Nothing is as important as the air we breathe but managing IAQ can be demanding. High-volume-low-speed fans are specially made to destratify and mobilize large volumes of air in any space. This makes HVAC systems to function more productively while optimizing comfort and health in all conditions.
Before we dig in deeper into the article, it is important to know what exactly we are talking about.
What are HVLS fans?
Technically, an HVLS fan is a ceiling fan which is bigger than 7 feet (2.1) in diameter. As opposed to a small, high velocity fan that generates small, turbulent air channels which disperse in a short period of time, HVLS fans majorly rely on size rather than on speed to move a specific amount of air. Earlier, these fans were originally designed for large commercial workplaces such as factories and barns but as the technology evolved, their use extended to other small scale workplaces as well. They can be found in a wide variety of industrial, commercial and residential spaces often working jointly with HVAC systems for energy saving purposes. It can also be noticed energy friendly HVLS fans have now managed to take over leading roles in the green building movement.
In short, these fans are the perfect fit for large facilities while keeping the workers and employees cool and comfortable.
HVLS fans are manufactured to hang from the ceiling with no cords which accounts for safe environment by avoiding trip hazards. This is an important factor considering many plants and facility managers have identified cords as one the most popular workplace hazards. It cannot go unnoticed that the overall direct interaction between an employee and a fan is reduced to fair degree with various HVLS models. This feature is compounded by the maintenance free aspect of direct-drive motors which reduces the risk of oil leakage.
Now, there are different types of HVLS fans. Different facilities use different fans which falls under the criteria of their requirements. Some HVLS fans come with gearbox motors while some have direct drive motors. Direct drive motors are less noisy and have efficient maintenance and workability systems. They have fewer parts and hardware but provide optimum performance. They are also less expensive.
Next question which might come into your mind is about their functionality.
Features of an HVLS fan
Earlier, engineers focused more on the fan speed and less on efficiency and productivity. Many of us agree that cool air feels good on a hot sunny day, you also need to be careful about excessive air circulation. Today, engineers design HVLS fans to reduce too much air movement which could otherwise cause technical problems.
HVLS fan blade wingspans range from 7 to 24 feet and move large volumes of air with minimal energy utilization per square foot, lowering costs and increasing comfort. Moreover, HVLS fans installed in buildings have experienced less absenteeism, less employee complaints and a rise in productivity and performance.
Buildings with high ceilings tend to experience high amounts of heat stratification in winter where warmer air rises to the ceiling and cooler air sinks down towards the floor level. This mechanism causes a facility’s heaters to work two to three times harder to keep employees and buildings residents warm while most of the heat continues to be trapped above in the air. According to an estimate, air temperature can increase 0.5 to -1.5 degree per foot in ceiling height. This means that if it is 65 degrees on the floor, it could reach up to 85 to 90 degrees at the roofline. HVLS fans perform air circulation so that warm air trapped at the ceiling is brought down to floor level.
A building’s indoor air quality and temperature are crucial factors that influence everything, be it heating bills or employee’s health. HVLS fans offer great solutions to improve indoor air composition and increase a facility’s efficiency, comfort and savings.
How do HVLS fans work?
The air from the HVLS fan moves towards the floor in a column in all directions moving horizontally until it reaches an airlow or some other blockage. At this point, the air turns upwards and flows back towards the fan.
Here comes the theory of convection like air currents that build up as the air continues to spin. This increased air circulation constantly removes hot, humid air and substitutes for drier air. The aftermath is a silent, non-disruptive and regular distribution of 3-5 mph breezes over large spaces with a cooling effect for occupants of up to nearly 6 degree celsius. During winter, HVLS fans evenly redistribute warm air trapped at the ceiling.
Their size provides an advantage to the user. They consume power at a fraction of the cost of multiple small ceiling fans. As mentioned before, HVLS fans with energy efficiency motors with different frequency drives and airfoil designs inspired by airplane wings to move humongous volumes of air while eliminating noise.
Before you buy HVLS fans, it is important to consider a few things beforehand.
● Type of Motor Unit
Both commercial and industrial HVLS fans have fan lines coupled with direct drive motor units. Some of these HVLS fans have both gearboxes and motors. The main difference between gearbox driven and direct drive motor units are sound, price and speed.
● Diameter of Fan
The size of the fan you buy has a lot to do with its functionality. It is important to record the size of the space in relation to the fan size. HVLS fans have a wide variety of sizes ranging from 6 to 24 feet in diameter.
● Air Movement and Speed
The speed at which a fan rotates has no relation to its performance and productivity. In fact, HVLS fans revolutions per minute are fairly lower than a high speed fan. This means it’s large diameter and long blades have an important role to play.
HVLS features a large diameter and slow rotational speed which allows the fans to move easily. The lower revolutions per minute HVLS fans allow them to move large volumes of air at slow speed.
● Types and Number of Blades
There are two factors to consider when it comes to blades.
1. Number of blades
HVLS fans have various numbers of blades as per the requirements of the manufacturer. It has been said by many engineers that 6 blades are optimal for energy accomodation and air movement. Some blades come with a specific width and shape.
2. Shape of blades
A popular misconception about HVLS fans is about the number of blades. Some HVLS fans have fewer airfoils that move less air or move the air less efficiently.
● Energy efficiency
HVLS fan efficiency is usually measured by the amount of air flow generated by the fan per watt energy used to power the fan.
In short, overall efficiency has a deep connection to moving more air using less energy.
Most of these HVLS fans are energy efficient by nature because their duty involves moving a large amount of air using lower speed. However, some HVLS fans are more energy friendly than others.
Another important factor is heating, ventilation and cooling costs. By using HSVL fans with HVAC systems, one can turn up the thermostat and due to the excellent air distribution of the HVLS fans while making the space more comfortable and saving the energy.
Why should you go for HVLS fans?
There are several benefits of using HSVL fans in your space:
Comfort and pocket friendly
When it’s hot outside, HSVL fans can be a godsend. With stirring up huge volumes of air instead of small sections, they make the environment cooler and comfortable for the users.
Some HVLS fans are so efficient at keeping the environment cooler, one can hardly think about using air conditioners even if it is a hot July afternoon we’re talking about.
Workplace safety
Not many of us are aware of sweating slab syndrome. It occurs when condensation builds up on the cement floors. As a result, the floor becomes slippery and this might jeopardize employees’ lives. HVLS fans support evaporation, they are excellent for moisture reduction on the ground reducing the risk of slipping on the floor.
Heat stress is another safety risk that facility managers should look after. During hot summers, workers need to keep themselves cool and comfortable. The ultimate solution to reduce heat stress concern is to increase air velocity. HVLS fans are your answer to this increased air velocity.
Pest Control Management
No one likes to have pests in his/her building. However, some pests are harder to control even especially those that can fly. One can take help of physical barriers like door screens and dock shelters can prevent pest threat to some degree but one needs to take additional measures to keep pests out. In order to avoid extra effort and struggle, HVLS fans assist to keep these pests out and make your facility better and safe.
We hope the above article helped you to know more about HVLS fans, what functions do they have, what features set them apart and what benefits you should expect from HVLS fans.
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