q: What is the overall shipping weight?A: Please see the Owner’s Manual.
Q: What planned maintenance is required?A: Minimal planned maintenance is required. Please see the Owner’s Manual.
Q: What are the details of the warranty?A: The Rite-Hite Fan warranties are:
- Lifetime warranty on the workmanship of the blades and hub
- 1-year Customer Satisfaction Money-Back Guarantee
- 10-year structural integrity warranty
- 3 years parts and 3 years labor on all components
Q: What are the advantages of a direct drive motor over a gear motor?A: A gear motor uses a gearbox to decrease a normally faster motor speed while increasing torque at the output shaft. A direct drive motor will not have a gearbox but will use electronics to create similar output torque. A direct drive motor has the advantages of having reduced noise (motor is nearly silent), no potential for oil leakage and there are less moving parts because the gearbox has been removed. In many cases, the direct drive motors are designed and wound for very specific requirements.
Q: How do energy efficiencies compare between direct drive motors and geared motors?A. Since the change was made to IE3 motors several years ago on the gear motor design, the energy efficiency is very similar between direct drive motors and gear motors.
Q: How is the wiring done for fire protection or temperature probes?A: Externally available connections eliminate the need to open the controls enclosure. External connections are also present if there is a need to hard wire the connection to the Fan-Commander 2.0.
Q: Why do the direct drive fans take significantly less time to install?A: Fans ship preassembled and factory configured for each application. Pre-wired fans and wireless controls allow cooling to begin almost immediately.
Q: Why is there a different blade design for the Revolution 150 Series, 75 Series and the 25 Series?A: The Revolution 25 Series is available in sizes from 6 to 12 ft. in diameter. The blades are single material thick. This fan is intended to be used in smaller spaces.
The Revolution 150 and 75 Series are available in larger sizes, up to 24 ft. in diameter. The blades are formed and welded to have an airfoil shape that helps move more air over larger spaces.
Q: Can you swap out different diameter blades for a direct drive fan that is already installed?A: Each fan is built to order, and factory configured for the desired blade size as well as mounting height and blade design. If blades are changed at installation, program changes will be required for the fan to run properly.
Q: Are there different mounting options available?A: Yes. Each fan can ship with one of four available mounting options. The ceiling structure will determine the most appropriate mounting option. Consult Owner’s Manual for additional details.
Q: What are the options for ordering fans in different colors?A: Yes. Fan blades and hub cover can be painted any RAL K5 color.
Q: Are the Revolution direct drive fans also considered brushless fans?A: Yes. Brushes are used for mechanical commutation on some DC motors. Brushes are a wear part that must be replaced periodically. The Revolution 25/75/150 utilizes a sensorless PMSM (Permanent Magnet Synchronous Motor). All motors of this type are "brushless." The Revolution Fan motor is maintenance free.
Q: Why does the smaller Revolution 25 Series Fan have higher air speeds compared to the Revolution 150 and 75 Series Fans?A: Air speeds are often faster for the smaller (25 Series) fan but the larger fans (75 and 150 Series) will still move more air. The direct drive fans use the same motor regardless of diameter. Since the 8' blades "scoop" less air there is less resistance on the blades, allowing the fan to spin faster. This means it will move less air at faster speeds. Whereas, the 24' fan scoops more air. Since there is more resistance on the blades, it spins at a slower speed. This means it will move more air, just at slightly different speeds.
Q: What are the high voltage electrical requirements for the Revolution Direct Drive Fan installations?A: Each fan is provided with a standard NEMA twist lock plug for ease of electrical installation and service disconnect. The fan will be plugged directly into the twist lock receptacle, which will have been installed by an electrician prior to the fan installation. All fan high voltage electrical functions are prewired at the factory. Please consult the Owner’s Manual.
Q: What low voltage wiring will be required?A: All fan controls will be wireless. Please see the Installation and Owner's Manual.
Q: Is there potential for interference from Wi-Fi Networks?A: No. Wi-Fi is not a problem. Traditional Wi-Fi operates at 2.4 GHz (a/b/g). Newer (n) Wi-Fi is 5.8 GHz. Our radios operate far below these bands at 0.9 GHz.
Q: What is the IP Rating?A: The IP Rating for the geared Revolution fan is 55. The IP Rating is 40 for the Fan-Commander 2.0 and all of the direct drive fans.
Q: Is there potential for interference from RFID or other systems a customer may be using?A: Sometimes there is an overlap in band use from RFID devices within a facility. Our controls employ Frequency Hopping Spread Spectrum (FHSS) and will automatically shift the network traffic to an open channel (64 channels available) if it detects radio interference on the active channel.
Q: Will building structures/obstructions block signals?A: Obstructions may reduce signal strength but signals will pass through walls (dry wall, cinder block, metal sheeting, and concrete), racking, and equipment. Our controls use longer wavelengths than systems like Wi-Fi or Bluetooth, which means they are better able to pass through walls.
Q: What range needs to be considered if a signal needs to pass from one fan to another?A: We can stretch 400' between fans in a "typical" industrial environment. It is also possible to install signal boosters between fans if the signal is weak.
Q: What functions are on the control station of a Rite-Hite HVLS Fan?A: Each Revolution ceiling-mounted HVLS fan, or group of fans, comes standard with a touch screen controller (Fan-Commander 2.0) and is capable of operating up to 24 fans. It also allows the fans to be controlled based on schedule or temperature. Because all of the high voltage components are mounted on the fan, troubleshooting will also be done from this control station.
Q: Can the fans be controlled by a Building Management System?A: Yes. Please see the Owner’s Manual.
Q: Can the Fan-Commander 2.0 connect to an IT network?A: Ethernet is standard on all Fan-Commander 2.0 controls. Ethernet connectivity allows the controller to be connected to a user's local IT network. Once connected, maintenance or facility managers can monitor and control all of the fans in the system from their PC or mobile device (Windows, Android, iOS, macOS, Linux, Raspbian), onsite or off site. This connectivity will allow you to monitor which fans are running, monitor ambient temperatures around the plant, access diagnostic parameters, change fan speeds, or start/stop fans.