Benefits of FANWALL TECHNOLOGY
An innovative air conditioning system
Small - Quiet - Energy Efficient - Reliable
Dramatically Shorter Footprint
Air handling equipment outfitted with HUNTAIR® FANWALL TECHNOLOGY® has a shorter footprint because the individual units are much shorter than units with a single, larger fan. The typical FANWALL® section is only 48 inches in length, compared to 120 to 150 inches for a standard single-fan element. The air-handling equipment’s length is dramatically reduced due to the shorter configuration of the fan section, typically by 30-70 percent. Rooftop air handling equipment and indoor mechanical rooms are both suitable for FANWALL installations. In both cases, the smaller size means more design freedom and reduced installation expense.
Lower Acoustic Signature
Quiet commercial air conditioners can be created. Using FANWALL TECHNOLOGY in your air handling equipment creates a quiet commercial air conditioner. Because the FANWALL approach uses multiple smaller motors and fans, and each is precision balanced, the acoustic signature is much lower than with a single larger motor and fan. Larger fan units often have significant "rumble" from vibration of the fan casing, as well as fan blade, belt drive, and motor noise. These types of unit noise are difficult to predict precisely in the design stage. FANWALL systems have much smaller individual casings, thus "rumble" is virtually eliminated. What fan and motor sound does occur is very predictable, and because it is a higher frequency, it can be more easily attenuated.
Larger single-fan units are commonly belt drive systems, a source of low-frequency vibration as well as whistling noises. FANWALL systems are entirely direct-drive, thus eliminating belt and pulley drive noise completely.
Reduces Expense for Attenuation
With FANWALL TECHNOLOGY, you can largely avoid costs for the typical air handler accoustic attenuation. Using a FANWALL TECHNOLOGY fan array provides acoustic performance features including a reduction of 16 to 18 decibels, sometimes more, in the first three octave bands over a typical single-fan system. With these levels of sound attenuation, the fan array becomes only a minor contributor to the building mechanical systems' acoustic signature.
In air handling equipment for which acoustic performance is a priority, the FANWALL units often include a "coplanar silencer," an engineered feature with a perforated inner wall backed by acoustically absorbent material. This air conditioning system is very effective in further dampening the high-frequency acoustic characteristic of the unit.
Elimination of Vibration
One key to FANWALL TECHNOLOGY is the careful attention given to balance in the design
and construction of the units. Each unit uses standardized precision parts, and
is individually spin-balanced at the factory to eliminate vibration. For this reason,
the assembled FANWALL fan array has far less internal vibration than a single large fan. This
feature also eliminates the need for costly concrete inertia bases and spring isolation
systems, thus helping reduce the cost of construction and simplifying retrofit projects.
Ideal for Retrofits
FANWALL units have a comparatively small size, and the modular characteristics of it
simplify air handler fan replacement, and allow the unit to be installed without
taking down walls or using large rigging equipment. In fact, the FANWALL elements
can be brought into the mechanical room in sections using a standard building elevator
and singe-walk door openings. The need to have a crane on site can be entirely
eliminated.
Because FANWALL designs use multiple fan units, or "fan arrays," the system can be matched exactly
to a building's air-handling needs, with the desired provision for future growth needs.
In retrofit situations where increased fan capacity is needed but the mechanical
room has a ceiling height restriction, the FANWALL array can be designed to spread the
fan units out horizontally.
VFDs Increase Flexibility
Another key advantage to FANWALL TECHNOLOGY is the creative use of variable speed
drives. VFDs provide flexibility in the volume of air delivered to the space, and
allow the air conditioning system to operate within its most efficient fan speed range. The system
allows the operating frequency of the fan motors to be adjusted from 60 Hz to 120
Hz.
Motor speeds from 60 Hz upward allow the motor to produce more airflow and keep
the fan blade tip speed in the most efficient zone: in the range between 70% and
90% of the peak static pressure capability. This approach is more efficient than
systems that operate fan motors with frequencies below 60 Hz for reduced fan load
output.
When Reliability is Critical
Any time an air handler fan fails, it causes problems. If the air-handling unit
has a single fan and motor, the loss of the air handler is complete. If the air
handler is serving a critical area, such a failure might result in financial loss
or even risks to health and safety. It's easy to see the advantage to the FANWALL
approach. If a single unit fails, the air handler capacity is typically reduced
only slightly, or, in the case where there is excess fan capacity, not at all.
Add to this advantage of redundant units the fact that direct-drive fans are inherently
less prone to failure—there are just fewer moving parts. A FANWALL TECHNOLOGY
system lets the facilities manager rest easy, knowing that the air will keep moving.
Easier to Maintain
Because the direct-drive units are mechanically simple, the need for regular maintenance
is dramatically reduced. Belt and pulley inspections, inventories, and replacements
become things of the past. On those rare occasions when maintenance or replacement is required, it is a far
simpler task. Because the individual units are relatively small, these jobs can
be handled on a non-emergency basis by the facility's own crew or those of the facility's regular HVAC
maintenance company.
Efficiency
Some have argued that single-fan air handlers are more efficient because of the
higher efficiency of larger motors. But there's more to it than that. With the use
of VFDs, the smaller motors on the FANWALL systems can be adjusted to operate in
the most efficient range.
Another efficiency advantage with FANWALL TECHNOLOGY is that with the array of fans across
the entire surface of the supply plenum, the airflow across the coil is even from
side to side, top to bottom. Some have compared it to a uniform piston of air moving
downstream from the fans.
A significant FANWALL efficiency advantage is the elimination of "junk in the air
trunk," (silencers, air blenders, motor drives, and guards), that add to the overall
system static pressure and consume more fan energy.