Fan Fundamentals Manual
Contents
1. 1 Roof deck to top of exhaust fan windband 40 min KSU Arrangement A 2 Roof deck to top of curb 18 min 3 Supply fan intake 10 min from all exhaust fans Optional Arrangement F SC For applications where the 10 horizontal distance cannot be met vertical separation between exhaust and _ J 12 supply must be at least 3 feet RENE EEEEER 11 General Commercial Ventilation G Direct Drive Roof Exhaust 80 4300 cfm Up to 75 wg GB Belt Drive Roof Exhaust 200 37 000 cfm Up to 2 5 wg CW Direct Drive Wall Exhaust 80 3 300 cfm Up to 625 wg CWB Belt Drive Wall Exhaust 300 12 500 cfm Up to 2 5 wg The above models are designed for exhausting relatively clean air at temperatures up to 130 F Motors are out of the airstream Direct drive sizes 60 95 are equipped with 3 speed motors for maximum airflow flexibility All direct drive units except 1725 rpm A speed can be used with a speed control SP an Ceiling Exhaust 50 1 600 cfm Up to 0 75 wg CSP Inline Cabinet Fan 100 3 800 cfm Up to 1 0 wg Models SP and CSP are designed for exhausting relatively clean air at temperatures up to 110 F Motors are in the airstream All models are direct drive and can be used with a speed control 12 A air R A F S RA D Ht D BSQ Belt Drive Inline Fan 300 26 600 cfm Up to 3 0 wg SO Di2. 0 35 852 1100 too Pe 3249 3094 2943 2786 2614 2428 2197 1899 15 3 0 48 14 7 0 50 14 1 0 52 13 8 0 53 13 5 0 53 13 0 0 53 12 5 0 52 12 0 0 50 eg Lee 2994 2833 2651 2427 2139 1700 GB 180 3 Ju 8 1 0 25 9 2 0 26 9 1 0 29 8 5 0 30 7 8 0 30 7 4 0 28 618 810 go ee 3150 2997 2832 2624 2375 2053 10 6 0 29 10 3 0 31 10 0 0 33 9 3 0 35 8 6 0 35 8 2 0 34 geg 4359 3500 3364 3219 3052 2858 2624 2347 1821 GB 180 5 i 12 7 0 40 12 4 0 42 12 1 0 44 11 3 0 46 10 5 0 48 10 2 0 48 9 8 0 47 9 2 0 43 700 940 gao laess 3655 3527 3388 3234 3052 2844 2601 2272 13 6 0 46 13 4 0 47 13 1 0 49 12 3 0 52 11 4 0 54 11 0 0 55 10 6 0 54 10 1 0 52 Sodol a845 3888 3768 3638 3504 3339 3164 2952 2712 2387 GB 180 7 an 15 2 0 55 14 7 0 57 13 7 0 58 13 3 0 62 13 0 0 64 12 4 0 66 11 9 0 66 11 6 0 65 11 1 0 63 764 1055 age Tea 4102 3989 3866 3741 3596 3432 3251 3050 2811 16 2 0 65 15 7 0 67 14 9 0 68 14 4 0 72 14 0 0 74 13 5 0 76 12 9 0 77 12 7 0 77 12 4 0 77 a ies 5739 4607 4507 4400 4290 4179 4045 3900 3753 3575 19 0 0 91 18 4 0 94 17 8 0 96 17 4 0 98 17 1 1 03 16 7 1 05 16 2 1 07 15 8 1 10 15 4 1 10 5191 5102 5010 4912 4814 4715 4599 4474 4343 ba 1 SIE EE sree 22 0 1 31 22 0 1 33 21 0 1 36 21 0 1 37 21 0 1 41 20 0 1 47 19 9 1 49 19 5 1 51
3. 19 2 1 54 alaan eri 5677 5595 5514 5424 5335 5245 5155 5049 4938 26 0 1 71 25 0 1 74 24 0 1 77 24 0 1 79 24 0 1 81 24 0 1 86 23 0 1 93 23 0 1 95 23 0 1 97 ne 3873 3591 3307 2973 2493 GB 200 5 To 10 3 0 39 9 6 0 40 9 2 0 41 8 6 0 41 7 8 0 40 512 770 zo Lang 4260 4013 3744 3477 3140 2643 12 1 0 52 11 0 0 53 10 7 0 55 10 2 0 55 9 8 0 55 9 3 0 52 18 Sound Levels In many cases the sound generated by a fan must be considered For the fan industry a common unit for expressing sound pressure level is the sone In practical terms the loudness of one sone is equivalent to the sound of a quiet refrigerator heard from five feet away in an acoustically average room Sones are a linear measurement of sound pressure levels For example a sound level of 10 sones is twice as loud as 5 sones Refer to the Suggested Limits for Room Loudness chart to determine the acceptable sone range for the application As a general guideline choose a fan that has a sone value within the range specified Note Rooms with a hard construction concrete block tile floors etc reflect sound For these rooms select fans on the lower end of the range Rooms with soft construction or those with carpeting and drapes etc absorb sound For these rooms fans near the higher end of the range may be selected Our example describes an exhaust fan for an office Referr
4. C D CVD TCD Domex DX XQ XR AT AW Cross Reference Chart PRN VEDK VEDB VEDC ILG cooLair Chelsea 3C 401 424 425 3C506 GB CDE CBX ACE B C B TCB UCB Domex DXB KB JB MB AB LB PN PNN VEBK VEBC 7H8 14 57 7C8 58 60 62 7C4 82 84 86 98 CUE ACRU D Fumex FX PDU VUDK 3C 367 766 770 AC 398 400 836 837 CUBE UCBE UCBH ACRU B VCR URB R B BTD Fumex FXB FMXB PNU PUB PU PUH VUBK VRBK VUBB URBA 7H 894 928 3C5 01 03 30549 CW SW GW ACW D CW ACW B CWB TWB Fumex WFX Domex WX WA WB Fumex WFXB Domex WCB WLB PDU W PW NBTD NBRTD UL 762 VWDK VWDB AC 398 400 836 837 3C367 4C 553 719 5C5 14 15 7H 894 923 Gemini GC Zephyr Z RA TD J EC L 4C 714 833 2D0 64 65 67 68 70 76 82 Gemini Inline GN DBX TDB Zephyr Z TDA ZC ZCC N A VDBA BCF TCF 4C756 3C505 SBE SBS SPFE SPFS SQI D SQN D CV D SQI D SQN B XLW XMW SWB SPB Centrex SX Centrex SX BC BBK BFL GDW HDW FDW VIDK VIDB AMDA VIBK VIBA LYDA LZDA LWDA LWBA LMBA TYPE T N A SBCL FHA IND 4C3 61 64 4C0 07 09 10 7CC 73 99 7CF 01 45 7CC 01 72 SBE SBS 3 SPNE SPNS SBCE SBCS HWB XLWH XMWH AWB BF DCK K LABA LCBA LBWA LRBA LNBA N A 7CC 73 99 7CF 01 45 7CC 01 72 7CK 38 52 RBE RBS RPE RPS RBU PBU PBU HSE HSS LSU
5. This drawing Bhowsa commercial kitchen with a typical kitchen ventilation Syste nsisting of a roof mounted SC CUBE upblast exhau t fanand a Model RSF supply fan yy LI Exhaust fan variations inc el CWB sidewall exhaust fan also shown when penetrating the roof is not practical The Model SWB utility blower is recommended when higher static pressure capability iswequired to pull exhaust through long duct runs typically stories or more Fan Sizing Exhaust When not specified by local codes the following guidelines may be used to determine the minimum kitchen hood exhaust cfm Some local codes require 100 cfm Ft of hood area for wall style hoods Supply 2 Recommended supply airflow is 90 of Type of Cooking Equipment cfm Ft of Hood exhaust cfm The remaining 10 of Light Duty Oven Range Kettle 50 supply air will be drawn from areas Medium Duty Fryer Griddle 75 adjacent to the kitchen which helps prevent undesirable kitchen odors from drifting into areas such as the dining Static pressure typically ranges from 625 to 1 0 for 1 story buildings room Heavy Duty Charbroiler Electric Broiler 100 10 0 Min NFPA Considerations The National Fire Protection Association specifies minimum distance criteria for restaurant exhaust and supply fans as shown below Arrangement A
6. 5 1400 RPM o o5 2 0 K He Q 1 5 1 0 as Operating 700 RPM at 1400 RPM 0 5 Operating oin 0 0 at 700 RPM 0 5 10 15 20 25 30 35 40 45 CFM x 100 For our example o uy 1400 rpm _ pn Ps 0 25 x 700 rom 1 0 This verifies the operating point on the 1400 rpm curve 2000 cfm at 1 0 Ps With this example it should be clear how cfm rpm and Ps tie together in a steady state system 23 Fan Laws In a steady state system as the fan rom changes cfm Ps and BHp horsepower also change The equations below known better as fan laws show the relationship between these performance parameters rpm CfMyew sie X Cie Old 2 rom Psne p Set x PSoid rPMoid rPMyew i Bhpnew _ x Bh Pn LU x Pon The first two equations have already been covered in the fan and system dynamics section Refer to the examples in those sections on how to apply these equations The third equation relates horsepower to rom The change in horsepower can be determined when the rpm is increased by 25 This is shown below BhPnew 1 25 x Bhpow 1 95 x Bhpouw NOTE a 25 increase in rpm results in a 95 increase in horsepower Considering this initial fan selections should be sized with motor horsepowers greater than necessary if any increase in fan rpm is likely in the future 24 GREENHECK P O BOX 410 SCHOFIELD WISCONSIN 54476 0410 PH 715 359 6171 www greenheck com Fan Fund R
7. AVB VB HF HZ EC EC S UBG UB LTBA LGBA 7CF 46 99 7CH 03 17 7CH 18 89 7C8 63 87 97 7C9 03 08 RSF ASP CFS Muffan MU AFS PLS 7C1 58 61 64 69 76 81 7C2 06 08 13 18 20 23 25 55 7C3 48 50 54 56 58 61 65 68 7C3 70 78 92 95 FHI FHR GRV 1 RVA RVG TEV TIV N A GRS DR GRV ARVE N A SWB Competitor Model Number Deciphering Hints Cook Direct Drive Dynamo D QX GWB Belt Drive JVS BCL 7H1 23 95 Belt Drive PNN 163 G 4 2 hp Wheel Size 16 3 Acme Direct Drive 120 W 10 D 150V 6B PW 135A8 Direct Drive Belt Drive Sig J T860 rpm rpm x 100 3 4 hp 1 20 hp Model ACW Model VCR Wheel Size 13 5 Wheel Size Wheel Size 15 Model PW Letter Designations C ACE G GB R ACRU CUBE W ACW CW CWB V VCR CUBE Horsepower Designations 2 1 6hp 6 3 4 10 3 3 1 4 7 1 11 5 4 1 3 8 11 2 12 71 2 5 1 2 9 2 Direct Drive rpm Designation Model PNN Horsepower Designation 8 860 rpm A 1 20hp F 1 3 L 2 6 1160 rpm B 1 12 G 1 2 M 3 4 1725 rpm C 1 8 H 3 4 N 5 D 1 6 J 1 P 71 2 E 1 4 K 11 2 R 10 FAN SELECTION BASED ON FAN APPLICATION Basic Overview Ventilating a building simply replaces stale or foul air with clean fresh air Although the ventilation process is required for many different applications the airflow fundamentals never change Undesired air
8. CFM x 100 Note Physically changing the system will alter the system resistance For example closing a damper from 100 open to only 50 open will add resistance and increase the steepness of the system resistance curve The same effect occurs as filters become dirty The figure above illustrates this point Curve A defines a system that requires 0 5 Ps to move 1000 cfm Curve B requires 0 75 Ps to move the same amount of air This is typical of how a system reacts to increased resistance In this section there are three key points to emphasize 1 As airflow through a system changes so does the static pressure 2 For a steady state system operating points must lie on the curve defining that system s cfm Ps characteristics 3 As the system s resistive elements change the steepness of the system resistance curve changes Combining Fan and System Dynamics The previous two sections introduced fan curves and system resistance curves This section will show how these relate to each other to provide an understanding of the way the fan system operates as a complete entity 22 Remember that a fan curve is the series of points at which the fan can operate at a constant rpm Likewise a system resistance curve is the series of points at which the system can operate The operating point cfm Ps for the fan system combination is where these these two curves intersect The operating point of the fan and the sy
9. Feet Per Minute A measure of airflow Ps Static Pressure Resistance to airflow measured in inches of water gauge sone A measure of loudness One sone can be approximated as the loudness of a quiet refrigerator at a distance of 5 feet Sones follow a linear scale that is 10 sones are twice as loud as 5 sones Bhp Brake Horsepower A measure of power consumption Used to determine the proper motor horsepower and wiring hp Horsepower Used to indicate a fan s motor size rpm Revolutions Per Minute Measure of fan speed TS Tip Speed The speed of the tip of a fan wheel or prop measured in feet per minute AMCA Air Movement and Control Association A nationally recognized association which establishes standards for fan testing and performance ratings AMCA also licenses air volume and sound certified ratings Model Designation For Greenheck belt drive models the model designation tells the model type size and the motor hp EXAMPLE GB 90 4 Model is GB hp is 1 4 Nominal Wheel Dia 9 For direct drive units the model designation tells the model type the size and the motor fan rpm EXAMPLE G 120 B Model bes 8 rpm is 1140 Nominal Wheel Dia 12 The table below lists model designation suffixes for motor horsepower and fan rpm Lg Belt Drive _ _ ee e ee p 3 tT B 1140 BL 2 C 860 DT 1550 10 i E J 1050 EE EES WR E ee Oooo S Reading Performance Charts T
10. application Our static pressure of 0 5 was only an estimate It may actually turn out to be 625 If this is the case we will need a 1 2 hp motor because our fan will have to run at almost 900 rpm refer to performance box 2624 cfm at 0 625 Ps Therefore choosing a 1 2 hp motor in this case is exercising good judgement The complete model designation for this application is GB 180 5 Note The GB 180 5 has an rpm range of 700 940 refer to model column in catalog This means that if the static pressure is less than estimated say 0 25 Ps the fan can be slowed down to accommodate this condition GREENHECK 19 GREENHECK Installation To ensure proper fan performance as cataloged selected dampers etc can cause reduced caution must be exercised in fan placement and performance excessive noise and increased connection to the ventilation system Obstructions mechanical stressing For the fan to perform as transitions poorly designed elbows improperly published the system must provide uniform and stable airflow into the fan Uniform Flow Improperly sized or Elbow too close obstructed damper to fan inlet Wheel Rotation A common problem is wheel rotation in the wrong When connecting a 3 phase motor there is a 50 direction For centrifugal fans incorrect wheel rotation chance that the fan will run backwards Changing any will provide some airflow However the airflow willbe two supply power conne
11. be accurate For example the GB 200 selection see table below of 2493 cfm at 0 50 Ps is the far right selection at 700 rpm The next box to the right 0 625 Ps is empty because the performance at that point is unstable This means that 2494 cfm at 0 50 is marginally stable For more information on fan stability contact Greenheck STATIC PRESSURE CAPACITY SE hp rem TS 0 000 0 125 0 250 0 375 0 500 0 625 0 750 0 875 1 000 rpm P Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp GB 140 5 Lull 4360 5207 2522 2433 2346 2258 2166 2062 1942 1792 1602 1125 1360 14 6 0 48 14 3 0 50 13 9 0 51 13 5 0 52 13 1 0 52 12 7 0 52 12 2 0 53 11 6 0 52 11 0 0 51 2866 2787 2709 2634 2556 2475 2384 2286 2176 S 3 4 eee 4 1545 5915 77 670 71 18 0 0 721 17 4 0 74 17 1 0 75 168 0 76 15 9 0 77 14 9 0 77 14 8 0 771147 0 78 2318 2104 1875 1587 GB 160 4 1 785 3416 39 o18 8 5 019 83 019 7 8 0 19 634 865 oe Tasten 2555 2359 2162 1932 1624 10 6 0 24 10 1 0 25 9 7 0 26 9 4 0 26 8 8 0 25 See gene 2909 2737 2567 2382 2176 1914 1550 GB 160 5 45 13 4 0 35 12 7 0 36 12 3 0 37 11 9 0 38 11 5 0 38 10 9 0 37 10 2
12. out fresh air in The key variables that do change depending on applications are the fan model and the air volume flow rate cfm Other considerations include the resistance to airflow static pressure or Ps and sound produced by the fan Sones Occasionally a customer will require a fan to perform a particular function yet does not know which model to use or even what cfm is necessary In this case some fan specification work must be done Fan Model Fans all perform the basic function of moving air from one space to another But the great diversity of fan applications creates the need for manufacturers to develop many different models Each model has benefits for certain applications providing the most economical means of performing the air movement function The trick for most users is sorting through all of the models available to find one that is suitable for their needs Here are some guidelines Direct Drive vs Belt Drive Direct drive fans are economical for low volume 2000 cfm or less and low static pressure 0 50 or less They require little maintenance and most direct drive motors can be used with a speed control to adjust the cfm Belt drive fans are better suited for air volumes above 2000 cfm or static pressures above 0 50 Adjustable pulleys allow fan speed and cfm to be adjusted by about 25 High temperature fans above 120 F are almost always belt driven Fan specification is usually not a precise
13. science and can be done confidently when the fan application is understood Based on the application four parameters need to be determined They are 1 Fan Model 2 cfm 3 Static Pressure Ps 4 Loudness limit Sones The information that follows will help walk you through this type of problem and enable you to select the right fan for the job Propeller vs Centrifugal Wheel Propeller fans provide an economical method to move large air volumes 5 000 cfm at low static pressures 0 50 or less Motors are typically mounted in the airstream which limits applications to relatively clean air at maximum temperatures of 110 F Centrifugal fans are more efficient at higher static pressures and are quieter than propeller fans Many centrifugal fan models are designed with motors mounted out of the airstream to ventilate contaminated and high temperature air Fan Location Fan models are designed to be mounted in three common locations on a roof in a wall or in a duct Whatever the location the basic fan components do not change Only the fan housing changes to make installation as easy as possible Determining the best location for a fan depends on the airflow pattern desired and the physical characteristics of the building By surveying the building structure and visualizing how the air should flow the place to locate the fan usually becomes evident Examples of fans installed in common applications are illustrat
14. 25 11 6 0 25 1070 3116 GB 100 4 2A 474 1020 1400 see 856 739 7 2 014 68 0 14 735 385 1260 3669 GB 100 4 3A 5 9 0 115 4 4 0 083 1260 1635 agane a 1161 1094 1019 928 792 9 8 0 25 9 3 0 25 8 9 0 25 8 4 0 25 7 8 0 24 Geaon val anon kee 1320 1270 1208 1141 1064 12 2 0 33 11 3 0 33 10 8 0 33 10 6 0 33 10 1 0 33 One advantage of choosing the GB 100 4 3A over the GB 100 4 2A is that it is capable of running at higher rpm s which enables the fan to move more air if necessary Motor pulleys are adjusted by loosening the set screw and turning the top half of the pulley see illustrations at right This causes the pulley diameter to change which results in changing the fan rpm Opening the pulley decreases fan rpm Closing the pulley increases fan rpm Direct Drive Selection Selection of direct drive fans those with the motor shaft connected to the fan wheel or propeller is nearly the same as belt drive selection However there are two differences worth noting Where belt drive fan speed can be altered by adjusting the motor pulley direct drive fans since they have no pulleys must use a different method 1 To adjust a direct drive fan s speed also motor speed or to provide a means of meeting an exact performance requirement a speed control can be furnished except on 1725 rpm motors Speed controls va
15. A 8 uilt into duct system fhe Supplying Fresh Air ONT Weatherhood gt Duct System Outside Air Office Space KW Model BSQ Work Work Stale air exiting Belt Drive Inline Fan Station Sanon ie 300 26 600 cfm Temperatures up to 180 F Up to 3 5 wg Typical Applications Models SWB and BSQ are general all purpose fans that are capable of moving high air volumes against high static pressures up to 4 0 wg High static pressures are generated by long or complex duct systems especially when capture hoods are present Both models can be used for either exhaust or supply Model SWB is designed to be mounted indoors or outdoors while model BSQ can be used indoors only 15 Determining cfm After the model is known the cfm must be determined Consult local code requirements or the table below for suggested air changes for proper ventilation The ranges specified will adequately ventilate the corresponding areas in most cases However extreme conditions may require Minutes per Change outside of the specified range To determine the actual number needed within a range consider the geographic location and average duty level of the area For hot climates and heavier than normal area usage select a lower number in the range to change the air more quickly For moderate climates with lighter usages select a higher number in the range To determine the cfm required to adequately ventilate an area divide the room volume by the appro
16. A which also has a 1 4 hp motor Both the GB 90 4 and the GB 100 4 2A will perform the air movement task equally as well However the sound generated by the fan may have to be considered Compare the sone values 7 9 sones for the GB 100 and 11 1 for the GB 90 The GB 100 is about 30 quieter Where a low sound fan is required the GB 100 would be a better selection If loudness is not a factor the GB 90 would be a better selection because it is less expensive Another possibility for this particular selection is a GB 100 4 3A Even though there is no performance box showing close to 1000 cfm there are two performance boxes that bracket 1000 cfm At 921 cfm the fan will be running at 1260 rpm At 1269 cfm the fan will be running at 1635 rpm Therefore there is an rpm for this model that will correspond to 1000 cfm obviously somewhere within the 1260 1635 rpm range As with all Greenheck belt drive fans intermediate cfm values are easily achieved by adjusting the motor pulley see illustration on next page Table 2 Ee STATIC PRESSURE CAPACITY nanan P mm TS 0 500 0 625 0 750 0 875 1 000 g i i Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp 1360 3983 ia Bee 8 8 0 13 8 5 0 13 GB 90 4 174 1510 4422 275 200 120 e07 1290 1710 10 4 0 17 10 0 0 17 9 8 0 17 95 0 17 ong Lee 1061 999 934 866 785 12 7 0 24 12 4 0 25 1241 0 25 11 8 0
17. also a 0 08 pressure drop for each resistive element or fitting For this example there are 5 fittings 17 Preliminary Selections At this point we know the model cfm and Ps With this information we can refer to the GB performance charts to determine the sizes available to move 2400 cfm against 0 50 Ps In our case all of the criteria can be met by more than one size of a particular model When this occurs choose the size that provides the greatest airflow range about the desired cfm For example many direct drive fans have three speeds If possible choose a size that uses the middle rpm This will allow some final system adjustment if the actual cfm the job requires is somewhat higher or lower once the fan is installed Belt driven fans have adjustable motor pulleys which allow the fan speed to be varied With belt drive units avoid selecting near the maximum rpm of a size to allow for final adjustments if necessary There are four GB sizes to choose from in the QD catalog These sizes along with their performance data are in the table below Model and Performance Box Data en Size cfm Sones Bhp GB 140 2556 168 76 1545 GB 160 2614 i GB 180 2375 86 2493 7 8 40 700 Stability Considerations Whenever there is more than one size to choose from it is not recommended to select from the performance box in the far right column for any given rpm unless the Ps is known to
18. ctions will reverse the far below the cataloged value Rotation should be direction of rotation checked while the fan is coasting to a stop Proper rotation for the most common wheels are shown below Ro ef Backward Airfoil Forward Inclined Curved 20 FAN PERFORMANCE The first two sections of this guide contain information needed to select the right fan for the particular application The information in this section is useful once the fan has been selected and installed on the job Fan Dynamics A fan is simply an air pump The rate at which a fan can pump air depends on the pressure the fan must overcome This principle also relates to water pumps A water pump is able to deliver more water through a 2 diameter hose than a 1 diameter hose because the 1 hose creates more resistance to flow For a fan every flow rate cfm Cubic Feet per Minute corresponds to a specific resistance to flow Ps static pressure The series of cfm Ps points for a fan ata constant rpm is called a fan curve A fan curve at 700 rpm is shown below Fan Curve 0 7 0 6 700 RPM 0 5 0 4 Static Pressure 0 3 0 2 0 1 0 2 4 6 12 14 16 18 8 10 CFM x 100 The fan curves and system resistance curves below will help to solve fan performance problems that may be encountered in a variety of applications At 0 25 Ps this fan will deliver 1000 cfm If the pres
19. ed on the following 6 pages Even if you come across an application that is not shown in this manual the concepts remain the same Commercial Kitchen Ventilation Recommended Exhaust Fans Model CUBE Model CWB Model SWB Belt Drive Upblast Roof Exhaust Belt Drive Sidewall Exhaust Belt Drive Utility Blower 600 30 000 cfm 300 12 500 cfm 1 000 30 000 cfm Up to 5 0 wg Up to 2 5 wg Up to 4 0 wg The above models are designed for exhausting dirty or grease laden air up and away from the roof line or away from the wall in commercial restaurant applications All three models are UL 762 listed for restaurant applications and for operation with air temperatures up to 300 F Recommended Supply Fans Model KSU Tempered Roof Supply 1 000 7 400 cfm a Up to 2 0 wg Model BSQ Belt Drive Inline Fan 300 26 600 cfm Up to 3 5 w Model RSF S Filtered Roof Supply 900 14 300 cfm Up to 1 5 wg The above models are designed to provide efficient economical make up air to replenish the air exhausted through the kitchen hood Provisions for make up air must be considered for proper kitchen ventilation 10 Commercial Kitchen Ventilation Upblast Exhaust Fan _ Model CUBE gt Model RSF ES Supply Fan Vented Curb Model GPFV gt oe kK Sova as Model CWB Model GHW Exhaust Hood Sidewall Exhaust i i
20. ev February 1999
21. haust fan If there were no provisions for make up air in this room a supply fan would also have to be sized The supply cfm should equal the exhaust cfm Supply fan location should be as far as possible from the exhaust fan Louvers to supply Makeup air Determining Static Pressure The pressures generated by fans in ductwork are very small Yet accurately estimating the static pressure is critical to Exhaust Fan proper fan selection Fan static pressure is measured in inches of water gauge L One pound per square inch is equivalent to 27 7 of water gauge Static pressures in fan systems are typically less than 2 of water gauge or 0 072 Psi The drawing to the right illustrates how static pressures are measured in ductwork with a manometer A pressure differential between the duct and the atmosphere Anw will cause the water level in the manometer legs to rest at S different levels This difference is the static pressure Ge measured in inches of water gauge Atmospheric Pressure Manometer In the case of the exhaust fan at right the air is being drawn upward through the ductwork because the fan is producing a low pressure region at the top of the duct This is the same principle that enables beverages to be sipped through a straw The amount of static pressure that the fan must overcome depends on the air velocity in the ductwork the number of duct turns and other resistive elements and the duct length For proper
22. he most important part of selecting a fan is the ability to read the performance charts Most of the performance charts in the catalog are similar and are read in the same manner Models RSF and BCF are Belt Drive Assume that a job requires a belt drive roof exhauster to move 1000 cfm against 0 25 Ps Refer to the performance model at the bottom of this page Start at the top of the chart with the 0 25 Ps column All numbers in this column correspond to 25 Ps Now follow the column downward until a value is found that slightly exceeds 1000 cfm In this case 1012 cfm is the first box that meets the requirements Note Notice that each performance box is divided into 3 smaller boxes The numbers refer to cfm Sones and Bhp Example At this performance point the sone value is 11 1 and the fan Bhp required is 0 16 Now by following the row to the left we can determine fan rom and fan model In this case the fan rpm is 1510 and the model is GB 90 4 which has a 1 4 hp motor Notice that the GB 90 4 is not the only model to choose from If we follow the 0 250 Ps column down further we find a performance point at 1010 cfm At exceptions to this rule The selection procedure for these models is handled separately Direct drive and belt drive fans are also addressed separately Selection this point the sone value is 7 9 and the Bhp is 0 14 Following across to the left we find the rpm to be 1355 The model is GB 100 4 2
23. ing to the Suggested limits for Room Loudness chart offices should have a loudness range from 4 to 12 sones Of our remaining three selections only the GB 180 has a sone value of less than 12 Therefore the GB 180 is the best selection for this application Suggested Limits for Room Loudness Sones DBA 1 3 4 32 48 Private homes rural and suburban 1 7 5 36 51 Conference rooms 2 6 38 54 Hotel rooms libraries movie theatres executive offices 2 5 8 41 58 Schools and classrooms hospital wards and operating rooms 3 9 44 60 Court rooms museums apartments private homes urban 4 12 48 64 Restaurants lobbies general open offices banks 5 15 51 67 Corridors and halls cocktail lounges washrooms and toilets 7 21 56 72 Hotel kitchens and laundries supermarkets 12 36 64 80 Light machinery assembly lines 15 50 67 84 Machine shops 25 60 74 87 Heavy machinery From AMCA Publication 302 Application of Sone Ratings for Non Ducted Air Moving Devices with Room Sone dBA correlations Motor Horsepower The motor horsepower for direct drive fans is always sized by Greenheck and does not require further consideration For belt drive models the catalog identifies which horsepower is recommended However there are times when it is wise to bump the horsepower one size For example the hp recommended for the GB 180 at 810 rpm is 1 3 hp Although a 1 3 hp motor is recommended it is not necessarily a good motor selection for this
24. lects the steepness of the parabola This equation literally states that Ps varies as the square of the cfm For example whenever the cfm doubles the Ps will increase 4 times The figures on the next page graphically illustrate this concept GREENHECK S 21 System Resistance Curve 1 4 1 2 1 0 0 8 Static Pressure 0 6 0 4 0 2 0 0 0 5 10 15 35 40 45 20 25 CFM x 100 Sample problem If a system is designed to move 1000 cfm ata resistance of 0 25 Ps what static pressure would the fan have to overcome to produce 2000 cfm of airflow Solution Since static pressure varies as the square of cfm we can solve for the new Ps Ps2 with the following equation _ cfm2 2 2000cfim _ pu Pse Ps x Se 0 25 x Tooo cfm 1 0 Referring to the figure above this results in sliding up the system resistance curve from Point A to Point B For this system it is impossible to move 2000 cfm at only 0 25 Ps For any given system every cfm requires a unique Ps This series of cfm Ps points forms a system resistance curve such as the one above Once the system resistance curve is defined changing the fan rpm will change the cfm and Ps simultaneously which results in sliding along the system resistance curve Varying System Resistance Curve 1 4 Static Pressure 0 2 4 6 8 10 12 14 16 18
25. ly designed systems with sufficient make up air the guide lines in the table below can be used for estimating static pressure STATIC PRESSURE GUIDELINES Aiton to Ductwork exhaust fan Non Ducted 0 05 to 0 20 E Ducted 0 2 to 0 40 per 100 feet of duct assuming duct air velocity falls within 1000 1800 Fittings 0 08 per fitting elbow register grill damper etc Kitchen Hood Exh 0 625 to 1 50 DE Important Static pressure requirements are significantly affected by the amount of make up air supplied to an area Insufficient make up air will increase static pressure and reduce the amount of air that will be exhausted Remember for each cubic foot of air Airflow out of exhausted one cubic foot of air must be supplied restaurant Grill To calculate the system losses one must know the one grill two duct turns one damper and louvers in ductwork system configuration see Ductwork figure the wall of the office The total pressure drop for fittings is This duct is sized for air velocities of 1400 feet per minute Referring to the static pressure chart that will 5 x 0 08 0 4 result in about 0 3 per 100 feet Since we have 10 feet Therefore the total pressure drop is of total ductwork our pressure drop due to the duct is p H 0 03 0 40 0 43 For convenience in using selection charts round this value up to the nearest 1 8 which would be 0 50 Ps 3 n 100 oni 10ft 03 There is
26. priate Minutes per Change value Suggested Air Changes for Proper Ventilation Room Volume t Area Dance Hall Dining Room Dry Cleaner Engine Room Factory Foundry Garage Min Chg 3 10 2 4 3 10 2 3 2 4 12 18 1 3 3 7 3 5 4 10 4 6 3 7 Area Assembly Hall Attic Auditorium Bakery Bar Barn Boiler Room Bowling Alley Cafeteria Church Classroom Club Room Gymnasium Kitchen Laboratory Laundry Sample problem A building requires an exhaust fan to ventilate a general office see diagram below which measures 30 x 40 x 8 The office is often crowded Solution The total room volume is 30 x 40 x 8 9600 cubic feet From the chart the range for general offices is 2 8 minutes per change Since the office has heavier than normal usage 4 minutes per change is recommended Therefore the required exhaust is 9600 ft 2400 cfm 4 min Exhaust fan to be sized 16 Generator Room Room Volume L x W x H of room Min Chg 3 6 3 8 2 8 Area Machine Shop Mill Office Packing House Projection Room Recreation Room Residence Restaurant Rest Room Store Transfer Room Warehouse Min Chg 3 7 4 8 2 5 1 3 2 7 1 5 2 10 2 5 3 8 1 5 2 5 2 4 Since the air to be exhausted is relatively clean this is an ideal application for a model GB fan Note In this example make up air was provided through a set of louvers at the wall farthest from the ex
27. r J replacing air being exhausted Model SB Belt Drive Propeller Sidewall 2 000 85 000 cfm Model RBU TF roof upblast fan Loading ke dock Doors RBU Outside air entering through door Model RBU RBUMO kii Belt Drive Propeller Upblast 4 000 62 000 cfm EE fan Outside air drawn in by an Q Loading ke dock Doors Internal air exiting through door opening Model RB RBS Supply RBE Exhaust RBF Filtered Belt Drive Propeller Roof 2 000 82 000 cfm Typical Applications Propeller fans are ideal for ventilating high air volumes at low static pressures 0 50 or less Industrial applications often include factories and warehouses A variety of fan models offer flexibility for roof or wall mount as well as exhaust or supply However because the motors are mounted in the airstream these models are not recommended for temperatures above 110 F 14 High Static Pressure Ventilation Model SWB Exhausting Foul Air utility blower Discharge Air J Duct System gt Intake Louvers X Outside air replacing air eing Model SWB Work Work Work exhausted Belt Drive Utility Blower Contaminated Air Station Station Station 1 000 30 000 cfm Temperatures up to 300 F Up to 4 0 wg Model BSQ S SE
28. rect Drive Inline Fan 200 5 000 cfm Up to 1 0 wg Models SQ and BSQ are versatile fans that can be used for exhaust or supply and can be mounted in any position Two removable side panels provide access for service Typical Commercial Ventilation Installations Greenheck Model G or GB Exhaust through wall or roof SCH get Accessory Roof Vent Roof Exhauster Greenheck Accessory AES Hooded Wall KH i Model SP Ceiling Exhaust Ka Rest Room This drawing demonstrates how to ventilate Typical restroom exhaust system more than one area with a single fan Multi story building prevents roof penetration Model GRS Domed Gravity Hood Ceiling Floor x Se Model CW or CWB M l P B J X odol sh 2a or BSQ Ser T Sidewall Exhaust Fan Inline Cabinet Fan E Insulated Ductwork Engine Room Laundry Room etc Sound Critical Room Office Conference Room etc Hall For ultra quiet applications insulate ductwork Exhausting through an outside wall is and mount fan over a less sound critical area often the best solution when penetrating the roof is not practical Illustrations show fan types typically used in these applications The specific fan model required depends on the conditions of each individual application 13 General Industrial Ventilation M 8 Intake Louvers Outside ai
29. ry the voltage supplied to the fan and slows it down a principle similar to the way dimmer light switches work 2 Models C CW and SQ have sizes 60 95 that are provided with 3 speed motors The three speeds are 1550 rpm D 1300 rpm G and 1050 rpm E Changing a motor lead is all that is necessary to change speeds When selecting a model with 3 speed motors it is recommended that the G speed be chosen whenever possible This is the middle speed which gives the greatest flexibility in air volume because airflow can be increased or decreased simply by changing a motor lead Typical Motor Tag Electrical Instructions Motor Speed Wiring Connections 1550 rpm White to L1 Black to L2 1300 rpm White to L1 Blue to L2 1050 rpm White to L1 Red to L2 Suffix Letter Motor Information Belt Drive Only When specifying a belt drive fan the model designation does not completely describe the unit Additional information about the motor is necessary These items are listed below Motor Enclosure This will be either Open open drip proof TE totally enclosed or EXP explosion resistant Open is the most common and will be supplied unless otherwise specified Accessories Speeds Motors are available in either single speed or two speed Single speed motors are 1725 rpm Two speed motors will be 1725 1140 rpm Single speed will be supplied unless otherwise specified Electrical Characteri
30. scscscsesessseeseeeenees 7 Cross Reference Chart sssssssssessesceeenseessenses 8 SECTION 2 FAN SELECTION BASED ON FAN APPLICATION Eer ge ele EE 9 Determining CAM 2esseeseeeuesE Eege esge Reeg eCeE See 16 Determining Static Pressure ssssscsssesseeseeees 17 SOUMNG Pevels EE 19 Motor Horsepower scscsssescsesseneeeeeeeeseseeeensenees 19 Installati n 2eccecsscccesssecesaseseccnsccecescccscasescucuccesescs 20 WheelRotatio m eese eere eneen eeann ER 20 SECTION 3 FAN PERFORMANCE FET NTE oop 21 System Dynamics e eRE ER EEEEREEREE EE KEE Ek Ek 21 Combining Fan and System Dynamics 22 Adjusting Fan Performance reen 23 Fan Laws wicccctoiicccscccsecccscescceccceeseseuuuuuescecaceeusen 24 INTRODUCTION TO FAN SELECTION This is the first and most basic of this manual s three sections all of which are designed to enable you to select the right fan for the job Look at this first section as a user s manual for Greenheck literature It will answer the following questions and more What is a SONE How are model numbers and performance tables used to select a fan How are direct drive and belt driven fans different What types of motors and accessories are used with these fans Are there Greenheck fans that will match the size and performance of fans from other manufacturers The goal is to understand and use the Greenheck literature as an important tool in filling a customer s fan order Terms cfm Cubic
31. stem is the point where these two curves intersect This intersection will determine the cfm and Ps delivered Adjusting Fan Performance There is a direct relationship between cfm and rom within a system Doubling the fan rpm will double the cfm delivered Sample problem The figure on page 21 showed a fan curve at 700 rpm which had an operating point of 1000 cfm at 0 25 Ps What rpm is required to move 2000 cfm through the same system Solution Within a system cfm is directly related to rpm Therefore the new rpm rpm can be determined from the following equation cima rpm rpm X Ei 700 rpm x Fan 1400 rpm 1000 cfm Referring to figure at right this results in sliding up the system resistance curve from 700 rpm to 1400 rpm Notice that as we doubled our airflow from 1000 cfm to 2000 cfm the Ps went up from 0 25 to 1 0 It must be kept in mind that we are not changing the system only increasing fan speed Therefore we must remain on the system resistance curve Within a system Ps varies as the square of cfm Since cfm and rpm are directly proportional an equation relating Ps and rpm can be derived as follows 2 _ rpms Ps Ps X Operating Point 0 7 0 6 0 5 0 4 Static Pressure 0 3 perating Point 0 2 0 1 8 10 12 14 16 18 CFM x 100 Varying Operating Points 3 5 3 0 2
32. stics Voltage and phase Voltage can be 115 208 230 or 460 Phase is either single or 3 phase A 115 volt single phase motor is shown as 115 1 Typically motors of 1 2 hp and less are single phase Motors of 3 4 hp and greater are 3 phase Most fans are ordered with accessories Here are some common accessories for selected models Model Roof Curb ESP Eaa Damper Roof Curb CUBE Kee Container SB Wall Mount Housing or Wall Mount Collar Common Accessories Model Common Accessories Speed Control Or een Discharge Vents Backdraft Damper SQ amp BSQ Backsirat Isolators Matching a Specification There will be times when a Greenheck model will have to be matched to a competing manufacturer s unit To aid in these circumstances we have provided a cross reference chart which includes our nine most common competitors If the manufacturer you need is not on this chart contact Greenheck for assistance To use the cross reference chart on next page start with the manufacturer at the top Then follow down until the model in question is found Follow across to the left to determine which Greenheck model is equivalent Once this is determined refer to the Greenheck catalog to find the best size to meet the specified performance Hint Typically when matching a Greenheck fan to a competitive model the size should also be matched If you are unsure of the size of the competitive unit compare fan rpm Fans of eq
33. sure increases cfm decreases If the pressure decreases cfm will increase At 700 rpm the operating point will slide along the fan curve as static pressure changes but it will never lie off the curve In order for a fan to perform at a point off the curve the rpm must be changed The figure below illustrates how rpm affects the fan curve Notice that the general shape of the curves are the same Changing rpm simply moves the curve outward or inward Varying Fan Curve 0 7 0 6 700 RPM 0 5 650 RPM 0 4 Static Pressure 0 3 0 2 0 1 0 2 4 6 12 14 16 18 8 10 CFM x 100 System Dynamics For a given flow rate cfm an air distribution system produces a resistance to airflow Ps This resistance is the sum of all static pressure losses as the air flows through the system Resistance producing elements include ductwork dampers grills coils etc A fan is simply the device that creates the pressure differential to move air through the system The greater the pressure differential created by the fan the greater the volume of air moved through the system Again this is the same principle that relates to water pumps The main difference in our case is that the fan is pumping air Tests have established a relationship between cfm and Ps This relationship is parabolic and takes the form of the following equation Ps K x cfm 2 Where K is the constant that ref
34. ual size should move approximately the same amount of air Model RSF and BCF Selection The RSF and BCF selection charts are different from all other selection charts For these models the cfm values are at the left side of the chart in a single column and the rpms are in the performance boxes It is just the opposite for other models The reason for this is that the RSF and BCF models are forward curved and the fan industry historically catalogs forward curved fans in this fashion Sample problem Choose the fan size and appropriate motor horsepower to move 980 cfm against 0 625 Ps Solution Refer to table below The first row in the chart corresponds to 980 cfm Follow across to the right to the 0 625 Ps column The performance box reveals that size 90 will meet this performance at 893 rpm and will require 0 20 Bhp Motor hp selection for forward curved fans is more complicated The Bhp is only 0 20 which suggests that a 1 4 hp motor is adequate However forward curved fans draw more horsepower at low Ps than at high Ps Assume this fan was running at about 893 rpm but instead of 0 625 Ps it was operating at only 0 25 Ps The new performance box in the 0 25 Ps column reveals 894 rpm at 0 45 Bhp The airflow would then be 1860 cfm Notice that as the Ps was reduced from 0 625 to 0 25 the Bhp increased from 0 20 to 0 45 This would burn out the 1 4 hp motor quickly With this in mind it is good practice to si
35. val aerer ENEE Sg SELECTING THE RIGHT FAN FOR THE JOB This book is designed to help you select the fan that will best fit the application for which it is intended With the large number of different fan types and sizes available it s necessary to know which fan model does the best job in certain applications and then to be able to select the most economical fan size for the job With that in mind this guide is constructed in three sections Section One describes how to select a fan using catalog performance tables with a given air volume and static pressure This section also interprets Greenheck model numbers and illustrates the relationship between fan speed and airflow Section Two covers the basics of fan selection determining the proper fan model air volume static pressure and loudness appropriate for a given application This is important when your customer does not know the amount of air to be moved or the resistance to airflow that will be encountered This section also illustrates proper fan installation and proper wheel rotation Section Three goes beyond fan selection with information of amore comprehensive and technical nature about air movement and air systems SIGREENHECK TABLE OF CONTENTS SECTION 1 INTRODUCTION TO FAN SELECTION TENE EE 4 Model Designation c cscscseseeeeeeeeeeseeeeeeeseennes 4 Reading Performance Charts s ssscsssssseeseeees 5 Matching a Specification
36. ze RSF and BCF motors at least one size larger than necessary based on the Bhp value in the performance box especially if the estimated Ps is questionable For this case an RSF 90 3 1 3 hp motor would be a good selection if we had confidence in the estimated Ps Otherwise use an RSF 90 5 1 2 hp motor RSF 90 4 1 4 hp motor is not recommended for this job STATIC PRESSURE CAPACITY MODEL orn See 0 125 0 250 0 375 0500 0 625 0 750 1 000 1 250 1 500 1 750 gan 1065 rem 521 630 725 812 893 967 Bhp 0 08 0 11 0 13 0 16 0 20 0 23 1200 1304 ep 593 685 771 849 925 994 1125 Bhp 043 0 16 0 19 0 23 0 26 0 30 0 38 4420 1543 PM 668 747 825 898 966 1031 1153 1267 1371 RSF 90 Bhp 0 19 0 23 0 27 0 31 0 35 0 39 0 48 0 57 0 67 1640 1783 TPM 746 819 887 953 1016 1077 1191 1298 Bhp 0 28 0 33 0 37 0 42 0 46 0 51 0 61 0 71 1860 2022 PM 828 894 954 1014 1073 1128 1236 Bhp 0 40 0 45 0 50 0 55 0 60 0 65 0 76 2080 2261 PM 910 970 1027 1080 1134 Bhp 0 54 0 60 0 66 0 71 0 77 4240 1097 PM 476 572 656 733 807 876 Bhp on 0 13 0 16 0 19 0 23 0 27 GE 1780 1575 TPM 605 679 748 813 873 931 1040 1143 1240 Bhp 0 24 0 29 0 33 0 38 0 42 0 47 0 56 0 66 0 77 2140 1894 PM 699 763 823 880 935 989 1086 1181 1269 1354 Bhp 0 40 0 45 0 50 0 56 0 61 0 67 0 78 0 89 1 00 1 12 Greenheck G CE CX CH ACE D
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