LED Lighting Supply / Blog / HVLS Fans: A Comprehensive Buyer’s Guide

HVLS Fans: A Comprehensive Buyer’s Guide


High temperatures, humidity, and adequate ventilation can be one of the most significant challenges for an industrial or commercial building to overcome. These structures typically consist of high ceilings and open-concept floor plans that make it difficult for cool air to naturally circulate.

HVLS fans are an efficient, highly effective solution for improving interior environmental conditions in these buildings. By understanding the applications of this product, how they work, and their various benefits, sizing options, and specifications, a consumer can ensure that they’re selecting the perfect fan for their building’s airflow needs.

What Does HVLS Stand For?

HVLS, or high volume low speed, is a type of fan commonly used in industrial settings where powerful airflow is necessary. Compared to smaller residential fans, HVLS fans spin at a much slower rate- normally no more than 200 RPM.

While a lower RPM may suggest less effective operation, the opposite is experienced. This is due to the large diameter of HVLS fans. These fans can range from 7 feet to 20 feet or more, making them ideal for large open spaces.

The combination of a large diameter and slow motor rotation results in a larger CFM (cubic foot per minute) – the unit of measurement that quantifies the volume of airflow. At the same time, it also results in less horsepower being used.

Applications for HVLS Fans

HVLS fans are most commonly utilized by industrial and commercial businesses that operate in large, open-space facilities. These facilities can be too large to regulate ambient temperatures with standard HVAC systems, and thus require a more efficient and practical solution. Some of the most common applications include:

  • Manufacturing: Manufacturing facilities are filled with machinery that generates heat. HVLS fans can adequately disperse this heat, helping employees feel more comfortable and equipment operate more efficiently.
  • Warehouses: The expansive, open nature of warehouses results in extreme air stratification which can be resolved by the installation of multiple HVLS fans.
  • Agricultural Buildings: HVLS fans can help regulate the internal temperature of barns and other agricultural buildings, making it safer and more humane for both livestock and employees.
  • Gyms and Athletic Facilities: Large-scale gyms and athletic facilities like basketball courts can be difficult to thermally regulate. HVLS fans can efficiently cool the building while also assisting athletes with sweat evaporation.
  • Aviation Hangars and Equipment Garages: High-bay garages that house aircraft, busses, and other large vehicles are notorious for trapping heat. A well-planned fan installation can reduce this heat and eliminate the need for costly AC systems.

 

How do HVLS fans work?

To first understand how HVLS fans operate, it’s important to understand the basic principles of how fans work. The cooling effect that’s experienced by fans is a result of two scientific processes – convection and evaporation.

Convection can be simply described as the movement and transfer of heat, with the tendency for warm air to rise and cool air to sink. Fans accelerate the convection process and move air more rapidly, creating a forced convection cycle where the heat that is around an individual’s skin is removed and replaced with cool air. Increased airflow also expedites evaporation, helping to remove sweat from the skin and subsequently cool the individual.

This continuous process of convection and evaporation is made possible through destratification and the interaction between a vertical air column and a horizontal floor jet.

Destratification

The tendency of warm air to rise and cool air to sink causes the stratification, or organized separation, of air layers in an enclosed space. HVLS fans work to remove these layers by circulating airflow and causing warm and cool air to mix. A visual representation of how HVLS fans destratify air can be found below:

Impact Of Destratification On Facility Temperature

Destratification Impact On Floor And Ceiling Temperatures

Air Columns and the Horizontal Floor Jet

Increasing Facility Air Circulation With Hvls FansAs a ceiling-mounted fan’s blades spin, they produce a vertical column of air beneath the fan. When this column reaches the ground, the air spreads out sideways, creating what is known as a horizontal floor jet.

When the horizontal floor jet reaches walls or other obstructions, it naturally rises back to the ceiling and is cycled through the air column once again. This creates an endless cycle of destratification, convection, and evaporation – all of which help to cool a space and the people inside. It’s important to note that this cycle is only possible when a fan is mounted at the top of a space, preferably the ceiling for maximum effect.

In general, an HVLS fan’s air column and horizontal floor jet will create a direct breeze zone that is equivalent to four times the diameter of the fan. For example, a 12-foot fan will produce a noticeable effect on a 48-foot circular zone.

Technical Design of an HVLS Fan

LED Lighting Supply’s HVLS fan blade design is specially constructed to enhance cooling through larger air columns and larger horizontal floor jets. This is facilitated by two distinct features: twisted and tapered blades, and longer blades.

Tapered Fan Blades

Due to the principles of angular velocity, the end of a fan blade will always spin faster than the area that’s closer to the center. Our fans compensate for this by tapering the fan’s blades and making them gradually thinner towards the outer edge. This equalizes the rotational speed between the center of the fan and the end of the blade, resulting in a more consistent and uniform air column. In turn, this reduces the need for a fan to work at a higher RPM, resulting in more efficient usage.

Our fan blades are also surprisingly lightweight. This allows a smaller horsepower motor to be used, resulting in greater energy efficiency and ROI for customers.

Longer Fan Blades

The size and height of a horizontal floor jet are directly proportionate to the size of the air column, and the size of an air column is directly proportionate to the diameter of the HVLS fan. This relationship is the main reason why large HVLS fans are so effective, as smaller fans do not have the power that’s necessary to create the same level of cooling.

Our fans are intentionally constructed to use longer blades, resulting in larger air columns and horizontal jets that improve air circulation throughout a facility.

Benefits of an HVLS Fan Installation

As demonstrated, HVLS fans are extremely effective at cooling large spaces, particularly ones where air stratification is a concern. While comfortable temperatures are an obvious advantage, there are several other benefits of HVLS fans, including personal well-being, safety, energy efficiency, and financial cost savings.

Fan Destratification Impact On The Feels Like Temperature

Interior Comfort

Manageable temperatures are crucial for a comfortable and enjoyable workplace. By installing HVLS fans in a facility, employees will feel happier and more appreciated. The lower RPM of HVLS fans also results in less environmental noise, which improves interior conditions. When conditions are comfortable, employees work more productively and customers are more satisfied.

Health and Safety

Workplace and patron safety should be a concern for all business owners. OSHA recommends that temperature control be in the range of 68-76℉ and humidity control in the range of 20%-60%. Installing an HVLS fan will not only keep a building habitable but also safe and up-to-code according to federal regulations.

Humidity control is essential for preserving the health of occupants and the health of the building. When moisture goes unchecked, mold and mildew can begin to develop in hidden areas. If ignored, these particles can damage structural components and compromise individuals’ respiratory function.

Easy Installation

With a single NEMA 1 enclosure, all fuse disconnects, variable speed drives, and terminal blocks are consolidated into the HVLS fan control cabinet. This “all-in-one” design makes installation straightforward for contractors, as wiring only has to be run to the cabinet and the fan.

Energy and Cost Savings

In many regions of the world, extreme heat and cold can be a challenge for commercial building owners. The costs of maintaining and operating an HVAC system in these large structures can be enormous, especially with rising energy rates.

HVLS fan power consumption is significantly less than commercial HVAC, providing an impressive ROI for building owners. These fans can either be installed as a complete replacement for HVAC, or as a way to reduce HVAC loads.

Tax Incentives

In addition to an HVLS fan’s energy savings, the Inflation Reduction Act of 2022 incentivizes commercial buildings to invest in energy-efficient appliances and equipment that reduce annual energy costs. This includes products like interior lighting systems, and heating, cooling, and ventilation systems, meaning HVLS fans qualify.

Some key aspects to know about this tax incentive include:

For energy-efficient commercial building property (EECBP), the HVLS fans must be part of a certified plan to reduce the building’s total annual energy and power costs by 25% or more.

The deduction is equal to the lesser value of either:

  • The cost of the installed equipment

OR

  • $0.50 per square foot for a building with 25% energy savings
  • Plus $0.02 per square foot for each percentage point of energy savings above 25%
  • Up to a maximum of $1.00 per square foot for a building with 50% energy savings

It is a tax deduction, not a tax credit. This means that the cost of an HVLS fan can only be used to reduce taxable income, not tax liability.

How to Determine HVLS Fan Sizing

When purchasing an HVLS fan, sizing is absolutely crucial. Selecting the wrong size fan can result in many problems, such as insufficient airflow, an improperly fitted fan, or an illegal installation. By carefully reviewing the factors below, a consumer can ensure that they’re getting the perfect fan for their application.

Physical Dimensions

The physical dimensions of space should be the first consideration to make. Calculate the overall footprint of usable ceiling space and determine how many fans can realistically fit. Be sure to consider the various fan sizes that are available, such as 8,12,16, or 20 ft.

It’s also important to adhere to manufacturer recommendations, as each fan size requires a certain distance between itself and others.

Mounting Height and Clearance

The larger a fan is, the higher it can be mounted to remain effective. Typically, an ideal mounting height for an HVLS fan is between 20-30 feet, but it can still be useful as low as 10.

Ensure that there is enough clearance below the fan to accommodate any large equipment used in the facility, such as forklifts, shelving, man lifts, and scaffolding.

Site-Specific Requirements

Many building sites have unique requirements that must be accounted for when designing a fan installation. For example, certain structures have sloped roofs that will require an extension mount for proper airflow. Others may have interior obstructions that have to be worked around, such as HVAC ductwork, light fixtures, and wire drops for machinery.

Furthermore, fans generally only need to be installed in areas of the building where workers or customers are present. Coverage calculations should be made only using these area dimensions.

Building Codes

Local building codes need to be followed when installing HVLS fans. Distance from the wall, the ground, and the electrical draw should all be considered. Building codes also require certain CFM values which are based upon square footage and the number of occupants within a space.

HVLS Fan Square Foot Coverage Area and the Number of Fans

When calculating how many fans a facility needs, it’s important to consider more than just the maximum number that can fit. The powerful nature of HVLS fans makes them very effective over large coverage areas, and often only a few fans will be necessary.

Each fan size has different square footage specs (shown below), so carefully compare the building’s dimensions and square footage to find the ideal number of fans.

HVLS Fan Comparison

Fan Size (ft.) 8 12 16 20
Max. Coverage Area (sq. ft.) 4,250 8,500 12,750 19,750
Fan Spacing (ft.) 42 63 84 105

Existing Climate Control Systems

HVLS fans can be integrated with an existing HVAC system, or they can be installed in a facility that lacks HVAC. When adding fans, consider what the building’s goals are:

Are you looking to reduce the use of an HVAC system by 50%?

Do you want to replace its usage entirely?

Will the HVLS fans be used to boost the existing HVAC’s performance?

By identifying these goals, a determination of the correct number of fans and their size can be made.

Additional Features and Components to Consider

Once the size and number of fans have been decided on, businesses should consider the various additional options that are available. At LED Lighting Supply, we offer a variety of add-on features, details, and components that can be selected to better suit customer’s needs.

Customizable Colors

Industrial and commercial fans don’t have to have a boring and sterile aesthetic. Our inventory of fans comes in eight different stock color options, allowing customers to design a fan array that complements their facilities’ interior. Choose from black, white, green, yellow, brushed aluminum, blue, or red.

Mounting Kits

Buildings have different structural requirements when it comes to fan mounting. We offer a variety of options to help our customers integrate their new fans with minimal effort, such as standard I-Beam, Z-Purlins, and open joist mounts. We also carry 3 ft. and 6 ft. extensions for buildings with exceptionally high ceilings.

Control Units

Every fan at LED Lighting Supply comes standard with a single fan control unit. We also have multi-fan control units (limited to 4 fans/unit) and remote, key-lockout control units that are ideal for public settings where access to the fan control needs to be secured.

There are also a variety of voltage/phase options for different electrical architectures. 230v/single phase is used most frequently, but 115 volt, 460 volt, and three-phase power systems are also available. Output power from the control unit to the fan will always be three-phase.

Tether System

Some commercial buildings are partially exposed to the outdoors and can encounter adverse weather conditions, such as high winds. Every HVLS fan can be equipped with a patented tether system that makes it safe to use in these demanding work locations.

General Guidelines for HVLS Fan Maintenance

Once a fan has been purchased and installed, keeping up with regular service will ensure a high HVSL fan ROI. These fans rarely require repairs or part replacements, and the double-reduction helical gearbox found in most HVLS units will never require maintenance or lubrication.  Additionally, HVLS fan frames are constructed of heavy-gauge, powder-coated steel that is corrosion-resistant for maximum durability.

Despite the durable and trouble-free nature of these fans, surface-level maintenance can still go a long way toward preserving performance. Some common preventative tasks are displayed in the chart below.

Task Purpose
Visual Inspections Cursory visual inspections are great for identifying any damages like housing cracks and bent blades.
Hardware Inspections An up-close hardware inspection gives a technician the opportunity to check the torque of fasteners and mounting hardware and to make sure nothing has come loose.
Wiring and Electrical Inspections Inspecting the wiring and electrical connections can be helpful for finding frays, excessive tension, or wrapped cordage.
Cleaning and Lubrication Leak Checks Removing dust from fan blades and checking for oil leaks in the control unit are essential for long-lasting functionality.

Enhance Cooling and Airflow with Help from LED Lighting Supply

High volume low speed fans are a staple for industrial and commercial buildings that require the highest level of ventilation, airflow, and environmental control. Their installation can provide countless benefits for a facility including the health and comfort of occupants, significant operational cost-savings, and improved energy efficiency.

LED Lighting Supply is proud to manufacture high-performance HVLS fans in a range of sizes, giving customers the flexibility to choose a fan that perfectly suits their business. Browse our complete inventory of fans and commercial lighting solutions, and contact us today to learn more about any product.

Frequently Asked Questions

Do HVLS fans need a local disconnect?

The necessity of a local disconnect is completely dependent upon local regulations and relevant NEC electrical codes. However, a disconnect is a great idea for HVLS fans and fire protection, as it allows the device to be manually turned off in case of an emergency.

How to prevent light strobing with HVLS fans?

Light strobing can be prevented by maximizing the vertical and horizontal distance between the fan blades and the light source. When possible, avoid overlapping the fan and the light source, and avoid using recessed light fixtures.

When should an HVLS fan be run in reverse?

While some HVLS fans can be run in reverse, it’s generally an inefficient way to circulate air. Running a fan backwards minimizes the evaporative cooling effect in the summer, and requires immense energy for destratification in winter.

Can HVLS fans reduce moisture from under the ceiling?

Yes. HVLS fans circulate and mix air from both the top and bottom of a building. This circulation keeps the air moving and prevents moisture from forming due to convection and evaporation.

Are HVLS fans quiet?

Compared to residential, direct drive fans, HVLS fans do produce more noise. However, the low-HP gear drive motor found in an HVLS fan produces significantly less volume than other commercial fan styles. In an industrial setting, this slight amount of noise is negligible.

How long will it take to receive an HVLS fan?

At LED Lighting Supply, our lead time is approximately 2-3 weeks.