Rating tables and performance programs 41 selection and rating areas are defined by the manufacturers, usually only good selections are shown. Theoretical model for predicting axial fansblowers performance characteristics 3 l l 2 l 2 m v w2 r 2 m v w1 r 1 m v w2 r 2 3 m av f q, q av f m3s and a 4 2 d 2 1m2 m, is a constant mass flow rate between entry and exit. The fan s actual operating point on this curve will depend on the system resistance. Titus timeout podcast how to read a fan curves part 2 duration.
The second curve shows the relationship between the fans air volume flow rate and the brake horsepower. Trane applications engineers discuss fan performance curves and fan laws, different fan types fan blade shape, housed vs. All housings are rolled in our shop in farmington, new mexico, so quality will be topnotch. Performance data fch with ecm fan performance curves static pressure, inches w. Curves are normally supplied for each specific fan on a given project. Therefore, to change the angle of attack, the system to which the fan is attached must be changed. And flanges are 38 inch steel for greater strength. Study on pq curves of cooling fans for thermal design of. Characteristics and selection parameters of fans and.
Choose a fan that gives you the volumetric flow rate you need for your system pressure drop. Fan curves basics explained understanding fan performance curve. The performance curve describes a blowers ability to deliver flow rate against backpressure from zero backpressure open flow to completely blocked flow sealed. Note that the affinity laws for pumps are not identical with fans fan affinity laws.
At fan speed n1, the fan will operate along the n1 performance curve as shown in figure 5. For applications requiring a large air volume at a low static pressure, the bhp required at the fans operating rpm may not be sufficient to initially start. Once you select your cfm, draw a line vertically up to intersect the cfm vs sp curves that run from lower right to upper left. Computer software is available to provide selections and performance curves. The pressure is produced simply by the lift of the rotating blades as air moves over it. Locate some unit of pressure on the left hand sp scale 4 units and project a horizontal line to the point of intersection with the sp curve. Within each chart, there are a series of solid black lines with corresponding dashed lines. How to read a fan performance curve g squared engineered. The new york blower company is committed to supporting and supplying necessary equipment to meet the critical demands of the supply chains essential to aid america in this time of need.
The fan performance tables and curves in this catalog show the brake horsepower required to operate the fan once it is brought to speed. Mql units form eteg fan performance curves mql02 fan 0904 class i mql03 fan 0906 class i 16 envirotec mql modular airhandling units or et9e 45 mql06 fan 1209 class i mql04 fan 1007 class i envirotec 17 mql units form eteg. With adjustable pitch fans or belt drive fans that display multiple curves, you can calibrate between the curves for blade angle or rpm settings that are not givensee example. This action causes a new system performance curve sc2 where the required pressure is greater for any given air flow.
Development and testing of the characteristic curve fan model jeff stein, p. The fan is designed to produce a pressure difference, and hence force, to cause a flow through the fan. A fan operates along a performance given by the manufacturer for a particular fan speed. Figure 6 shows a fan curve of a fan with a significant dip in the stall region. The performance data contained in this catalog was calculated from tests conducted in accordance with amca standard 210 laboratory methods of testing fans for rating. Fan curves manufacturer will provide a fan curve for each fan he or she produces. All charts are organized by fan size and nominal motor rpm.
Although they can sometimes be used interchangeably with centrifugal fans, axial fans are commonly. Fan curves graphically depict fan performance data of cfm, rpm, sp, and bhp. Fan performance tables are at standard conditions 0. Fan curve density effects fan curves are developed for air at normal conditions 14. Continued and ever shortening product design cycles demand a get it right the first time approach. Rotron regenerative blowers performance curves regenerative. Factors which determine the performance of the fan include the number and shape of the blades.
Q is flow volume, a is impeller area, d is impeller diameter. Typical performance curves for a single impeller speed and diameter appear as. Fan not pulling full amps fan performance 80% of design fan sounded like it was hunting eg in stall initial diagnoses was uneven air on conditions due to transition pieces damper in front of fans disruption air flow on to blades. The first thing to note about the fan curve graph is that it has 3 axes. Development and testing of the characteristic curve fan model. Mcpherson 5 fan manufacturers usually publish characteristic curves in terms of fan static pressure rather than the fan total pressure. The vaneaxial fan figure 11 is a variation of the duct fan design which operates in the mediumtohigh pressure ranges. Fan affinity laws applies to all centrifugal loads flow proportional to the speed pressure proportional to the speed squared power proportional to the speed cubed speed % input power % 100 0 80 60 40 20 0 10 20 30 40 50 60 70 80 90 100. Engineers and designers who select and specify fans should have a good basic knowledge of fan curves and an understanding of how these are produced is vital for verifying the original fan selection, trouble shooting after the installation, and understanding future flexibility. Jan 16, 2019 being able to read a fan curve will allow you to choose the best fan for your requirements, as long as the fan is properly tested and certified. The system curve, the fan curve, and the operating point.
Performance improvement opportunity roadmap 1assessing fan system needs 17 2 fan types 19 3basic maintenance 25 4common fan systems problems 29 5indications of oversized fans 33 6system leaks 37. To access this material simply click on the link or to save right click and select save target as. Fan performance curves the performance curves for these fan types have been established in mounting position d according to amca 210, installed on the pressure side and suction side and represent the total pressure increase dp t as a function of the volume flow. For a more indepth look into the characteristics of different fan types, refer to fe2300 for axial fans and fe2400 for centrifugal fans.
I will write something next on how to draw a system curve. The dynamic pressure p d2 refers to the flange crosssectional area at the of the. The fan supplier will then select a suitable sized motor to the fan. In addition to being more useful for ventilation planning, this is. The fan performance chart shows performance curves for a series of fan speeds. The upfront use of system curves, fan curves and fan laws can help meet this goal. Knowledge of fan performance curves, and how they are obtained, allows for a more informed decision when selecting a fan. The solid black lines represent the fan curves for each fan and are broken down by partial wheel widths. In a fan, the blades are normally rotating at constant velocity. At fan speed n 1, the fan will operate along the n 1 performance curve as shown in figure 5.
The fans actual operating point on this curve will depend on the system resistance. Static pressurehorsepower curve backward inclined centrifugal even though the performance curves for the vaneaxial fan and the centrifugal fan have completely different shapes, the curves are read in the same way. Member ashrae member ashrae jeff stein is a senior engineer and mark hydeman is a principal at taylor engineering, llc, alameda, calif. Page 14 performance data determination the fan performance section of this catalog contains a fan performance table and fan curve for each fan size. Fan performance other than that anticipated when the fan was initially selected less flow, higher pressure, greater power consumption due to reduced fan efficiency. The performance of the vaneaxial fan figure 12 shows the pressure curve to rise steeply from free. Various axial and centrifugal fan performance curves will be illustrated throughout this article with no attempt made to rationalize any particular selection. Fans and blowers bureau of energy efficiency first method is to restrict the air flow by partially closing a damper in the system.
Higher flow rates through the inlet increase the attack angle, and. Study on pq curves of cooling fans for thermal design of electronic equipment effects of opening position of obstructions near a fan january 2011 doi. Fdc fan curves1 v001 performance data fdc with ecm fan performance curves unit size 10 static pressure, inches w. For complete product specifications and submittal data isit us at. Performance curves housings on all fans are constructed out of 14 inch steel plate.
The performance curves shown in this catalog represent each models typical maximum performance full speed at a constant input voltage. The fan ttotal eefficiency can be calculated by using the formula. The affinity laws for centrifugal pumps and fans are used to express the influence on volume capacity, head pressure andor power consumption due to. Being able to read a fan curve will allow you to choose the best fan for your requirements, as long as the fan is properly tested and certified. These types are characterized by the path of the airflow through the fan. Fan laws and system curves new york blower company. This flier provides a brief overview of the fans and blowers industrial air technology corp. Fan curves one of the most valuable pieces of information supplied by fan manufacturers is the fan performance curve. Characteristics and selection parameters of fans and blower. Choose a fan that has its peak efficiency at or near your operating point.
Performance data intermittent volume parallel flow, low profile design external static pressure 0. Factors which determine the performance of the fan include the. The air is pressurized by the aerodynamic lift generated by the fan blades, much like a propeller and an airplane wing. These curves are observed to have the following characteristics. The following performance charts are for the selection of qeid mixed flow inline fans. Reducing or increasing the fans rotational speed respectively reduces or increases the height of the fans characteristic curve as exhibited on the example curves below. The fan curves predict the pressureflow rate performance of each fan. Introduction to fan systems fans 3 fan performance curves 6 fan system components 9 section 2. An axial fan is a type of fan that causes gas to flow through it in an axial direction, parallel to the shaft about which the blades rotate. The fan will now operate at b to provide the reduced air flow q2 against higher pressure p2. These curves show the relationship between the quantity of air a fan will deliver and the pressure generated.
The performance curve describes a blowers ability to deliver flow rate against backpressure from zero backpressure open flow to. Two to 10 inches water gauge is the expected pressure range for a single stage fan. The article has explained the fan curves basics, but drawing correct system curve is not a easy task and selecting the fans operating point depends largely on preparing correct system curve. When your system curve intersects the cfm vs sp curve this is indicative of that fans performance when applied to your actual system. Blower application basics blower application basics. Technical how to read performance curves axair fans.
1125 384 769 1267 553 1431 729 148 1284 130 798 658 1042 1276 1039 1178 1565 350 341 34 966 96 1439 1021 692 634 1399 1116 1440 966 1168 1279 584 1551 320 816 748 860 768 931 529 925 589