Fan Efficiency Measurement
Fan Energy Index (FEI) & Fan Electrical Power (FEP)

Why A New Fan Efficiency Standard?

The AMCA committee, writing in the fall 2017 issue of AMCA's publication, AMCA in motion, explained that in actual use the energy-efficiency of fans varies significantly depending on how and where a fan is used.

For example the leakiness of the building envelope for a specific structure can significantly affect how a fan performs in that environment - more-so than would be affected the efficiency of some other appliances such as a light bulb that doesn't care much where it is providing illumination.

The committee explains that the very same fan might work very efficiently in some locations and very inefficiently in others.

The intent of the new FEI FEP measurements was and remains to permit the most efficient fan model and type is selected for its specific application by looking at just the FEI rating on the fan label.

Instead of specifying a minimum peak efficiency level for each of the various fan types, FEI establishes a baseline efficiency and resulting baseline power that varies with both airflow and pressure, universally applied to all fan categories. (AMCA 2017)

Definition of Fan Energy Index FEI by Equations

1. FEI = Fan Efficiency / Baseline Fan Efficiency
2. FEI = Baseline Fan Electrical Input Power / Electrical Input Power

The second equation is preferred as the object of fan standards is to reduce wasted energy.

Definition of Fan Electrical Power FEP used to derive FEI

FEP is obtained by

Direct measurement of the fan's electrical power input during rating tests

or

Measuring the fan shaft power and incorporating default values for motors and drives. The default values are defined in AMCA Standard 207 (in process of approval as of Fall 2017)

The FEP rating (in kilowatts or kw) for a specific fan is compared against a baseline or "standard" FEP_std to permit deriving FEI

3. FEI = FEP_std / FEP rating

The AMCA committee anticipates that regulatory and energy standards for fans will express a requirement such as FEI >= 1.0 at design point

Why FEP & FEI Work - How They're Used

The AMCA committee explained that for each type of fan, FEI expresses a baseline efficiency and a resulting baseline power that will vary as both air flow and power vary.

For a fan to be compliant with a standard it simply has to deliver sufficient air flow at a specified or sufficient pressure, at a specific FEI ratio (for example 1.0) as shown in equation 3 above.

Whenever the FEI ration shown in equation 3 is greater than 1.0 the amount of energy saved (over the baseline) will be FEI - 1.0 expressed in percent.

A fan that is rated at FEI 1.1 provides the following energy savings over the baseline requirement:

(FEI 1.1) - (FEI 1.0) = 0.1 Energy Savings i.e. 10% saved over the baseline standard.

The purpose of this rating method is to permit FEI to define a compliant range of operation (for varying air pressure, air flow, and energy used to power the fan) instead of a single number. This approach works as well for multiple speed or variable speed fans too, creating a compliant zone of operation that will be described by the fan manufacturer for each fan model.

Where would fans with an FEI of less than 1.0 be permitted? The committee anticipates that there will be allowable exceptions (that is FEIs <1) for fan systems that use variable air volume (VAV systems) used for material handling or in emergency applications.

The committee explain that code authorities and the U.S. Department of Energy may set minimum FEIs for fan applications (or maximum fan power), but the fan manufacturers (and users) can meet these requirements with their choice of specific fan properties: fan motor, transmission, speed control or other features.

Resources & References for FEI & FEP & Fan Efficiency Standards

• AMCA Fan Regulation Committee, "A New Efficiency Metric for Fans Enables a New Approach for Regulations and Incentives", AMCA in motion, Fall 2017 pp. 2-8. AMCA International, Air Movement and Control Association, AMCA International, 30 W. University Dr., Arlington Heights, IL 60004 USA, Tel: +1 847-394-0150 Email: communications@amca.org Website: www.amca.org
  
  Published by the ASHRAE Journal in behalf of AMCA. AMCA, founded in the U.S. in 1917, is an international association with offices in many other countries.
  Website Excerpt 2017/09/20
  
  Air Movement and Control Association (AMCA) International, a not-for-profit association of the world's manufacturers of fans, louvers, dampers, air curtains, air flow measurement devices, ducts, acoustic attenuators and other air system components. Our association was founded in the United States, but we have expanded to be truly international.
  
  AMCA is now represented in several regions, with 350 member companies in 34 countries. Asia AMCA operates out of Malaysia and European AMCA operates out of Brussels. A Middle East AMCA is in the process of formation, and it will operate out of Dubai.
  
  Since its inception in 1917, our mission was to advance the health, growth and integrity of our industry.
• 2024 Fan-Energy-Index Requirements in U.S. Codes, Standards, and Regulations Update [AMCA web page] -
  Excerpt:
  
  AMCA International staff created a table (Table 1) summarizing FEI provisions in ASHRAE and International Code Council (ICC) model energy codes, California’s Building Energy Efficiency Standards, and U.S. Department of Energy and California appliance/equipment regulations.
  
  A second table (Table 2) provides hyperlinks to sources of the referenced documents,
  
  while a third table (Table 3) lists AMCA International resources, including a link for easily finding AMCA International-certified FEI ratings
  
  With kudos to AMCA we note that at least some of these regulations and standards can be downloaded free such as the PDF listed below - you'll have to log in to the AMCA "store" for your free copy:
  
  AMCA 214-21 - Test Procedure for Calculating Fan Energy Index (FEI) for Commercial and Industrial Fans and Blowers
• 2024 California and DOE regulations for fans [web page] in AMCAA's Winter 2024 newsletter.
  
• ANSI / AHRI Standard 210/240 Performance Rating for Unitary Air-Conditioning & Air-Source Heat Pump Equipment [PDF] (2008), retrieved 2017/09/20, original source: http://www.ahrinet.org/App_Content/ahri/files/standard pdfs/ANSI standard pdfs/ANSI.AHRI Standard 210.240 with Addenda 1 and 2.pdf
  Excerpt:
  
  The purpose of this standard is to establish, for Unitary Air-Conditioners and Air-Source Unitary Heat Pumps: definitions; classifications; test requirements; rating requirements; minimum data requirements for Published Ratings; operating requirements; marking and nameplate data; and conformance conditions.
• ASHRAE Standard 189.1 - 2014, Standard for the Design of High Performance Green Buildings, Available from ASHRAE.org
  Abstract:
  
  Standard 189.1 provides total building sustainability guidance for designing, building, and operating high-performance green buildings.
  
  From site location to energy use to recycling, this standard sets the foundation for green buildings by addressing site sustainability, water use efficiency, energy efficiency, indoor environmental quality (IEQ), and the building's impact on the atmosphere, materials and resources. Standard 189.1 is a compliance option of the International Green Construction Code™ (IgCC).
• Harris, Jeffrey, Matt Brown, John Deakin, Steve Jurovics, Afroz Khan, Ed Wisniewski, James Mapp, Barbara Smith, Melissa Podeszwa, and Alison Thomas. "Energy-efficient purchasing by state and local government: triggering a landslide down the slippery slope to market transformation'." In Proceedings of the 2004 ACEEE Summer Study on Energy Efficiency in Buildings, Asilomar, CA: ECEEE. 2004.
  Abstract:
  
  A growing number of jurisdictions are adopting energy-efficient purchasing policies, often based on ENERGY STAR7 labeled products and the U.S. Department of Energy Federal Energy Management Program (DOE/FEMP) criteria. Potential savings from energy-efficient purchasing are about $1 billion/year for all levels of government; state and local purchasing account for more than 75% of this total.
  
  Together, state and local agencies spend annually about $50-70 billion on energy-related products and $12 billion on energy bills. This scale of buying-power, if effectively harnessed, can help transform the market for energy-efficient products.
  
  This paper reviews state and local purchasing programs around the country, explores the origins of these programs (including how they draw upon federal purchasing and ENERGY STAR), and discusses the strategic role of governmental and institutional buying in market transformation. Aggregating public sector demand sends a powerful market signal to manufacturers and vendors.
• ISO (International Standards Organization). 2010. ISO Standard 12759 Fans—Energy efficiency classification for fans. Geneva, Switzerland: ISO. Available at https://www.iso.org/standard/51665.html
  Abstract:
  
  ISO 12759:2010 specifies requirements for classification of fan efficiency for all fan types driven by motors with an electrical input power range from 0,125 kW to 500 kW. It is applicable to (bare shaft and driven) fans, as well as fans integrated into products. Fans integrated into products are measured as stand-alone fans.
  
  It is not applicable to fans for smoke and emergency smoke extraction; fans for industrial processes; fans for automotive application, trains, planes, etc.; fans for potentially explosive atmospheres; box fans, powered roof ventilators and air curtains or jet fans for use in car parks and tunnel ventilation.
• Michael Ivanovich, "A Revolutionary Method of Saving Energy for Commercial and Industrial Fan Systems " [PDF] AMCA International, (2017), Retrieved 2017/09/20, original source: http://aceee.org/files/proceedings/2017/data/polopoly_fs/1.3687898.1501159073!/fileserver/file/790275/filename/0036_0053_000038.pdf
  Abstract:
  
  Fan energy index (FEI) and fan electrical power (FEP) are design-point metrics that emphasize compliant fan selections and as a result break away from the traditional approach of eliminating product models based on best efficiency points and minimum efficiency thresholds.
  
  Consequently, FEI and FEP address the challenge inherent in and somewhat unique to fans: separating a fan’s energy efficiency capability from the energy efficiency of the fan as applied in a system.
  
  This paper provides background on first-generation fan efficiency metrics and describes FEI and FEP and how these metrics may be used in regulations and rebate programs as second generation fan-efficiency metrics.
• Ivanovich, Michael, and Neil Jones. "A comparison of US and European approaches to regulating fan efficiency." [PDF], retrieved 2017/09/20, original source: https://www.amca.org/resources/documents/Comparison of US and European Fan Efficiency Regulations - CIBSE-Dublin-Ivanovich-Jones.pdf
• Kavanaugh, Steve. "Fan demand and energy - Three Air-Distribution Systems" ASHRAE Journal 42, no. 6 (2000): 47.
  Abstract:
  
  The good news is that chillers, furnaces, compressors, and other HVAC components are becoming increasingly efficient. The bad news is that air system friction losses, high ventilation rates, filter efficiency requirements, part-load air distribution methods, and the lack of space for ductwork can combine to make fan demand and energy the largest components in HVAC systems.
  
  Engineers often are occupied by other critical concerns (ventilation air requirements, installation costs, control compatability, legal liability, etc.) so that fan energy reduction may not be a high priority.
  
  This article is an attempt to place fan power and energy in perspective so engineers can decide what level of attention to devote to mimizing the operating cost of this important HVAC component.
• Kemma, R., R. van den Boom, and M. van Elburg. 2015. “Ecodesign Fan Review, Review study of Commission Regulation, (EU) No 327/2011.” Luxembourg: European Commission.
• Malinowski, John, Bill Finley, Peter Gaydon, and Trinity Persful. "Update on DOE extended product regulations—Pumps, fans & air compressors." In Petroleum and Chemical Industry Technical Conference (PCIC), 2016, pp. 1-11. IEEE, 2016.
• Perez-Lombard, Luis, Jose Ortiz, and Ismael R. Maestre. "The map of energy flow in HVAC systems." Applied Energy 88, no. 12 (2011): 5020-5031.
  Abstract:
  
  Heating, ventilation and air conditioning (HVAC) systems are the most energy consuming building services representing approximately half of the final energy use in the building sector and between one tenth and one fifth of the energy consumption in developed countries.
  
  Despite their significant energy use, there is a lack of a consistent and homogeneous framework to efficiently guide research and energy policies, mainly due to the complexity and variety of HVAC systems but also to insufficient rigour in their energy analysis.
  
  This paper reviews energy related aspects of HVAC systems with the aim of establishing a common ground for the analysis of their energy efficiency. The paper focuses on the map of energy flow to deliver thermal comfort: the HVAC energy chain.
  
  Our approach deals first with thermal comfort as the final service delivered to building occupants. Secondly, conditioned spaces are examined as the systems where useful heat (or coolth) is degraded to provide comfort.
  
  This is followed by the analysis of HVAC systems as complex energy conversion devices where energy carriers are transformed into useful heat and coolth, and finally, the impact of HVAC energy consumption on energy resources is discussed.
• Persful T., Ivanovich M., E. Rogers, and Wickes G. 2016. “Look at the Extended Product Motor Labelling Initiatives for Fans.” Proceedings of the ACEEE Summer Study on Energy Efficiency in Buildings. Washington, DC: ACEEE.
• Also seeReferences or Citations at the end of this article