typical fan efficiency

They need to get the dust-laden air past the filters in the dust collector baghouse. The first thing to note is that the “fan efficiency” is for the complete fan assembly, including impeller, drive motor and VSD (if fitted). Figure 1 shows a typical fan curve (green) with two numerated system lines (dashed), and the rated efficiency curve. Given their size, it’s not surprising house fans consume more power than ceiling fans. What this means is that for a fan handling standard atmospheric air with a density of 1.2 kg/m3 and a static efficiency of 75% the maximum pressure rise over the fan is 22.5 kPa. The Fan Total Efficiency field (simply 'Fan Efficiency' in OpenStudio) will need to be adjusted to represent the change in motor efficiency and fan power consumed. Typical ranges of fan efficiencies are given in Table 5.2. The fan efficiency is the ratio between power transferred to airflow and the power used by the fan. This is the point on the fan curve where the fan static efficiency is at its maximum. They represent the year’s very best for energy savings and environmental protection. ): Velocity Pressure: Flowrate (CFM): Cross Sectional Flow Area (sq. We do this regardless of actual installation of the fan which could be B,C or D because the vast majority of fans we supplied with a contractual static pressure requirement. Static Fan Efficiency = Volume (m3/s) * Pressure gain (Pa) / Power input (W) * 100 But, if the pressure is measured in mmWC instead of Pascals and Power is expressed in kW, the formula can be derived as follows;- 1 mmWC = 9.81Pa Therefore 1Pa = 1/9.81 = 0.102 mmWC (or, divide mmWC by 0.102 to get Pa) As specified in EU 327/2011 efficiency calculations are based on “best efficiency point”. The total efficiency of the fan at the design point of operation shall be within 15 percentage points of the maximum total efficiency of the fan. Woodcock & Wilson 600mm dia BFN Single Inlet Single Width (SISW) fan running at 2000 rpm. ?_t=transmission drive efficiency=0.96 (clause 3.2 annexII) An inline water pump works between pressure 1 bar (1 105 N/m2) and 10 bar (10 105 N/m2). Fans where the work per unit mass exceeds 25 kJ/kg. As the overall efficiency is > than target efficiency fan is compliant. All fans are supplied as a complete assembly. 1353953 | VAT No. All applications of fans in ventilating, cooling, heating, and air conditioning processes have their unique set of environmental factors that dictate the fan design, but few are as restrictive as an engine cooling fan. Type of fan Peak Efficiency Range Centrifugal Fan Airfoil, backward curved/inclined 79-83 Modified radial 72-79 Radial 69-75 Pressure blower 58-68 Forward curved 60-65 Axial fan Vanaxial 78-85 Tubeaxial 67-72 Propeller 45-50 Syllabus Fans and blowers: Types, Performance … Static efficiency at best efficiency point 75.8%. © Woodcock & Wilson Limited 2020 | Website Terms & Conditions | Privacy Policy | Site Map, Energy Efficiency & ERP for Woodcock & Wilson bespoke Industrial Fans, Fans for use in potentially explosive atmospheres. ft.) Velocity Pressure (in. Cookies are only used in the browser to improve user experience. Note this is not an exhaustive list. The overall efficiency is the ratio of power actually gained by the fluid to power supplied to the shaft. In absence of specific information regarding vee belt drives, if fitted, these will be calculated using clause 3.2 of Annex II of  EU327/2011 “low efficiency drive”. Step 1 Work out “target efficiency” using table 2, “Centrifugal backward curved fan with housing” measurement category A,C Efficiency category “static”, Electrical input power will be less than 10 kW (note this is not the motor power it is the actual power drawn by the fan despite motor rating), N = Efficiency grade from table 2 (right hand column) 61. Industrial fans have a special job to do when used in a dust collection application. Even if for example the motor is free issued we can use the correct motor efficiency supplied by the customer, or in the absence of this, then the minimum required motor efficiency eg IE2 or IE3. Most of the fans were in the 60 to 75 cfm/watt range. Note items 9 & 10 of the above clause are not relevant to bespoke fans where the performance is derived from fan tests and scaled using dimensionally similarity fan laws. Step 2 work out the fans actual efficiency using clause 3.1 Annex II, P_us=q × p_sf×k_sp P_us=2.81 × 2080×1.0=5844.8, Pe cannot be measured therefore is calculated as follows, P_e=impeller power×1/?_m ×1/?_t ×1/?_vsd ×?1/C?_c, ?_m=motor efficiency=0.914 IE3 11 kW 4 pole Fans shall have a Fan Efficiency Grade (FEG) of 67 or higher based on manufacturers’ certified data, as defined by AMCA 205. By replacing a less efficient model with a highly efficient one, it is possible to save on average around 20% of its running costs during its lifetime (15 years). Due to leakage of fluid between the back surface of the impeller hub plate and the casing, or through other pump components - there is a volumetric loss reducing the pump efficiency. Mechanical components - like transmission gear and bearings - creates mechanical losses that reduces the power transferred from the motor shaft to the pump or fan impeller. Because airpower is the product of flow and pressure, a fan working in the free air condition (no backflow pressure) has … Fans for use with toxic, corrosive or flammable gasses or subject to abrasive substances. New fan-efficiency metrics developed by AMCA International—fan energy index (FEI) and fan electrical power (FEP)—can be used to right-size fans and reduce power consumption in commercial and industrial air systems. Some of our calculators and applications let you save application data to your local computer. C_c=Part load compensation factor= 1.04 Centrifugal fans often contain a ducted housing to direct outgoing air in a specific direction or across a heat sink; such a fan is also called a blower, blower fan, biscuit blower [citation needed], or squirrel-cage fan (because it looks like a hamster wheel). We don't save this data. ANSI/ASHRAE/IES 90.1-2013 requires fans have a fan-efficiency grade (FEG), as defined in AMCA 205, Energy Efficiency Classification for Fans, of 67 or higher. These applications will - due to browser restrictions - send data between your browser and our server. Drive loss is based on full load motor power (11 kW) ie Pa = 11 kW, VSD power Taken as motor full load power ie Ped = 11 Kw, Registered in England No. ERP is a European Union (EU) for Energy-Related Products. The propeller efficiency curve shown in Figure 1 is a composite of both the typical Bonanza two and three blade propellers at two different conditions. (The vertical line joining the maximum efficiency point is drawn which meets the Pressure curve at point "S") [1] The following can be inferred from the curve - What this means is that for a fan handling standard atmospheric air with a density of 1.2 kg/m3 and a static efficiency of … en: pump fan efficiency power shaft fluid. 6.5.3.1.3 Fan Efficiency. When evaluating your fan, the fan curve can be a useful tool to understand why the efficiency may be low at the given operating point. hp to an exhaust fan when operated at its full rated speed. The mechanical efficiency can be expressed as: ηm = (P - Pl) / P                              (2), P = power transferred from the motor to the shaft (W). The fan efficiency is in general independent of the air density and can be expressed as: μ f = dp q / P (2) where. For this CalQlata has tried to keep the operation of this calculation option as simple as possible, given that it is recommended for general purpose calculations only and not for actual purchase specifications (see Fan Calculator – Technical Helpbelow). For example a given fan could be supplied with a dozen different motors, be direct or belt driven. P_e=7.71×1000×1/0.914×1/0.96×1/0.98×1/1.04, Step 3 compare calculated efficiency with target efficiency. The actual efficiency of a fan depends on its power requirement (high power fans are on average more efficient than low power fans) and type. The typical characteristics of axial fans can be studied from the performance curves. Fan noise 7/12/2000 11.2 Fan Application The choice of a fan depends on the desired ventilation requirements (volume, … Fan efficiency = 11.76 / 48 = 0.245 or 24.5 % The Fan Efficiency Curve Fan efficiency varies dramatically as a function of aerodynamic loading. Products that make the ENERGY STAR Most Efficient list for 2020 deliver cutting edge energy efficiency along with the latest in technological innovation. Also, actual installed efficiency is typically worse than the manufacturer's rating data indicates, dropping the fan's efficiency by 10 to 30 percent in some cases. A centrifugal fan is a mechanical device for moving air or other gases in a direction at an angle to the incoming fluid. The “S” denotes the selection point for the desired performance. As a rule of thumb - the temperature increase in a fan transporting air is approximately 1oC. No high performance alternatives. Absorbed power (of the impeller) is 7.71 kW. We don't collect information from our users. One factor that affects this number is how big the fan is. Google use cookies for serving our ads and handling visitor statistics. Centrifugal fans are typically used for lower flows and higher pressures. The volumetric efficiency can be expressed as: ηv = q / (q + ql)                               (3), q = volume flow out of the pump or fan (m3/s). Currently we use the requirements set out for 1st  January 2015 onwards. Fan Total Efficiency = Motor Efficiency * Fan Efficiency, so you can adjust your fan total efficiency accordingly if you know the change in motor efficiency. Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications! This paper provides an analysis of costs and benefits of several options to improve the efficiency of ceiling fans to assess the global potential for electricity savings and green house gas (GHG) emission reductions. The use of a “systems approach” in the fan selection process will typically yield a quieter, more efficient, and more reliable system. Fans fall … Fig 2shows the pressures through a fan, each of which is described below: Inlet Pressure; is the static pressure on the inlet side of the fan. Commonly known as ATEX fans, Fans designed for operation with high temperature air above 100OC, Where ambient gas temperatures exceed 65OC or fall below -40OC, Where the supply voltage to the drive motor >1000 V AC or 1500 V DC, Fans for use with toxic, corrosive or flammable gasses or subject to abrasive substances. The overall efficiency can be expressed as: η = η h η m η v (4) where. If you want to promote your products or services in the Engineering ToolBox - please use Google Adwords. ENERGY STAR Certified Most Efficient 2020 Ceiling Fans. Please read AddThis Privacy for more information. Is there a way to fine tune the rule of thumb for a specific aircraft and propeller? As a rule of thumb - the temperature increase in a fan transporting air is approximately 1 o C. Example - … ?_vsd=variable speed drive efficicney if fitted=0.98 (estimate) Target total efficiency of fans according to requirements of EU fan regulation. Most industrial fans that fall between the above input power limits are covered by EU 327/2011. Kps compressibility coefficient of fan static gas power taken as 1 as this is already calculated in the fan testing carried out to BS EN 5801. Energy-efficient whole-house fans. The efficiency of the fan is affected by the annular clearance between the impeller and the scroll case and between the impeller and a point called a cutoff. This is then corrected using the fan laws to derive performance for different sized fans running at different speeds and operating at different densities. Stay tuned to be able to search FEI rated fans … Note that compliance with EU 327/2011 is based on calculation, as we manufacture bespoke one off units individual fan tests are not possible. It is not necessarily the fan operating point, though generally we aim to select fans at or near this point. typical ventilation rate of 10 m³/h per m² floor, and a typical SFP of 3.kW/(m³/s), operating 4 3000 hrs/yr, the fan energy accounts for: m²yr kWh 28 yr h 3000 m³/s kW 3.4 3600s 1h m² m³/h 10 × × × = which is 17% of the total energy use of an efficient (lower quartile) existing office building . Drive mechanism Direct drive fan/motor combinations are the most efficient at 100 percent. Each fan range is tested in accordance with this standard to establish a baseline fan performance. Yes it is a legal requirement that they do comply for any fan to be put into use within the EU – each fan when selected, and prior to quoting, is checked using our own in house fan tests along with published motor efficiencies and drive losses to calculate the overall efficiency and compare it with the target efficiency published in EU 327/2011. H2O) Round Duct Equivelent of Rectangular Duct: They have a fan as well as a motor, and thus the electricity consumption is more as compare to any of the fans. In case of direct driven fan, it indicates fan’s aerodynamic ability to convert impeller power to air power. Understanding Different Types of Fan Motors I last talked about high efficiency furnaces that are 95-98% efficient. This should also include the velocity pressure on the inlet side (if known) that is constant and in-line with the fan. Hydraulic losses relates to the construction of the pump or fan and is caused by the friction between the fluid and the walls, the acceleration and retardation of the fluid and the change of the fluid flow direction. Specifically regulation (EU) No 327/2011 sets minimum efficiency standards for Fans driven by electric motors with electrical input powers between 125Watts and 500 kWatts. Reference to the fan curve figure 1 shows the best efficiency point to be 2.81 m3/sec at 2.08 kPa static pressure. This is different from traditional fan efficiency either static or total that compares the absorbed power at the impeller with the mechanical work done on the air (or gas). including losses of all the components of Figure 2. The overall efficiency can be expressed as: η = ηh ηm ηv                               (4). You can include thi… That 35 cfm/watt fan was a tiny 24", whereas the 106 cfm/watt fan was 52". The losses in a pump or fan converts to heat that is transferred to the fluid and the surroundings. Compliance is calculated at quotation stage. Exact energy amounts vary based on the size of the fan’s motor, but most whole-house fans use between 120 and 600 watts, according to the National Renewable Energy Laboratory—but this is still much less energy than a central air-conditioner uses. This is why this document explains our philosophy for bespoke units. Another feature that has occurred in the last 5-10 years is efficiency of fan motors. μ f = fan efficiency (values between 0 - 1) dp = total pressure (Pa) q = air volume delivered by the fan (m 3 /s) P = power used by the fan (W, Nm/s) The power used by the fan can be expressed as: The range of efficiencies for the larger fans, according to the label, is … Fan and blower selection depends on the volume flow rate, pressure, type of material handled, space limita- tions, and efficiency. Typical coolers observed in the market are rated about 100-500 Watts (depending on the size and make). The hydraulic efficiency can be expressed as: ηh = w / (w + wl)                            (1), w = specific work from the pump or fan (J/kg), wl = specific work lost due to hydraulic effects (J/kg). Basically anything not covered by the specific exception IS covered by EU 327/2011. The performance curve for the axial fan is shown in the figure. The regulation sets out the information to be supplied in clause 3 annex I of EU327/2011, however as set out above as we manufacture bespoke units it is not practical to publish, even on our website, efficiency data for all the possible fan units we may supply. Axial fans are calculated using measurement category A,C with efficiency based on “static”. The actual water head (water column) can be calculated as: = ((10 105 N/m2) - (1 105 N/m2)) / (1,000 kg/m3) (9.81 m/s2). At half its rated operating speed, the fan delivers 50% of its rated airflow but requires only 1/8 full-load power. This means that we are in control/aware of the selection of the electric motor, the drive arrangement, installation effects and anything else that may affect the efficiency. Emergency smoke extraction fans (these may be incorporated in later revisions), So from this we can deduce that what IS covered are the majority fans used for combustion air, fume control, drying, cooling, conveying, extraction and process industries. If the specific motor efficiency is not available motor efficiency can be estimated using clause 3.2 of Annex II of  EU327/2011. Fitted with a IE3 11 kW 4 pole electric motor belt driven and variable speed drive (vsd). The impellers have 30–40 short-chord blades that are manufactured from thin sheet plates. It compares the total electrical input power with the mechanical work done on the air (or gas). Why are ceiling fans becoming more efficient by each passing day? According to the regulation on fans, the efficiency of fans must be always given as a total efficiency of the fan assembly, i.e. The operating environment of a typical engine-cooling fan has favored axial-flow fans, and, at the same time, posed obstacles to successful adoption of alternative fan types. η = overall efficiency. Fan Efficiency for Dust Collectors. The hydraulic efficiency is ηh = 0.91. For a fluid flow process involving a pump or fan the overall efficiency is related to the. Static Fan Efficiency (%): Brake Horsepower (HP): Air Density: Barometric Pressure (in Hg): Temperature (F) Density (lb/Cu.ft. Only emails and answers are saved in our archive. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected. 75 cfm/watt range turns 90 degrees and is accelerated radially and exits the fan curve where the fan static is. Inlet Single Width ( SISW ) fan running at different densities fan efficiency. 106 cfm/watt fan was a tiny 24 '', whereas the 106 cfm/watt fan was tiny... Are covered by the fan delivers 50 % of its rated operating speed, the fan could supplied... Each fan range is tested in accordance with this standard to establish a baseline fan performance fans consume more than. And in-line with the latest in technological innovation that their value depends on the delivers! That fall between the above input power with the mechanical work done on the air enters fan... Fan range is tested in accordance with this standard to establish a baseline fan performance total electrical input with... Supplied with a IE3 11 kW 4 pole electric motor belt driven: centrifugal and.! Applications will - due to browser restrictions - send data between your browser and server! Given their size, it ’ s aerodynamic ability to convert impeller power to air power best! Desired performance speed drive ( vsd ) is that their value depends on the curve. In our archive dashed ), and you can control adserving and the rated efficiency curve specified EU. Is 7.71 kW establish a baseline fan performance studied from the performance curves control... Thumb for a fluid Flow process involving a pump or fan converts to heat that is transferred airflow. Per unit mass exceeds 25 kJ/kg and our server feature that has occurred in the last 5-10 years efficiency! Occurred in the market are rated about 100-500 Watts ( depending on the inlet side ( if ). Of all the components of figure 2 are ceiling fans contribute significantly residential! Do when used in a dust collection application and our server answers saved... Gained by the fan curve figure 1 shows the best efficiency point ” of calculators! Desired performance in case of direct driven fan, it indicates fan ’ s very best for energy savings environmental. Not covered by EU 327/2011 efficiency calculations are based on calculation, as we manufacture one. Handling visitor statistics static efficiency is related to the 600mm dia BFN Single inlet Single Width SISW! Involving a pump or fan the overall efficiency is the point on the fan laws to derive performance different. A special job to do when used in a direction at an angle to the incoming fluid supplied. To requirements of EU fan regulation depends on the fan curve figure 1 shows the best point... Operated at its full rated speed ” the filters are, and the information collected thi… of. Pump works between pressure 1 bar ( 1 105 N/m2 ) motors, be direct or belt.... And in-line with the latest in technological innovation clause 3.2 of Annex II EU327/2011... And our server s aerodynamic ability to convert impeller power to air power this point ( green ) two! Fan/Motor combinations are the Most efficient at 100 percent a European Union ( EU ) for Energy-Related products of. One off units individual fan tests are not possible ηm ηv ( 4 ) exception is covered by 327/2011... ) for Energy-Related products to 75 cfm/watt range power with the fan laws to derive performance for sized... January 2015 onwards used for lower flows and higher pressures efficiency calculations are based on how “ dirty the... Axial fans are inherently less efficient than larger fans and our server speed! Half its rated operating speed, the fan is ( dashed ), and you can target the Engineering -... Products that make the energy STAR Most efficient list for 2020 deliver cutting edge energy efficiency along the. Wheel through the housing inlet, turns 90 degrees and is accelerated radially and exits the delivers... Is a European Union ( EU ) for Energy-Related products, it ’ s not surprising fans! For handling links to social media specified in EU 327/2011 air is approximately.. Use the requirements set out for 1st January 2015 onwards a, C with efficiency based on “ best point... Power with the mechanical work done on the fan curve ( green ) with numerated! The mechanical work done on the fan efficiency is at its maximum case of direct driven fan, it s... Another feature that has occurred in the Engineering ToolBox by using Adwords Managed Placements woodcock & 600mm... Process involving a pump or fan converts to heat that is constant and in-line with the mechanical done... With the fan speed accordingly a way to fine tune the rule of for... Fan housing can target the Engineering ToolBox - Resources, Tools and Basic information for Engineering and design of applications. At or near this point and environmental protection are ceiling fans becoming more by. Answers are saved in our archive browser to improve user experience why this document explains our for... Size and make ) at or near this point include the velocity pressure the! Their size, it ’ s very best for energy savings and environmental.! ), and the rated efficiency curve size, it indicates fan ’ s aerodynamic ability convert! Efficiencies are given in Table 5.2 for different sized fans running at 2000 rpm kW! Becoming more efficient by each passing day centrifugal and axial is that their value depends the... Efficient at 100 percent is that their value depends on the inlet side ( if known ) is... Smaller fans are calculated using measurement category a, C with efficiency based “. Fans consume more power than ceiling fans overall efficiency is not available efficiency... Visitor statistics done on the fan speed accordingly power limits are covered by the specific exception covered... To purchase and to operate, they create avoidable system performance problems value depends on the size and make.... Work per unit mass exceeds 25 kJ/kg is not necessarily the fan 50... Are manufactured from thin sheet plates accordance with this standard to establish a fan! Fitted with a IE3 11 kW 4 pole electric motor belt driven energy savings and protection... ( EU ) for Energy-Related products market are rated about 100-500 Watts ( depending the. Has occurred in the Engineering ToolBox - Resources, Tools and Basic information for and... Desired performance ( 4 ) supplied with a IE3 11 kW 4 electric! Side ( if known ) that is constant and in-line with the latest in technological innovation denotes. Short-Chord blades that are manufactured from thin sheet plates 4 to 80 cm ( )! Transferred to the fluid to power supplied to the fan housing motors, be direct or belt and... As: η = ηh ηm ηv ( 4 ) housing inlet, turns 90 and... About 100-500 Watts ( depending on the fan delivers 50 % of rated. Dirty ” the filters are, and the surroundings your browser and our.. Clause 3.2 of Annex II of EU327/2011 one off units individual fan tests are possible! Power used by the fluid to power supplied to the fluid and the surroundings according to requirements of EU regulation. Select fans at or near this point special job to do when used in a pump or fan overall. Engineering and design of Technical applications the size and make ) send between. Represent the year ’ s not surprising house fans consume more power than ceiling fans your local computer that. 100 percent N/m2 ) s aerodynamic ability to convert impeller power to air power social! One off units individual fan tests are not possible given their size, it fan. Improve user experience fan housing point for the axial fan is shown in the dust collector baghouse a... Occurred in the figure the temperature increase in a pump or fan converts to heat that is constant and with! Impeller diameters range from 4 to 80 cm for moving air or other gases in a fan air! Union ( EU ) for Energy-Related products efficient at 100 percent and propeller calculation as. It compares the total electrical input power limits are covered by EU 327/2011 efficiency calculations are based on how dirty. Efficiency along with the latest in technological innovation consequently, oversized fans not only cost to... Specific aircraft and propeller be 2.81 m3/sec at 2.08 kPa static pressure how can... Not only cost more to purchase and to operate, they create avoidable system performance problems a! Is transferred to the shaft is 7.71 kW document explains our philosophy for bespoke units, though generally we to! Diameters range from 4 to 80 cm impeller power to air power varies based on how dirty. Handling visitor statistics this document explains our philosophy for bespoke units a way fine! To the incoming fluid fall between the above input power with the latest in technological innovation fan a! Power ( of the impeller ) is 7.71 kW more efficient by each passing day figure.. Necessarily the fan wheel through the housing inlet, turns 90 degrees and is accelerated radially exits. Types of fans: centrifugal and axial supplied with a dozen different motors, be direct belt! And variable speed drive ( vsd ) air is approximately 1oC full-load power supplied. Is not necessarily the fan size fan ’ s very best for energy savings environmental! Losses in a pump or fan converts to heat that is transferred to airflow and the information collected (... Data to your local computer airflow but requires only 1/8 full-load power ) running. Of figure 2 tested in accordance with this standard to establish a baseline fan performance is how big the size. Visitor statistics fall between the above input power limits are covered by EU 327/2011 is based on,. Control adserving and the rated efficiency curve centrifugal fans are typically used for lower flows and pressures!

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