Altra-Air HVLS fans blanket a very large area with constantly moving air to create an expansive comfort zone.

As a result, the big ceiling fan can create an evaporative cooling effect of three to four degrees Celsius throughout the facility. Altra-AirFAQ

During the heating season, the Altra-Air HVLS fan technology can de-stratify uneven temperatures that can be in excess of fifteen degrees Celsius from ceiling to floor. This results in significant energy savings since the heating system cycles less frequently.Altra-Airimg

The Tubercle Advantage

Tubercle Technology™ blades outperform all conventional airfoils. They accomplish this by:

Offering stall angles as high as 22°.
• Always stalling gradually.
• Eliminating span-wise pumping; the primary cause of efficiency loss in all rotating systems.
• Eliminating tip stalling; the primary cause of blade noise and damaging vibration.
• Lowering noise by offering Tubercle Technology’s™ hyper-stability which also lowers vibrations which cause wear and tear on the blades and drive train.

Benefits of Altra-Air HVLS Fans

• Quiet, efficient operation, no annoying high speed circulating or exhaust fans.
• Virtually maintenance free (recommended inspection every 20,000 hours)
• Inexpensive to operate. Costs approximately 6 cents per hour for one fan at 0.75 kw.
• Greatly reduce the “recovery” time when overhead doors are open with a constant flow of air throughout the space.
• Provide a constant even temperature from floor to ceiling and wall to wall.
• Will minimize the need for expensive duct work in new construction for both heating and air conditioning systems.
• A comfortable workplace environment increases productivity and decreases absenteeism.

Technical Specifications

• Fans range from 2.4 to 7.3 m in diameter.
• Capable of moving nearly 188,000 l/s.
• Operates on 0.75 to 1.5 kw.
• Variable frequency drive provides soft start and full variable speed operation.
• Creates a non-disruptive airflow.
• The largest 7.3 m Altra-Air fan consumes less power than the average hairdryer.


Altra-Air fans come with a lifetime warranty on the blades and hub. The motor, gear reducer and VFD control panel come with a three year limited warranty.


Envira-North’s safety clips and blade safety links prevent a rotor from falling or a blade from coming off even in the unlikely event of a catastrophic failure of the hub or drive system. The collet-type friction drive bushing connecting the hub to the reducer shaft allows controlled slippage in the event of a seizure of the reducer mechanism, or a failure of the soft start feature in the control panel.


How to Calculate the Number of Fans Required for Your Building

1. Calculate the inside floor area of your building: fandiagram

Length x Width = m² 122 x 45 = 5,490 m²
Length x Width = ft² 400 x 148 = 59,200 ft²

2. Locate the structural columns or walls and measure the allowable distance. This will provide you with the max. fan diameter possible that can be installed in the space provide. See “A” and “B” for this example. We will say that both “A” and “B” are 6.7 m (22 ft) apart.

3. Obstructions such as floor equipment, walls or areas set out for storage must be calculated as these objects have direct impact on air circulation. Calculate the m² (ft²) areas of the equipment and figure the percentage of unobstructed space. For this example we will say the equipment in the space takes up 30% of the floor area leaving 70% unobstructed space.

4. In this example, we can install 6.1 m (20 ft) fans due to the 6.7 m (22 ft) column spacing. As per the catalogue specifications, the maximum effective diameter is 61.0 m (200 ft) per 6.1 m (20 ft) fan.

We then calculate the m² (ft²) area that each fan will cover:
Radius = Ø / 2
Radius = 61.0 / 2 (Radius = 200 / 2)
Radius = 30.5 m (Radius = 100 ft)
Area = πr²
Area = 3.14 x 30.5² (Area = 3.14 x 100²)
Area per fan is 2,921 m². (Area per fan is 31,400 ft².)

5. We then must calculate the number of fans required for the building size. We take the area per fan 2,921 m² (31,400 ft²) multiplied by the percentage of unobstructed area (70%).

2,921 m² x .7 = 2,045 (31,400 ft² x .7 = 21,980)

We then divide this number into the total area of the building.

5,490 m² / 2,045 = 2.70 (59,200 ft² / 21,980 = 2.70)

We require three 6.1 m (20 ft) WhalePower fans realizing that some overlap of coverage will result.