Articles and Research Papers

Title: Revolutionary Method of Saving Energy for Commercial and Industrial Fan Systems.
Presented by Mark Bublitz at the 2017 ACEEE Summer Study for Industrial Energy Efficiency, Denver, Colorado. August 15-18, 2017.

Author: Michael Ivanovich, Mark Bublitz, and Tim Mathson.
File: ACEEE-2017-Paper.pdf
Keywords: Fan Energy Index. FEI. Fan efficiency. Regulations. Codes. Standards.
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 fans 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.

Title: Two New Metrics for Fan System Efficiency: Fan Energy Index and Fan Electrical Power.
Presented by Mark Stevens at Energy Efficiency in Motor Driven Systems (EEMODS'17), Rome, Italy., September 6-8, 2017.

Author: Michael Ivanovich, Mark Stevens, and Michael Wolf
File: EEMODS-2017-Paper.pdf
Keywords: Fan Energy Index. FEI. Fan efficiency. Regulations. Codes. Standards.
Abstract: Two new metrics have been developed by the Air Movement and Control Association (AMCA) International and its member companies to support fan efficiency codes, standards, regulations, and rebate programs. Fan energy index (FEI) and fan electrical power (FEP) are wire-to-air, design-point metrics that emphasize compliant fan selections based on operating points. This drives better fan selections for fan type and size. The alternative metric used in U.S. energy codes, fan efficiency grade (FEG), is based on the peak total fan efficiency and considers the fan without a motor or drive. It was used in codes and standards that set minimum FEG levels. FEI and FEP are metrics that emerged from a U.S. Department of Energy (DOE) rulemaking, which has not been completed. These metrics also are being considered by the State of California in the preliminary stages of its appliance energy efficiency code. AMCA currently is in an advanced stage of publishing a calculation standard that defines FEI and FEP, which, when complete, will be submitted for consideration to ISO for use in its fan efficiency standard. This paper describes FEI and FEP and how these metrics may be used in regulations and rebate programs.

Title: New Efficiency Metric for Fans Enables New Approaches for Efficiency Regulations and Incentives.
Presented by Michael Ivanovich at the 9th International Conference on Energy Efficiency In Domestic Appliances And Lighting (EEDAL), Irvine, California, September 13-15, 2017.

Author: Michael Ivanovich, Mike Wolf, Tom Catania
File: EEDAL-2017-Paper.pdf
Keywords: Fan Energy Index. FEI. Fan efficiency. Regulations. Codes. Standards.
Abstract: Since June 2011, the American fan industry has been embarking on the odyssey of being regulated by the U.S. Department of Energy (DOE) for the first time. Nearly six years after the DOE published its intent to regulate fans, DOE has yet to publish a draft test and energy performance labeling procedure or a draft efficiency standard. It is impossible to state at the time of this papers drafting, what the final rules will look like or when they will be issued.

Title: Comparison of U.S. and European approaches to regulating fan efficiency.
Presented at the CIBSE ASHRAE Technical Symposium, Dublin, Ireland 3-4 April 2014

Category: Air Movement
Author: Michael Ivanovich, Neil Jones
File: Comparison of US and European Fan Efficiency Regulations.pdf
Keywords: Fan Efficiency
Abstract: The United States and European Union began regulating commercial and industrial fan efficiency around the same time in 2007; however, they took very different approaches. The European Union began with product regulations stemming from Ecodesign directives. The U.S. began with adopting fan efficiency requirements into model codes and standards for energy efficiency and green construction published by ASHRAE and the International Code Council (ICC). A U.S. federal regulation began through the U.S. Department of Energy after the ASHRAE and ICC provisions had been initiated. This paper describes and compares the U.S. and European approaches regarding fan efficiency regulation. For the U.S. section, emphasis is placed on the use of model codes and standards such as ASHRAE Standard 90.1 because the U.S. Department of Energy regulation is not expected to become effective until 2020. For the European section, an outline of Commission Regulation (EU) No. 327/2011 is provided.

Investigation of the Impact of Building Entrance Air Curtain on Whole Building Energy Use.

Author: Liangzhu (Leon) Wang, Ph.D.
File: Air Curtain Study.pdf
Abstract: The U.S. was reported to consume 19% of the global energy in 2011, and the building sector (residential, commercial and government buildings) accounted for about 41% of the primary energy usage. The top four end uses of the building sector are space heating (37%), space cooling (10%), water heating (12%), and lighting (9%), which sums up to about 70% of the buildings site energy consumption. For commercial buildings, air infiltrations can be as high as 18% of the total heat loss. Air infiltrations (or air leakages) are often caused by unintentional or accidental introduction of outside air into a building through cracks in the building envelope and/or entrance doors. Infiltrations through door openings become quite significant when the doors are used frequently such as in restaurants, retail stores, supermarkets, offices and hospitals (DOE 2012).

A common energy code solution to reducing energy loss from air infiltration through open doors has been requiring a vestibule rather than having a single door. Currently based on the American Society of Heating, Refrigerating and Air-Conditioning Engineers Standard 90.1 Energy Standard for Buildings Except Low-Rise Residential Buildings (ASHRAE 2010), and the International Energy Conservation Code (IECC), in most cases, vestibules are required in climate zones 3 8. However, vestibules seem not to cater to building owners taste due to the concerns over space and construction cost. A vestibule could cost anywhere from $20,000 to $60,000. In addition, a vestibule becomes ineffective when both entrance doors open simultaneously during heavy traffic periods so as to allow cold outdoor air to penetrate.

Air curtains, which are typically mounted above doorways, separate indoor and outdoor temperatures with a stream of air strategically engineered to strike the floor with a particular velocity and position. The air prevents outdoor air infiltration while also permitting an unobstructed pedestrian entryway. An air curtain for a single sixfoot-wide entrance/exit opening is often less than $6,000 plus installation costs. It also helps to block flying insects, dust, wind, cold/warm, and ambient moisture to achieve a better indoor comfort. Furthermore, building entrances equipped with air curtains are believed to be more energy efficient than the entrances with single doors and with vestibules as well. However, an exhaustive literature search reviewed that no previous studies to quantify the impact of building entrance air curtains on whole building energy usage.

The objective of this study is to decide if air curtains can be considered comparable in energy performance to that of buildings with vestibules where they are required by building energy codes and standards in climate zones 3 8 by means of whole building annual energy simulations and computational fluid dynamics (CFD) modeling of air curtains. For the climate zones 1 and 2, where vestibules are not required by the codes, this study will also quantify the potential energy savings of air curtains compared to the baseline case of the building entrance without air curtain or vestibule.

Analytical Model for Axial Fan Performance Rating

Category: Air Movement
Author: Daniel Khalitov; Rad Ganesh
File: 11p_Khalitov_Ganesh_paper.pdf
Keywords: axial
Abstract: Current requirements of AMCA 211 only allow interpolation on one geometric variable (such as blade pitch, hub to tip ratio, number of blades) for geometrically similar fans, and the results have to be verified by tests. A similar allowance is made for solidity. This standard results in massive testing requirements, especially for axial fans with adjustable pitch blades. The paper investigates methods to reduce the testing requirements where the sizes are not geometrically similar and multiple geometric variables are changed. An analytical model of axial fan performance was developed, validated, and applied towards rating of 3 product lines. The wheel diameter was varied from 12.15 to 78.74 inches, hub ratios from .19 to .56, blade angle from 10 to 40, blade count from 2 to 12, and solidity from .09 to 1.27. None of the various sizes were geometrically similar. Full rating procedure per AMCA 211-05 CRP would require a total of 129 air tests with varying fan size, blade count and hub ratio (903 including blade angle variation). Interpolation on one variable per AMCA 211-05 would save about 50% of laboratory testing. Model application reduced the amount of testing by at least 80% while keeping the rating pressure and power data within AMCA 211 tolerances 90% of the time for solidity below 0.65. The model basically employs aerodynamic principles tested and validated across a multi-variable parameter space. It is the authors’ hope that AMCA will consider this approach as acceptable in its future CRP standards for air performance ratings. It is also the authors’ opinion that AMCA should administer the CRP based on performance ratings furnished by the manufacturer while being open to various innovative methods of obtaining these ratings.

Current Projects of the Air Control Division Committees


Category: Air Control
Author: Dane Carey
File: 08p_DCarey_paper.pdf
Keywords: air control division
Abstract: This paper is an update of the projects and accomplishments several of the committees under the Air Control Division of AMCA have been and currently are working on. These projects have been accomplished in many face to face meetings, phone conferences, and emails. These committee members put aside the considerations and needs of their own company and produce standards and programs that are beneficial for the industry and society as a whole. At the end of the day, as a reward for all of this hard work, they are left with a feeling that they have done something that will be used by our industry and can leave a mark on our world. The items below are only part of the items the committees get involved with. In order to plan and know where your company and the industry are headed, getting involved with these types of committees can assist in your company’s success.

Impeller Fatigue Assessment Using an S-N Approach


Category: Air Movement
Author: Samuel Orr
File: 01p_SOrr_paper-1.pdf
Keywords: S-N, impeller, fatigue
Abstract: This report details the application of an S-N method to predict the fatigue life in welded joints. It illustrates some of the challenges that engineers will find when using Finite Element methods to determine weld fatigue life. A proposal is made for modifications to centrifugal fan fatigue life specifications for large industrial and power plant fans. This proposal includes prediction of weld life using FEA and S-N methods.

Laboratory Methods of Testing Induced Flow Fans for Rating, the Development of AMCA Standard 260-07


Category: Air Movement
Author: Bob Valbracht
File: 05p_BValbracht_paper.pdf
Keywords: induced flow fans, 260
Abstract: AMCA Standard 260-07 Laboratory Methods of Testing Induced Flow Fans for Rating is a newly created standard that establishes a uniform method of test for a category of specialized fans called induced flow fans. This test standard and the associated Certified Ratings Program (CRP) were created to satisfy the needs of professionals involved in the design of laboratory or hazardous exhaust air systems. These professionals required detailed and accurate fan performance data to use in numerical and wind tunnel air quality assessments.

Pressure Against Flowrate - Is the Square Law True?


Category: Air Control
Author: W. T. W. Bill Cory
File: 10p_WTWCory_paper.pdf
Keywords: pressure, flow
Abstract: For many years we have lived with the statement that the system resistance is proportional to the flowrate squared i.e. that it is a quadratic relationship. Whilst this is almost true for small changes in the flow, its shortcomings are beginning to be realized in an era of inverters and other methods of wide ranging speed control. System air velocities are often in the transitional zone, such that the Reynolds Number effects have to be considered. The wider the range of flows, the bigger the observed discrepancies. This paper gives the theoretical reasons for the breakdown of the ‘square law’. It also notes that there is no intrinsic loss coefficient for a given duct fitting.

System Effect of Damper Louver Combinations


Category: Air Control
Author: Bob Van Becelaere
File: 07p_BVanBecelaere_paper.pdf
Keywords: louver, damper, system effect
Abstract: The placement of dampers behind a louver is an everyday occurrence and to my knowledge, there is no comprehensive data established to recommend the location of the damper. This paper will give test results to verify the system effect of dampers placed at various distances from a louver.

The Thrust of ANSI/AMCA 230-07


Category: Air Movement
Author: Richard Aynsley
File: 04p_RAynsley_paper.pdf
Keywords: thrust, ansi, amca 230, circulating, fans
Abstract: The new ANSI/AMCA 230-07 rates air circulating fans by the thrust force they develop. Independent tests indicated that the airflow rate through air circulating fan is not uniquely determined from thrust as suggested in Equation 9.5 of the previous version of the standard. The new standard does include an informative appendix indicating a method for measuring flow rate for a particular region of the air flow.

Treatment of Tonal Sound in the Development of Fan Sound Ratings


Category: Air Movement
Author: Tim Mathson
File: 12p_Mathson_paper.pdf
Keywords: bpf, sound, 301
Abstract: One of the cornerstones of Air Movement and Control Association International (AMCA) is the Certified Ratings Program. This program has helps assure specifiers, engineers, and users that air movement products are tested, rated, and certified in accordance to established testing standards. This program provides the best assurance available that the product will perform as stipulated by the manufacturer. The Certified Ratings Program starts with accurate test standards. For fan sound performance, this standard is AMCA 300, “Reverberant Room Method of Sound Testing for Fans". From the test data, AMCA/ANSI 301, “Methods of Calculating Fan Sound Ratings from Laboratory Test Data”(1), details how the sound data for the tested fan sizes and speeds can be converted to other sizes and speeds. The cost required to test every fan size and speed required by the public would obviously be cost prohibitive and would require enormous investment in large test facilities. Therefore, the conversion to non-tested sizes and speeds is also critical for the Certified Ratings Program. AMCA 301 was first published in 1965. The 1976 revision introduced the Generalized and Specific Sound Power methods as “graphical methods” of predicting sound for non-tested sizes and speeds. Ironically, there was no graph or figure to explain these methods in the standard. Needless to say, revisions to this standard made it easier to understand with visual examples. However, for an engineer just entering the industry, it remains a difficult standard to fully understand. While attempts have been made to simplify the methods into more of a step by step procedure, it still requires considerable experience to really understand the standard and use it effectively. The latest version of AMCA 301 introduced another method of predicting sound called “interpolation”. This addition provided detailed guidelines to a procedure that has commonly been used to obtain sound ratings in between tested fan sizes and speeds. Some changes were also made to the graphical or fan law methods of extrapolating fan sound in the area of the Blade Pass Frequency (BPF).

Vibration Measurement Systems and Guidelines for Centrifugal Fans - A Field Perspective


Category: Air Movement
Author: Bob Shannon
File: 06p_BShannon_paper.pdf
Keywords: vibration
Abstract: This paper presents an overview and discussion on vibration measurement systems, transducer types, advantages and disadvantages, and usage guidelines for centrifugal fan applications. The emphasis is on vibration measurement systems from a field perspective considering transducer types and configurations, vibration transmissibility, and typical diagnostic considerations used to quantify vibration severity and fan mechanical condition.