![](\"https:\/\/ebmpapst-7237.kxcdn.com\/en\/files\/2021\/02\/uwe-sigloch-ebm-papst-300x683.jpg\")
Uwe Sigloch, Director of Product Manage\u00adment at ebm-papst in Mulfingen (Photo | ebm-papst)<\/p><\/div><\/div>\n
In essence, a fan system consists of three main compo\u00adnents: the motor, control elec\u00adtronics, and impeller. The effi\u00adciency of each compo\u00adnent can be described by the respec\u00adtive indi\u00advidual effi\u00adciency level. It is usually spec\u00adi\u00adfied in terms of the optimum oper\u00adating range (i.e. \u03b7max) by the manu\u00adfac\u00adturers of these indi\u00advidual compo\u00adnents. If the fan is assem\u00adbled from the indi\u00advidual compo\u00adnents mentioned, the indi\u00advidual effi\u00adciency levels are normally multi\u00adplied and docu\u00admented. However, this can only be a theo\u00adret\u00adical overall effi\u00adciency that cannot be achieved later in oper\u00ada\u00adtion. Why is that?<\/p>\n
The effi\u00adciency describes the ratio of effort to benefit. In the case of the fan, the benefit is that it moves a volume of air against a resis\u00adtance (pres\u00adsure), i.e. the air perfor\u00admance in watts. This is calcu\u00adlated by multi\u00adplying the air flow (in cubic meters per second) by the pres\u00adsure (in Pascal). The effort is the elec\u00adtrical power consump\u00adtion, also spec\u00adi\u00adfied in watts. The result is always <1, as energy is always lost. Now you have a value for the level of effi\u00adciency, for example \u03b7 = 0.8. This would appear to be an objec\u00adtive value that can be used to compare the effi\u00adciency levels of different fan systems. Unfor\u00adtu\u00adnately, this is not always the case.<\/p>\n
The crucial factor is how \u03b7 came about. The ques\u00adtion must then be: has the effi\u00adciency of the fan system been calcu\u00adlated or measured? There is a theo\u00adret\u00adical optimum effi\u00adciency level, and the effi\u00adciency level resulting from actual oper\u00ada\u00adtion. The optimum \u03b7 is always higher (i.e. better) than the measured value\u200a\u2014\u200asome\u00adtimes by 20 percentage points! That is why many manu\u00adfac\u00adturers prefer to specify the optimum \u03b7.<\/p>\n
Measure the fan system as a complete unit<\/h2>\n
But this is not useful for the appli\u00adca\u00adtion, as it cannot be assumed that all three compo\u00adnents will run at their optimum effi\u00adciency at the desired oper\u00adating point. The devi\u00ada\u00adtions are often consid\u00ader\u00adable. A fan system has a sepa\u00adrate overall level of effi\u00adciency in each oper\u00adating state, which is very diffi\u00adcult to calcu\u00adlate if using the indi\u00advidual effi\u00adciency levels of the compo\u00adnents. It is better to measure the fan system as a complete unit.<\/p>\n
When spec\u00adi\u00adfying the indi\u00advidual effi\u00adciency level of the impeller, there is also the addi\u00adtional partic\u00adu\u00adlarity that, in the calcu\u00adla\u00adtion, often total pres\u00adsure increase is used, i.e. the sum of static and dynamic pres\u00adsure. However, only the static pres\u00adsure is rele\u00advant for a venti\u00adlation system. In this way, \u00ad\u03b7max\u00adim\u00adpeller is often inad\u00admiss\u00adably calcu\u00adlated to appear better than it actu\u00adally is.<\/p>\n
At ebm-papst, we follow the Wire2Air approach. We only state actual, measured effi\u00adciency levels. In any case, we recom\u00admend attaching less impor\u00adtance to the effi\u00adciency level. In prac\u00adtice, it is much more infor\u00adma\u00adtive to compare the expected power consump\u00adtion for a specific air-move\u00adment task.\u2002<\/p>\n","protected":false},"excerpt":{"rendered":"
Anyone wanting to purchase a fan system asks them\u00adselves two ques\u00adtions: 1. Which fan will be up to the task? 2. Which fan will be up to the task with the greatest effi\u00adciency? The second ques\u00adtion is about finding a fan that will provide the best effi\u00adciency (\u03b7). In essence, a fan system consists of [\u2026]<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"wp_typography_post_enhancements_disabled":false,"footnotes":""},"categories":[16,4,9],"tags":[],"class_list":["post-14957","post","type-post","status-publish","format-standard","hentry","category-fans","category-insights","category-refrigeration-ventilation"],"acf":[],"_links":{"self":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/14957","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/comments?post=14957"}],"version-history":[{"count":3,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/14957\/revisions"}],"predecessor-version":[{"id":15689,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/posts\/14957\/revisions\/15689"}],"wp:attachment":[{"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/media?parent=14957"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/categories?post=14957"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mag.ebmpapst.com\/en\/wp-json\/wp\/v2\/tags?post=14957"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}