Multi-wing Engineering Guide

Interchangeable components Application versatility Choice of blade designs Five corrosion-resistant blade materials Tailored for the application

GENERAL ENGINEERING GUIDE.The Multi-Wing System.

P.O. Box 425 15030 Berkshire Industrial Parkway Burton, Ohio 44021 Toll Free: 800-311-8465 Phone: 440-834-9400 Fax: 440-834-0449 Web Site: www.mw-america.com E-Mail: [email protected]

MULTI-WING AMERICA, INC. A Crowley Company

More Information:

Multi-Wing Specifications

Performance Factors

Variable Factors

Application Assistance

Fan Selection Guide

Multi-Wing Home

ISO 9001-2000

Web Site: www.mw-america.com E-Mail: [email protected]

A Crowley Company

Fan Series H Z W 6Z Aluminum All-Plast

Blade twisted twisted twisted increasing twisted twistedProfile airfoil airfoil airfoil arc airfoil airfoil

Blades 2-14 3-16 3-10 3-16 2-16 2-8

Diameter 7"-29" 16"-49" 36"-78" 24"-49" 7"-60" 7"-30"

Angles fixed adjustable adjustable adjustable adjustable adjustablepitch pitch pitch pitch or fixed pitch or fixed pitch

25-45 20-50 25-50 20-35 20-50 20-45

Application industrial industrial industrial off industrial coolingHVAC HVAC HVAC highway HVAC ventilation

The Multi-Wing System Design Matrix

I-WING FANS.

H Series Fan Z Series Fan

All-Plast Series Fan6Z Series Fan Aluminum H & Z Series Fans

W Series Fan

meet your specific

eter from 7 to 78

h 2 to 16 blades and special

oatings for resistancelastic hubs

Performance FactorsVariable FactorsApplication AssistanceFan Selection GuideMulti-Wing HomeP.O. Box 425 15030 Berkshire Industrial Parkway Burton, Ohio 44021 Toll Free: 800-311-8465 Phone: 440-834-9400 Fax: 440-834-0449

MULTI-WING AMERICA, INC.

Fan Series 8D 8M 8W 8X

Blade twisted twisted broad twisted Profile paddle paddle blade paddle

Blades 2 or 4 4 3-5 3-5

Diameter 12"-26" 10"-20" 24"-48" 36"-68"

Angles fixed one piece adjustable adjustablepitch molded pitch pitch

25-40 30-40 15-45 20-45

Application HVAC HVAC HVAC HVAC

The Multi-Wing 8 Series System Design Matrix

PERFORMANCE ENGINEERED MULT

8D Series Fan

8M Series Fan

8W Series Fan

8X Series Fan

The Multi-Wing system uses standard,interchangeable components whichcan be custom modified to specificrequirements. Component standardi-zation means fast deliveries and nominimum order quantities or set-upcharges.

Multi-Wing Fans feature cast aluminum hubs and a variety of highperformance blade designs molded inengineered thermoplastics or die castaluminum. This gives them both lowweight and high strength, enablingthem to be used successfully in thousands of air-moving applicationsworldwide, ranging from engine cooling to ventilation.

Design Features Include: System of interchangeable

components+ Customized fans: number

of blades, pitch angles,diameters and blade materials

+ Off-the-shelf prices

Versatilitycan be used in all types of environments from HVACto engine cooling

+ Severe duty applications+ High vibration applications

Blade designs to meet your performance demands

+ High efficiency airfoil profile blades

+ Low speed broad paddle blades

+ Poor inlet resistant increasing arc profile blades

Blade materials to meet your application requirements

+ Glass reinforced polypropylene

+ Glass reinforced nylon+ Electro anti-static nylon+ Super Tuff nylon+ Die cast aluminum

Configured torequirements

+ Any diaminches

+ Fans wit+ Standard

mounting+ Special c

corrosion+ Thermop

available

ISO 9001-2000

FIG.1Deep Bell MouthEntire blade is covered byflat area of the venturi.

AIR FLOW

AIR FLOW

AIR FLOW

FIG.2Shallow Bell Mouth

If it is not possible to cover theentire blade with the flat portion ofthe venturi, then the leading edge

and as much of the fan as possibleshould be covered. Make sure theleading edge does not extend into

the bell portion of the venturi.

FIG.3Sharp Edge OrificeThe leading edge and two-thirdsof the fan should protrude on theair intake side of the opening.

S.Optimal Shroud Placement.

30

AIR FLOW

FIG.430 Inlet

The leading edge and two-thirdsof the fan should protrude on the

air intake side of the opening.

eb Site: www.mw-america.com E-Mail: [email protected]

A Crowley Company

Multi-Wing SpecificationsVariable FactorsApplication AssistanceFan Selection GuideMulti-Wing HomePERFORMANCE FACTOR

Influence of Tip Clearance onPerformance

Volume

Pre

ssur

e

0.5%1.0%2.0%3.0%

Comparative Performance forVarious Inlet Conditions

Volume

Pre

ssur

e Bell MouthFlat Plate

P.O. Box 425 15030 Berkshire Industrial Parkway Burton, Ohio 44021 Toll Free: 800-311-8465 Phone: 440-834-9400 Fax: 440-834-0449 W


Recommended Mountingfor Inlet Conditions.In general, the best operatingresults are obtained when theincoming air flow has a smoothentry to the fan. This is bestachieved by mounting the fan in abell mouth opening (see figs. 1 and2). The bell mouth opening reducesthe turbulence associated withmoving air, increasing fan efficien-cy and reducing noise.

The optimum bell radius is r/d =.12, where r is the radius of thebell and d is the fan diameter. Inapplications where this ratio maybe impractical, an r/d range of .07to .12 is recommended.

Many applications utilize a sharp-edge orifice, such as a hole in flat sheet metal. Whilethis is not the most efficientmethod, it can work satisfactorily if the fan is positioned within theorifice and a 2.5 percent or less tipclearance is maintained (see fig. 3).

Tip Clearance.In all applications the fan will perform at its highest efficiencywhen the tip clearance is 1 percent of the fan diameter. Inthose cases where this may not be practical, a range of 1 to 2.5 percent tip clearance isrecommended.

Fan performance significantlydecreases as tip clearances exceed 2.5 percent.

ISO 9001-2000

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A Crowley Company

Symbol Temperature Range Application Duty

ylene PPG -40 F to +185 F Standard Duty

PAG -50 F to +250 F Heavy Duty, Engine Driven

PAGST -50 F to +250 F Extreme Vibration

PAGAS -40 F to +250 F Hazardous Conditions

AL -60 F to +300 F Temperature Extremes

resistant and spark proof on impact.

for underground mining, oil and gas platforms, chemical processing plants, or any otential for explosion.

pplications, pressure die cast aluminum hubs and plastic hubs can be suppliedd stainless steel fasteners.

al Specifications.

on should be sing this formula,eme summer use motors to e winter conditions.uld be sized for thector in which the fan

ing.ents for Multi-Wingd in our wind re tested in MCA Standard 210hamber method the chamber. The

a bell mouth venturiarance of 1% of the

Multi-Wing SpecificationsPerformance FactorsApplication AssistanceFan Selection GuideMulti-Wing HomeP.O. Box 425 15030 Berkshire Industrial Parkway Burton, Ohio 44021 Toll Free: 800-311-8465 Phone: 440-834-9400 Fax: 440-834-0449 We


Blade Material

Glass Reinforced Polyprop

Glass Reinforced Nylon

Super Tuff Nylon

Electro Anti-Static Nylon

Die Cast Aluminum

All materials are corrosion

PAGAS blades are suitable application where there is p

For severe duty corrosive awith protective coatings an

VARIABLE FACTORS.Standard Correction Factor TableAltitude 0' 500' 1000' 1500' 2000' 2500' 3000' 3500' 4000' 4500' 5000'Pressure(Hg) 29.92 29.38 28.86 28.33 27.82 27.31 26.82 26.32 25.84 25.36 24.90

Temp. F-40 .79 .81 .82 .84 .85 .87 .88 .90 .92 .93 .95

0 .87 .88 .90 .92 .93 .95 .97 .99 1.00 1.02 1.0440 .94 .96 .98 1.00 1.01 1.03 1.05 1.07 1.09 1.11 1.1370 1.00 1.02 1.04 1.06 1.08 1.10 1.12 1.14 1.16 1.18 1.2080 1.02 1.04 1.06 1.08 1.10 1.12 1.14 1.16 1.18 1.20 1.22

100 1.06 1.08 1.10 1.12 1.14 1.16 1.18 1.20 1.22 1.25 1.27120 1.09 1.11 1.13 1.16 1.18 1.20 1.22 1.24 1.27 1.29 1.31140 1.13 1.15 1.17 1.20 1.22 1.24 1.26 1.29 1.31 1.34 1.36160 1.17 1.19 1.21 1.24 1.26 1.28 1.31 1.33 1.35 1.38 1.41180 1.21 1.23 1.25 1.28 1.30 1.32 1.35 1.37 1.40 1.42 1.45200 1.25 1.27 1.29 1.32 1.34 1.36 1.39 1.42 1.44 1.47 1.50250 1.34 1.36 1.39 1.41 1.44 1.47 1.49 1.52 1.55 1.58 1.61300 1.43 1.46 1.49 1.51 1.54 1.57 1.60 1.63 1.66 1.69 1.72350 1.53 1.56 1.58 1.61 1.64 1.67 1.70 1.74 1.77 1.80 1.84400 1.62 1.65 1.68 1.71 1.75 1.78 1.81 1.84 1.88 1.91 1.95

Blade Materi

A fan blade is a constant volumemachine, which means that a fan canmove a volume of air at sea level and the same volume at 5000 feet abovesea level. The difference is that the fancan move the air volume at a higherpressure level operating at sea levelthan it can at 5000 feet above sealevel. This is due to the density of theair at the operating conditions. In addition, the power required to operatethe fan will vary due to air density.

Therefore, when working with fancurves at standard operating conditions(70 F and sea level), it is important tocorrect your actual conditions back tostandard in order to be sure you aremaking the proper selection.

Altitude & TemperatureCalculationsExample: Required performance 10000cfm 0.50 inWG static pressure 5000feet elevation 200 degrees F. You are

working with curves where the performance is measured at standardoperating condition (70 F and sealevel)

Factor calculation 0.50 x 1.50 (factor from table) = 0.75 inWG Ps

The fan will have to produce 10000cfm at 0.75 inWG Ps at standard operating conditions in order to providethe required performance at the actualoperating conditions.

Power CalculationsTo determine the power required tooperate the fan at condition other thanstandard, divide the power required atstandard conditions, by the factor fortemperature and elevation at youractual conditions.

Example: 5.0 (Power from curves) /1.50 (factor from table) = 3.33 hprequired to operate the fan at 5000 ft

and 200O F. Cautiexercised when ufans sized for extrconditions may caoverload at extremThe fan motor shohighest density famay operate.

Air Flow TestAir flow measuremFans are conductetunnel. The fans aaccordance with AFigure 12, outlet cmultiple nozzles infans are tested inwith a total tip clefan diameter.

ISO 9001-2000

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A Crowley Company

ing at 1750 .92 HP will M powered

/1750)3

ulas

TP x D2 / 4

Force in Lbs.Pressureeter in Feet

P) + Velocity

n Square

P x 6356

Fan Tip Speed

Dia. (inches) x x RPM/720= Feet Per Second

Horsepower

HP = Watts/745.7

Full Load Torque

63030 x BHP/RPM = InchLbs. of Torque

Thousands of SuccessfulWorldwide Applications:

Air & Gas Compressors Air ConditionersIndustrial

& Commercial Air-Cooled Heat Exchangers Cooling Towers RefrigerationIndustrial &

Commercial Ventilation Air-Cooled Condensers Locomotive Cooling Railroad Air Conditioners RefrigerationTruck & Sea

Containers Generator Sets Engine Cooling

Details Are Yours forthe Asking.Because of all our attention tospecific details, its easy to see why Multi-Wing Fans aresuccessfully solving air-movingproblems in over 25 countriesaround the world.

Theyre known and respected ina wide variety of market applica-tions for high performance andtrouble-free service. Contact usfor further details on any of ourquality air-moving solutions.

CE.Multi-Wing SpecificationsPerformance FactorsVariable FactorsFan Selection GuideMulti-Wing HomeP.O. Box 425 15030 Berkshire Industrial Parkway Burton, Ohio 44021 Toll Free: 800-311-8465 Phone: 440-834-9400 Fax: 440-834-0449


Our technical specialists evaluateand adjust performance parame-ters like airflow, static pressure,diameter, fan speed, power inputand temperature and elevationfor each application. By doingthis, they are able to bring youthe best fan efficiency and performance range for yourrequirements.

Our specialists also check inletconditions, tip clearance, soundlevels and fan diameter and buildin safety factors for airflow andstatic pressure to handle lessthan ideal conditions.

All these steps are taken to giveyou the best solution for your air-moving requirements.

Technical Support from Experienced SalesEngineers.

Evaluation of the application provides you with the best solution for your air moving requirements

System design advice

Performance Optimizer Software

Auto CAD drawing system

Responsive CustomerService.

Short production lead time Emergency production Competitive pricing No minimum order quantity No production set-up charges Reliable JIT and KanBan

performance

Exceeding YourExpectations.

Committed to the quality standards of ISO 9001-2000

New CNC machining centers State of the art balancing

machines (ISO grade G6.3 is our standard)

Sound Advice.Sound information is developed inthe Multi-Wing laboratories forevery model of every fan wemake using standard testing andmeasuring procedures.

The information gathered is thenentered into the Multi-WingPerformance Optimizer softwarepackage that helps select thebest fan for a given application.

Some of the more common fannoise problems are:

Air turbulence High velocity air blowing over

fixed components which are not part of the fan

Fan wheel unbalance Resonance of fan or attached

components Rotating components rubbing

on stationary parts Operation in stall Belt slippage Air leakage which generates

a whistle-type noise Failing, misaligned or

contaminated bearings on the fan or on the motor

Coupling misalignment Motor noise, especially with

improper power supply Loose components

Helpful Fan Tips.

Fan LawsSpeed Change1. Volume varies directly with fan

speed.

CFM2 = CFM1 x (RPM2/RPM1)

2. Pressure varies with the squareof the fan speed.

Ps2 = Ps1 x (RPM2/RPM1)2

3. Horsepower varies with the cube of the fan speed.

HP2 = HP1 x (RPM2/RPM1)3

Examples:1. An impeller delivering a volume

of 6932 CFM at 1750 RPM will deliver 4516 CFM at 1140 RPM.

4516 = 6932 x (1140/1750)

2. An impeller capable of delivering .25 inches WG static pressure at 1750 RPM will develop .11 inches WG static pressure at 1140 RPM.

.11 = .25 x (1140/1750)2

3. An impeller operatRPM powered by 1operate at 1140 RPby .53 HP.

.53 = 1.92 x (1140

Useful Fan FormAxial Thrust

Fa = x 5.193 x Fa = Net Axial TP = Fan Total D = Fan Diam

Total Pressure

Static Pressure (SPressure (VP)

Velocity

V = CFM / Area (iFeet)

Velocity Pressure

VP = (V/4005)2

Total Efficiency

TE = CFM x TP/BH

APPLICATION ASSISTANISO 9001-2000


MULTI-WING AMERICA, INC. A Crowley Company

FAN SELECTION: THE KEY TO COOLING PERFORMANCE.Selecting the right fan for your cooling application can improve system efficiency and result in quieter performance. You can gain these benefits by considering a few designvariables that will help you optimizethe fan blade selection process.

How Much Air Do YouNeed?Airflow is the first design considera-tion. Whether the application is a cooling tower or an air-cooled condenser, airflow is required toremove heat from the process.

The amount of airflow required isdetermined by the rate of air velocity(measured in feet per minute) requiredthrough the condenser coils or coolingtower fill media in order to producethe desired latent heat transfer.

Static PressureStatic pressure in the simplest terms is a measure of the amount of resistance the fan must overcome todeliver X amount of air velocity acrossthe coils or through a fill media. Staticpressure (Ps) is measured in inches of water. The manufacturer through

testing has also determined theamount of static pressure for a coil or fill media.

Fan DiameterThe fan diameter is a variable, but isnormally determined by design constraints. Coil dimensions, availabilityof venturi orifices and package size limits all affect the size of the fan.However, the designer should always try to maximize the fan diameter for the application in order to provide maximum coil coverage and to reducesystem static pressure.

Operating Speed andAvailable PowerLike the fan diameter, speed andpower are determined by design constraints, or influenced by industrytradition. The fan application engineerwill need to know the designersdesired operating speed and available horsepower in order to meet the designer's expectations.

Ambient OperatingTemperature and ElevationAmbient operating temperature andelevation are two parameters that the

fan engineer will need to be aware ofin order to make the best recommen-dation for the cooling application.Typically, coil and fan test data areconverted to what is called standardair conditions (70 F @ sea level). Thisgives a common starting point for calculating performance variance from "standard condition."

For example, a fan has the following performance capabilities at "standard conditions." Table 1 provides a comparison of fan operation in standard vs. actual conditions.

Table 1. Effects ofOperating Conditions onFan PerformanceStandard Conditions: 70 @ sea level

10,000 cfm at .50 inWG Ps requiring 1.5 HP

Actual Conditions: 120 @ 5,000 ft.

10,000 cfm at .38 inWG Ps requiring 1.14 HP

As you can see, the fan's ability togenerate pressure is reduced by thelower air density caused by theincreased temperature and elevation.The example illustrates conditions thatan air-cooled condenser applicationmight be exposed to on a hot summerday in Denver, Colorado.

With the knowledge of temperatureand elevation, the fan applicationengineer can eliminate fans thatwould perform well at standard conditions but would become marginalselections at the actual operating conditions.

Actual OperatingEnvironmentWhile the operating environment will have little effect on the airflow performance, it has great effect on thelife of the fan. For example, coastalcooler applications are exposed to saltspray, and chemical process coolersare exposed to chemical corrosives.With knowledge of the operating environment, the fan engineer canmake the material or coating recommendation that will provide the best solution to the operating

environment. Table 2 shows availableblade materials and their suitableoperating environments.

Optimum Inlet Geometryand Fan Tip ClearanceThe fan inlet geometry and tip clearance also affect fan performance.Most fan blade manufacturers testtheir products to provide the maximumperformance and efficiency. This performance is achieved using aerodynamically superior bell mouthinlets and tight fan tip clearances.The fan application engineer will need to know the application inletconditions so that safety margins, ifrequired, can be added to the designparameters in order to compensate for the difference between actual andtest conditions (Figure 1).

Figure 1. Buildingsafety factors intodesign parametersavoids systemunderperformance.

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ISO 9001-2000

Multi-Wing SpecificationsPerformance FactorsVariable FactorsApplication AssistanceMulti-Wing Home

Figure 1. Testing HelpsPredict Performance

Minimizing Fan NoiseNoise is always a concern when itcomes to applications in which airmovement is required. With all the

concern about noise, the questionbecomes, how do you minimize it?

The best way to minimize fan noise isto produce the most aerodynamicallyefficient operating conditions as ispossible.

This is achieved by selecting a fanblade that will operate within its maximum operating efficiency range.An aerodynamically efficient airfoildesign like the Multi-Wing Z profile,creates less turbulence as energy is transferred to the air.

The fan blade diameter should also bethe largest possible for the physicallimits of the application. The maximum

possible diameter will reduce airvelocity across the fan blade.

To reduce tip-speed-generated noise,the fan should also operate at the lowest speed at which applicationparameters can be met.

The Fan Blade SelectionProcessArmed with the information provided by the customer, the fanapplication engineer, with the help of sophisticated computer software,reviews all possible combinations inorder to provide a selection whichproduces the maximum performancerange (Figure 2).

Figure 2. An Ideal Solution?When working with an applicationengineer, make sure you utilize aselection method based on providingan efficient working performancerange that builds in safety factors forboth airflow and static pressure whenconditions are less than ideal. Usingthe selection technique, system inefficiencies, both known andunknown, that will affect fan perform-ance are compensated for, reducingthe potential for an under-performing recommendation.

H Series

Z Series

W Series

8 Type

FAN SELECTION: Continued

Table 2. Suitable Blade Materials for a Variety of Applications.

Figure 1. Building safety factors intodesign parameters avoids systemunderperformance.

Figure 2. Although this may appear tobe the perfect solution, it will onlywork if all operating conditions in yourapplication are ideal.

Blade Material Symbol Temperature Range Application*

Fiberglass-Reinforced Polypropylene PPG -40 F to +185 F Corrosive: salt spray; light acidFiberglass-Reinforced Nylon PAG -50 F to +250 F Corrosive: acid; light salt

Super Tuff Nylon PAGST -50 F to +250 F Extreme VibrationFiberglass-Reinforced Nylon-Electro Anti-Static PAGAS -40 F to +250 F Explosive proof

Die Cast Aluminum AL -60 F to +300 F Wide temperature variations

* Always consult manufacturer to assure material performance.


MULTI-WING AMERICA, INC. A Crowley CompanyISO 9001-2000

Multi-Wing SpecificationsPerformance FactorsVariable FactorsApplication AssistanceMulti-Wing Home

Multi-wing Engineering Guide

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