What Are HVLS Fans?
HVLS fans stands for High Volume, Low Speed fans. The name means exactly what it says: they move large volumes of air at low speeds. How do they do that, you may ask?
1. By having more blades than standard industrial fans
2. By having cast aluminum blades engineered into a specific airfoil design
3. By being very big.
Yes, HVLS fans are those HUGE fans you might see at an airport, in a warehouse, or in a stadium. They range in size from 8′ to 24′ and have as many as ten blades, or as few as four. HVLS fans typically run at 50-100 rpm (revolutions per minute) or less. The standard size is 20′. Currently the three most popular companies making these fans are Big Ass Fans (yes, that’s actually their name), Macro-Air, and Rite Hite.
HVLS fans were invented for large industrial and agricultural settings, as an alternative to LVHS fans. LVHS fans, conversely Low Volume, High Speed fans, are the large caged fans you might typically see floorstanding or mounted to a wall in a factory, barn, or other large non-climate-controlled area. LVHS fans draw a significant amount of current, are noisy, and while they move a considerable amount of air, the air is channeled immediately in front of fan. So, they provide some cooling, but only in specific areas, and do very little by way of air mixing and heat destratification. A single 3′ LVHS fan may draw as much current as a 20′ HVLS fan, and yet it can take 6-10 LVHS fans to cover as much area as a single HVLS fan. Conventional ceiling fans, such as those typically discussed on this site, are known as LVLS (Low Velocity, Low Speed) fans for comparison. HVLS fans operate on the same principle as conventional ceiling fans, yet much larger.
20′ HVLS fans, on average, move 260,000 CFM (cubic feet per minute) of air, and draw 1,400 watts. Again on average, the cost-per-fan is around $4,000. They are recommended to be mounted on ceiling heights from 18′-40′, and of course can be mounted higher if necessary. HVLS fans typically require a three phase power supply, although the necessary speed control device can often double as a converter.
HVLS Fans Or Conventional Industrial Fans?
It goes without saying, and should be fairly obvious from the above paragraphs, that HVLS fans are light years better than LVHS fans. But how do they compare to using conventional industrial ceiling fans, aka LVLS fans? Ceiling-Fans-n-More has done some research. Here, using data we found available from the major manufactures, is a comparison:
(1) 20′ HVLS Fan (data averaged from the three most popular fans)
Air movement: 260,893 cubic feet per minute (CFM)
Area covered: 14,928 square feet
Recommended mounting height: 18′-40′
Power consumption: 1.442 kilowatts (1,442 watts)
Cost per fan: $4,438
(1) 56″ Envirofan Industrial Ceiling Fan (using specs from our Industrial Ceiling Fan Brand Review page, Editors’ Choice)
Air movement: 34,500 CFM
Area covered: 2,100 square feet
Recommended mounting height: 12′-40′
Power consumption: 0.0768 kilowatts (76.8 watts)
Cost per fan: $150
(8) 56″ Envirofan Industrial Ceiling Fans
Air Movement: 276,000 CFM
Area covered: 16,800 square feet
Recommended mounting height: 12′-40′
Power consumption: 0.6144 kilowatts (614.4 watts)
Cost per 8 fans: $1,200
Both types of fans were similar in terms of air velocity. HVLS fans deliver a breeze ranging from 3-5mph, the quality industrial ceiling fans produce 5-7mph. Many agricultural studies have been done comparing HVLS, LVHS, and LVHS fans. These studies have shown no (or minimal) difference in milk production, and other measurable agricultural results, between HVLS fans and LVLS industrial ceiling fans.
Based on spec, it would appear that the LVLS industrial ceiling fans are a more economical option than HVLS fans. There are, however, a variety of factors not included in specifications. For example:
- One large HVLS fan may be more effective in air mixing than several smaller fans covering the same area.
- Several smaller fans allow for individual control for comfort, or should one need be disabled or replaced.
- HVLS fans require minor regular maintenance to ensure safety.
- HVLS fans are large and may not fit into all installations. Also they are very striking in appearance, as opposed to industrial ceiling fans which blend.
- Industrial ceiling fans operate on 120vAC. HVLS fans require 220v single phase or a three phase power supply.
- Many HVLS fans are made in the USA.The biggest x-factor is HVLS fans have only been produced in very recent years. There is not yet data available on how they will last long term, and how they will stand up to demanding industrial and agricultural environments. It does appear the manufacturers are very involved in their products and stand behind them.The decision between HVLS ceiling fans and LVLS ceiling fans is subjective and will depend on the specific application, budget, and desired results. Contact the manufactures of the specific options with the details of your installation, and they will be able to provide you with very specific data.Editor’s note: There is much discussion about HVLS fans being significantly better than conventional ceiling fans. This is due to comparisons to poor quality industrial ceiling fans. If the choice is between poor quality industrial ceiling fans and HVLS fans, pick the HVLS fans every day! This is why we recommend the Envirofans for industrial ceiling fans.
HVLS Fan Comparisons
There are three major brands of HVLS fans, with many others emerging. Here we will provide specifications on the standard size model (20′) of each major brand, along with a brief description.
Big Ass Fans “Powerfoil”: These were the original HVLS fans, and they have the highest number of blades: 10. They also have the very amusing promotional material with the donkey.
Air movement: 223,572 CFM
Area covered: 14,400 square feet
Recommended mounting height: 18′-30′
Power consumption: 1288w
Cost per fan: $3,750
MacroAir “MaxAir”: These fans are very similar to the Big Ass fans, offering either 6 or 10 blade options. The MaxAir is their most powerful 20′ fan.
Air movement: 269,108 CFM
Area covered: 15,000 square feet
Recommended mounting height: 30′
Power consumption: 1590w
Cost per fan: $5,125
*Editors’ Choice – Rite-Hite Resolution Fans
Rite-Hite “Revolution Fans”: These fans have four blades, as opposed to 6 or 10, and appear more similar to a conventional ceiling fan. The blades have a unique design that allows them to lift slightly during operation to cover a greater area. They not only move the most air of any 20′ fan considered, they also have the greatest efficiency (CFM/watt) rating.
Air movement: 290,000 CFM
Area covered: 15,383 square feet
Recommended mounting height: 40′
Power consumption: 1449w
Cost per fan: unknown
*Editor’s Choice*