Selecting an HVLS Fan
HVLS fans are ideal for public spaces like airports, gymnasiums, auto dealerships, shopping malls, and arenas. The key to maximizing the benefit of the HVLS fan is choosing the best product design, the correct size and number of fans, and placing them properly in the space.
Direct Drive Motor: HVLS fans at the top of the industry have direct drive motors. Direct drive motors eliminate the gearbox and all its associated problems including noise, weight, and multiple moving parts.
On-Board Processer: HVLS fans with on-board processors eliminate the need for Variable Frequency Drives (VFD). VFDs are difficult to install because they create electromagnetic interference (EMI) and require precise spacing and unsightly cabling. EMI can disrupt electronic systems and harm computers, networks, and security systems so it is best to remove this complication in specifications.
Controller: Not all manufacturers offer the same capabilities and programming options from their controller so it is important to consider the occupants’ control needs when selecting an HVLS fan. If the client wants to easily adjust the speed of the fan, reverse the fan direction in the cooler months, or program run times, it is best to choose a controller with these options. Some controllers also allow the fans to be “daisy chained” allowing occupants to adjust multiple fans from one controller.
Ensuring the control interface is simple, intuitive, and accessible will encourage the occupants to actively engage in the climate control features of the design project. This will help reduce energy costs over time as the occupants alter the fan speed and not the HVAC system.
Size and Number
The number of fans needed in a particular space depends on many things including the
building’s total volume of air, shape, building material, occupied use, and intended HVLS solution. Because choosing the correct fan(s) for an application is complex, it is best to consult the HVLS manufacturer and request an airflow simulation. However, the table below provides a general fans to space comparison for your information. See the fans-to-space chart and diagram.
The illustration shows the proper spacing for two 8-foot HVLS fans. The fans are 60-feet apart. The smaller rectangle shows the minimum space required for an 8-foot HVLS fan (12 feet from the wall) and the large rectangle shows the maximum coverage radius.
Note: The diagram above represents the principles of spacing and acts as a simplification of how to properly space your HLVS fans. For detailed product and placement recommendations contact an HVLS manufacturer or distributor.
Positioning the fans to overcome ground obstructions is important to ensure full de- stratification of the space. If the obstruction is a single object, like a large piece of stationary equipment, the HVLS fan should be centered above the object whenever possible so that the air column can wash over the obstruction. If there are a series of obstacles, place the fans between the obstructions to allow the full column of air to fall directly to the floor. Because every building design is different, it is best to consult the HVLS manufacturer for installation placement recommendations.
Architects gain more control over air circulation when HVLS fans are included in the climate control strategy. Specifying HVLS fans help the building occupants enjoy better air quality and efficient temperature control.