ANSI AMCA 207-2017 pdf free download.Fan System Efficiency and Fan System Input Power Calculation
1 . Purpose
This standard provides a method to estimate the input power and overall efficiency of an extended fan system. An extended fan system is composed of a fan and an electric motor but may also include a transmission and a motor controller. While direct measurement of fan system performance is preferred, the large number of fan system configurations often makes testing impractical. This standard offers a standardized method to estimate fan system performance by modeling commonly used components. Calculations reported in accordance with this standard offers fan users a tool to compare alternative fan system configurations in a consistent and uniform manner. This document does not provide selection guidance. Users must assure that selected components have sufficient capacity and are configured to produce the desired results.
2. Scope
The scope of this standard includes all electric motor driven fan systems that use a specific combination of components as defined below:
1. Fan airflow performance tested in accordance with ANSI/AMCA Standard 210 [1] ANSI/AMCA Standard 230 [2],ANSI/AMCA Standard 260 [3] or ISO Standard 5801 [4] or rated in accordance with AMCA Publication 211 [5].
2. Polyphase induction motors within the scope of EPCA [6], IEC 60034-30-1 [7], or GB 18613 [8]. Other types of motors are explicitly excluded.
3. Pulse-width modulated variable frequency drives (VFDs).
4. Mechanical power transmissions that use V-belts, synchronous belts, or flexible couplings.
3. Definitions and Symbols
For the purpose of this standard, the definitions, units of measure and symbols in this section apply.
Definitions for fan pressures and efficiencies are found in the standards referenced in Section 2.
3.1 Definitions
3.1.1 Fan system
A fan product that includes all appurtenances, accessories, motors, drives and controllers necessary or applied to the fan.
3.1.2 V-belt power transmission
Drive belts having a substantially trapezoidal cross section that uses sheaves (pulleys) having smooth contact surfaces.
Conventional V-belts have a constant cross section along their length, while notched V-belts (also known as cogged V-belts) have slots running perpendicular to their length. The slots reduce bending resistance and offer improved efficiency over conventional V-belts. This standard does not account for this improved efficiency.
3.1.3 Synchronous belt power transmission
Drive belts having a substantially rectangular cross section that contains teeth that engage corresponding teeth on the sheaves (pulleys) resulting in no-slip power transmission. These belts are sometimes called timing or toothed belts.
4. Fan System Energy Calculations (General)
This section describes the calculations required to estimate the extended fan system input power and extended fan system efficiency. Calculations start with the fan performance and then progress through each fan system component.
4.1 Components
4.1.1 Fan
Fan input power, H i , is the starting point for the system calculation. Fan performance shall be determined in accordance with an accepted performance standard such as ANSI/AMCA Standard 210, ANSI/AMCA Standard 230, ANSI/AMCA Standard 260 or ISO 5801. The fan laws shall be used to determine fan performance at operating conditions other than those tested. For calculation of the fan system input power (W c ), the following performance variables must be available for the desired fan operating point:
4.1.2 Power transmission
The power transmission is a component of the fan system that transfers power from the motor to the fan, most often involving a speed change. The transmission is not present in direct drive configurations where the motor is directly coupled to the fan shaft or impeller.
Advisory note: The VFD and motor models used for this calculation are based on constant V/Hz operation and pure sine wave power. In practice, other control settings are sometimes adopted to improve energy efficiency or to better match VFD output to actual fan operating conditions. This document does not provide selection guidance. Users must assure that selected components have sufficient capacity and are configured to produce the desired results. The purpose here is to provide a consistent calculation procedure for comparing multiple fan systems when actual test data are not available. The output capacity of the VFD must equal or exceed the required input to the motor.
