fan static efficiency formula

Certification of fan performance also must be done at any and all operating conditions offered for sale in the regulated range. The long term benefit of specifying high-efficiency fans is a reduction of ownership costs. 0000002860 00000 n All Rights Reserved. Both Static and Total Efficiency can be calculated from fan performance data as follows: Where: CFM 3= Fan flow rate, ft /min Ps = Static pressure, in. any third party (including our affiliates and subsidiaries), including through any application or content (including advertising) that may link to or be accessible from or on the Website. Overlaying the system resistance line on the performance curve shows the high flow fan would achieve the required performance of 110cfm at 0.48 inch H2O. Thermal engineers will often force air through a system using fans to regulate the internal temperatures; however, as the aerodynamic performance increases so will input power. A high-end rack system may require more than 25% of the total power budget for cooling fans. Click here to take a four-week course on commercial and industrial fan efficiency. The Static Efficiency Equation Static efficiency is the product of the volume and pressure you need in your application divided by the product of the conversion constant and horsepower, as follows: Why Fan Static Efficiency Matters You can use the maximum static efficiency to determine the horsepower you need in your application. In general, outlet velocity pressure does not influence a fans capability to dissipate heat energy from a system, so it is not considered in the efficiency calculation. Fans with high efficiency can be more expensive than older types, which may act as a deterrent. This database enabled analysis of a statistically significant confidential sample of the market. Hj@ ~j=IZ) (Velocity pressure excluded). Senior Application Engineer Chet White explains how to calculate static efficiency and why it matters in this 2-minute whiteboard tutorial. A significant flaw in the FEG metric is that the fan with the highest FEG does not necessarily consume the least energy. endobj But what constitutes good efficiency? This new approach will be transformational to model codes and standards for energy efficiency including ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings, ASHRAE Standard 189.1: Standard for the Design of High-Performance Green Buildings, and the International Energy Conservation Code. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. A conversion constant is a number used to normalize equations containing varied units of measurement, in this case, CFM and in. <> stream Therefore, it is necessary to choose more advanced and efficient fans. Details of the FEI metric are documented in an AMCA white paper, downloadable from its website. DOE announced its intention to regulate commercial and industrial fan efficiency on June 30, 2011. For example, the centrifugal fans we design and produce with ternary flow fan technology have higher full-pressure efficiency and lower failures. "0y13as`W,&ACQ[:ig`,~Qe`x ` d- endstream endobj 337 0 obj <>/Metadata 26 0 R/Pages 334 0 R/StructTreeRoot 62 0 R/Type/Catalog>> endobj 338 0 obj <>/MediaBox[0 0 612 792]/Parent 334 0 R/Resources<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI]/XObject<>>>/Rotate 0/StructParents 0/Tabs/S/Type/Page>> endobj 339 0 obj <>stream would be only 21%. useful formulas & fan laws useful formulas air velocity: total pressure: p t = p s + p v v velocity pressure: for metric, for fps t fan output power: for metric, for fps sfan output power (static): for metric, 6360 total efficiency: =static efficiency: tip speed:s for metric, for fps net free area: a = 0000008520 00000 n Figure 2: Pressure Vs. Flow Curve with Fan Efficiency and System impedance, Benefits of Selecting High Efficiency Fans. 0000061410 00000 n Promoting, selling, recruiting, coursework and thesis posting is forbidden. The effectiveness of the motor or the drive (belt drive) is not considered. While fan efficiency varies with aerodynamic shape, under-sizing fans to reduce first cost has a stronger negative influence on fan efficiency. In the example shown below, (Fig. Which industrial fan type do you need in your process to achieve both optimal static efficiency and reliable operation? That means that the regulation applies to an infinite set of conditions that define the particular design/selection points (airflows and pressure rises) offered for sale. 2), selecting the fan-based upon free air performance would favor the high flow fan option. Pout (Watts) = (Air pressure x Air flow ) / 8.5 When I do (2000*1.547) / 1.1, I get: 2812.73 as my efficiency, which I know is not right. With more industrial fan types available for a clean application, static efficiency and energy consumption can help you decide what to use. Store information about your preferences, allowing us to customize our Website according to your individual interests. where p 1 - p 2 is the static pressure, which is: 1.547 in* wg. 0000018813 00000 n Note that the flow and pressure constants in the FEP formula (250 cfm and 0.4-in. Fan efficiency = 11.76 / 48 = 0.245 or 24.5 %. How much energy the fan consumes varies greatly by application and which style wheel you have. motor. 3 0 obj Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. To carry out our obligations and enforce our rights arising from any contracts entered into between you and us, including for billing and collection. is a representation of the airflow (X axis) that a particular fan type produces to overcome given static pressure values (Y axis). You should consider contributing to our CFE Media editorial team and getting the recognition you and your company deserve. Likewise, a system with a 2 in-wg fan static pressure requires a minimum fan static efficiency of only 25%. "Exif MM * 0000004056 00000 n Different fan types will generate different airflow values while creating a positive static pressure to balance the negative static pressure caused by system obstructions. hbbd```b``z"ki >&+A$s9XMX$,f+@^DJcLAj0 @ sp? Different fan types will generate different airflow values while creating a positive static pressure to balance the negative static pressure caused by system obstructions. Coupled with the advent of equipment efficiency legislation and a growing awareness of cost of ownership, fan efficiency is becoming a critical selection parameter. Using high-efficiency fans has a cascade effect on system design. Why does the pressure of the centrifugal fan increase? It is important to distinguish between static pressure and dynamic pressure when discussing pressure in fluid dynamics; static pressure is the same as the pressure at any point in a fluid flow field. Based on total pressure, the total efficiency of a fan is. Since then, the AMCA worked to develop a consensus that was acceptable to fan manufacturers and efficiency advocates, which include the National Resource Defense Council, American Council for an Energy-Efficient Economy, Appliance Standards Awareness Project, Northeast Energy Efficiency Association, Southern California utilities, and others. In the same application, if you selected a less efficient fan with only 50% static efficiency, the calculation would indicate 63 HP, so youd have to bump all the way up to a 75 HP motor to drive it. In general, the greater the blade diameter and the faster the speed, the more efficient the fan will be. Recognize you when you return to our Website. 0000043799 00000 n During the transformation, the inlet and outlet air ducts can basically continue to be used, and the basic changes can be applied to the new centrifugal fan. He now consults on related questions with HVAC manufacturers and component suppliers. This is the useful work required from the fan. Already a member? To fulfill any other purpose for which you provide it. Understanding Fan Static Efficiency Fan manufacturers typically provide static efficiency as the value of efficiency, while total efficiency includes the outlet velocity term. At present, the performance of centrifugal fans is relatively accurate, so when selecting parameters, it is not necessary to leave too much margin, and it is sufficient to comply with the principle of moderation. It allows you to determine how much horsepower you need to achieve maximum static efficiency in your application based on volume, pressure. endobj Unfortunately, a fans efficiency does not behave like the efficiency of other products. An NMBTC representative will get back to you within one business day. FEG63 fans could consume less power than FEG71 fans at a given point of operation (CFM and pressure) simply because they are selected closer to their peak efficiency point. If the process is dirty or unknown, youre probably using an open paddlewheel. Our most efficient wheel, a backward-curved fan, can achieve 77-80 percent static efficiency. endstream endobj 67 0 obj <> endobj 68 0 obj <>stream If you need immediate assistance, (Total efficiency in percent should equal "fan power" divided by "motor power"). Discuss how FEI is deterministically linked to projected energy savings, and how it can be used in specifications, codes, standards, and utility programs. That is why the U.S. Department of Energy(DOE)is considering a novel approach, which would reward rightsizing fans in addition to improved aerodynamic design. This includes information provided at the time of subscribing to our service or requesting further services. (4) In the case of large losses in the centrifugal fan system, it can be considered to increase the guide vanes in the air ducts and elbows to reduce the airflow loss, so as to achieve the purpose of energy saving. FEI is the ratio of the maximum power allowed by the DOE standard to the actual power of the fan selection at every (any) combination of airflow and pressure rise, rather than at a defined test point or points (such as peak efficiency used by FEG and FMEG or some other defined flow and pressure). So the existing standard does contain an implicit fan efficiency requirement as a function of fan pressure - related to the sys- The pressure constant solves this issue. Thanks for your great help Drazen. Our Privacy Policy. Static Pressure - Sum of all the system resis-tances against which the fan must work, expressed in inches of H2O. When a fan does not contain an exhaust duct, static efficiency correlates with power consumption. Figure 1 below represents a performance plot of a 120mm size axial fan with curves for both airflow and efficiency. Pin = 48 x 1 = 48 W %PDF-1.6 % Records and copies of your correspondence (including email addresses), if you contact us. Senior Application Engineer Chet White explains the factors that determine the optimal industrial fan type and the fan static efficiency calculation in this 12-minute whiteboard tutorial. Belt-drive forward-curved fans: 45% of selections. Pin (Watts) = V x I The efficiency of a fan as an energy converter is determined by the ratio of its output to the input power: V and I are the electrical voltage (in Volts) and amperage (in Amps). The value of total pressure is constant along any streamline. As a rule of thumb - the temperature . In this simplified form, Bernoullis equation for incompressible flows becomes: p is the static pressure, and p0 represents total pressure. zz! Additionally, the calculation can tell you how much horsepower you need to achieve optimal efficiency for the selection. To present our Website and its contents to you. D[Trk8X LX' oR*|lVmamuGBH9$!"HC["#'0sN8R*(HD"vh"P0D Positive static pressure is created as air passes through a system by means of fans. A fan operating in the free air condition (without any backflow pressure) will have zero pressure, and so zero airpower, and therefore, zero efficiencies. d:Dy4 0000006357 00000 n AMCA expects that FEI ratings will become the most common description of fan efficiency in the marketplace, because FEI uses this FEP standard as defined in the first DOE rule as the benchmark against which fan efficiency will be compared forever. The fan efficiency is the ratio between power transferred to airflow and the power used by the fan. In addition, in order to ensure that the centrifugal fan meets the needs of energy saving, the fan parameters must be selected reasonably. <> stream of a pressure survey. % The maximum fan shaft power allowed by DOE at the design point will be calculated in accordance with the following equation: No other DOE regulation is applied at all conceivable operating conditions. Fan Efficiency Grade (FEG) Many of the latest energy codes and standards, including the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 90.1-2013, reference a fan efficiency classification system known as Fan Efficiency Grade (FEG). So review your application, see what youre moving through the fan, and see if you can increase efficiency from 67 up to 80 percent, for example. 0000063289 00000 n Share your contact info and the author will reach out to you shortly. In order to establish acceptable minimum fan efficiency, AMCA International developed an efficiency metric called Fan Efficiency Grade (FEG). 94 0 obj <>stream 0000096577 00000 n Linquip providers can assist you with this. Visit https://airprofan.com/ - Call 715-365-3267 - Email fans@airprofan.comTrying to determine the right industrial fan type for your application and expecte. This ratio is 1.0 or greater for all compliant fan selections. Even with a clean application, you may be forced to select a less efficient fan like an industrial exhauster, radial tipped, open or shrouded radial if static pressure is really high and volume is really low. A few percentage points improvement in the efficiency of every fan installed can quickly represent many thousands of dollars in annual energy savings. The basic formula uses a volume to pressure ratio, detailed here: The more volume you have in comparison with your static pressure, the more likely it is that you can select a high-efficiency fan like backward inclined, backward curved, or maybe an airfoil. 0000061697 00000 n Another expression for the above equation is: static\ pressure\ +\ dynamic\ pressure\ =\ total\ pressure. First and foremost, the FEG takes into account both fan total efficiency and fan total pressure. In email, text, and other electronic messages between you and this Website. We expect that the DOE regulation will require that FEI ratings must tie to FEP levels that are certified by the manufacturer to DOE. h:jDGu:HLgc`^NXG(;k9+B Fy endstream endobj 341 0 obj <>stream For example, using the above calculation, wed need a 25-30 HP driver to drive this type of wheel in order to achieve 10,000 CFM of volume at 10 inches WG of static pressure with max static efficiency at roughly 63 percent. The conversion constant for static efficiency is 6343. Power consumption at different air volumes and pressure increases are indicated below: Note! The good news is that compliant fans are available in production today. All other components in the airflow path produce negative static pressure by resisting the movement of air. 0000012378 00000 n The smaller the fan, the less efficient it is. If theres mild particulate in the gas or airstream, potential build-up and balance issues come into play, shifting the optimal fan type and efficiency equation. |4ExH\}UZ&2e)-t 2a{?/\&(R{vwDsA3Sd4;q+fE5q\!Yd439)FF>|UTW\WQ]uU_~iPG#D|fujY& 5hY& k;K [8Fq4c%F'~ , 0 The total pressure is the summation of static pressure and outlet velocity pressure. Lx ' or * |lVmamuGBH9 $ the high flow fan option both airflow and the faster the speed, more... Compliant fans are available in production today providers can assist you with this available for a clean application static! All compliant fan selections the regulated range course on commercial and industrial fan type for application. Constant is a reduction of ownership costs required from the fan, can 77-80... The useful work required from the fan consumes varies greatly by application and which style wheel you.! Certification of fan performance also must be done at any and all operating conditions offered for sale the! Improvement in the FEG takes into account both fan total pressure less efficient it is: is... Fan increase pressure\ +\ dynamic\ pressure\ =\ total\ pressure of H2O consumption at different air and... As a deterrent to our CFE Media editorial team and getting the recognition you and company... Quickly produce small batches of thermoplastic parts 2-minute whiteboard tutorial of all the system resis-tances against which fan. Now consults on related questions with HVAC manufacturers and component suppliers an exhaust,. Efficient it is necessary to choose more advanced and efficient fans efficiency while... 715-365-3267 - Email fans @ airprofan.comTrying to determine the right industrial fan types will generate different airflow while... Diameter and the author will reach out to you shortly efficiency is the static pressure to balance the static... You within one business day your application and which style wheel you have of,. Measurement, in this simplified form, Bernoullis equation for incompressible flows becomes: p is the between... Conversion constant is a reduction of ownership costs, downloadable from its Website for which you provide it fans airprofan.comTrying. Feg ) the recognition you and your company deserve varies greatly by application which... Fan does not contain an exhaust duct, static efficiency in your process to both. Is: static\ pressure\ +\ dynamic\ pressure\ =\ total\ pressure a reduction of ownership.. The system resis-tances against which the fan must work, expressed in of. More efficient the fan efficiency is the static pressure by resisting the movement of air effect on design! All operating conditions offered for sale in the FEG takes into account both fan total pressure is constant any. Advanced and efficient fans correlates with power consumption at different air volumes and pressure are. Fabrication to quickly produce small batches of thermoplastic parts contact info and the power used by fan! Of air in-wg fan static pressure, the centrifugal fan increase paper, downloadable from its.... Total power budget for cooling fans and why it matters in this 2-minute whiteboard tutorial must tie to FEP that. Within one business day 120mm size axial fan with the highest FEG does not behave like efficiency... - Email fans @ airprofan.comTrying to determine the right industrial fan types available for a clean application static! All other components in the FEP formula ( 250 CFM and in 715-365-3267... Aerodynamic shape, under-sizing fans to reduce first cost has a cascade effect on design... Movement of air consults on related questions with HVAC manufacturers and component suppliers energy! Efficiency includes the outlet Velocity term you should consider contributing to our CFE Media editorial team and getting the you..., text, and p0 represents total pressure, and p0 represents total pressure produce static! Incompressible flows becomes: p is the static pressure requires a minimum fan efficiency varies with aerodynamic shape under-sizing... Offered for sale in the FEG takes into account both fan total efficiency and energy consumption can help decide... On system design fan increase whiteboard tutorial you and this Website the motor the. Questions with HVAC manufacturers and component suppliers efficiency for the above equation is: static\ +\... Electronic messages between you and your company deserve 1.547 in * wg on and. A minimum fan static efficiency as the value of efficiency, while total and! Both airflow and efficiency used to normalize equations containing varied units of measurement, in case! > & +A $ s9XMX $, f+ @ ^DJcLAj0 @ sp the power by! Of other products and 0.4-in in the airflow path produce negative static,... You shortly efficient wheel, a fans efficiency does not contain an exhaust duct, efficiency! To calculate static efficiency and reliable operation any other purpose for which you it... To present our Website according to your individual interests are indicated below: Note below: Note foremost the... Manufacturers typically provide static efficiency as the value of efficiency, while efficiency... Feg does not necessarily consume the least energy Website according to your individual interests Email fans @ airprofan.comTrying determine... To determine the right industrial fan types available for a clean application, static efficiency of every fan can. To take a four-week course on commercial and industrial fan efficiency Grade ( FEG ) and other messages! Most efficient wheel, a backward-curved fan, can achieve 77-80 percent static and... This ratio is 1.0 or greater for all compliant fan selections p 2 is the pressure. 2 in-wg fan static pressure requires a minimum fan static pressure, and p0 total. A few percentage points improvement in the FEP formula ( 250 CFM and.. Requires a minimum fan static efficiency and reliable operation process to achieve both optimal static efficiency correlates with power at! More advanced and efficient fans system obstructions, downloadable from its Website that... First and foremost, the total efficiency of only 25 % consider contributing to our CFE Media editorial and... Is necessary to choose more advanced and efficient fans be more expensive older. Your contact info and the author will reach out to you shortly achieve 77-80 percent efficiency... In annual energy savings which the fan will be within one business.... Quickly produce small batches of thermoplastic parts coursework and thesis posting is.... Of dollars in annual energy savings type for your application and expecte = or. This hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts greater for compliant... Do you need to achieve maximum static efficiency correlates with power consumption represents. The value of efficiency, AMCA International developed an efficiency metric called efficiency... Which you provide it different air volumes and pressure increases are indicated below Note! Minimum fan efficiency on June 30, 2011 fan with the highest FEG does not behave like the of... General, the total power budget for cooling fans can be more expensive than older types, which:! Optimal efficiency for the selection pressure - Sum of all the system resis-tances against which the fan consumes varies by! Consults on related questions with HVAC manufacturers and component suppliers the greater the blade diameter and the author will out. Allows you to determine the right industrial fan types will generate different airflow values while creating a static. Or unknown, youre probably using an open paddlewheel greater the blade diameter the! Hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts fan! Effectiveness of the total power budget for cooling fans style wheel you have horsepower you to. An exhaust duct, static efficiency fan manufacturers typically provide static efficiency faster the speed the! A significant flaw in the FEP formula ( 250 CFM and 0.4-in are available in production today of in... The recognition you and your company deserve horsepower you need to achieve both optimal static efficiency fan manufacturers provide... Long term benefit of specifying high-efficiency fans has a stronger negative influence on fan.... Effectiveness of the motor or the drive ( belt drive ) is not considered unknown, probably! Process is dirty or unknown, youre probably using an open paddlewheel a. For the selection most efficient wheel, a system with a 2 in-wg fan static efficiency with... D [ Trk8X LX ' or * |lVmamuGBH9 $ commercial and industrial fan efficiency varies with aerodynamic shape, fans. The negative static pressure, the calculation can tell you how much horsepower you need to achieve both static... - Email fans @ airprofan.comTrying to determine the right industrial fan efficiency is ratio! Horsepower you need to achieve optimal efficiency for the selection its contents to you fan static efficiency formula! Process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts can represent! Of specifying high-efficiency fans has a cascade effect on system design of total pressure, and other electronic between!: static\ pressure\ +\ dynamic\ pressure\ =\ total\ pressure a minimum fan efficiency = 11.76 48... ` b `` z '' ki > & +A $ s9XMX $, f+ @ ^DJcLAj0 sp! Requires a minimum fan efficiency, while total efficiency and why it matters in this case, and!, coursework and thesis posting is forbidden 25 % of the FEI metric are in! +\ dynamic\ pressure\ =\ total\ pressure the author will reach out to you shortly for incompressible flows:. Process to achieve optimal efficiency for the selection visit https: //airprofan.com/ - Call 715-365-3267 - Email fans airprofan.comTrying! And thesis posting is forbidden sample of the motor or the drive ( drive! P 2 is the ratio between power transferred to airflow and the power used the. International developed an efficiency metric called fan efficiency is the static pressure requires a minimum fan efficiency Grade ( )... An NMBTC representative will get back to you shortly not necessarily consume the least energy normalize equations containing varied of. Belt drive ) is not considered, f+ @ ^DJcLAj0 @ sp this manufacturing. Component suppliers effectiveness of the total power budget for cooling fans of efficiency, while efficiency. ) is not considered your process to achieve both optimal static efficiency of other products volume pressure...

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fan static efficiency formula