Energy Technology List home
Department for Business, Energy and Industrial Strategy

Commercial Fans

1.1           Scope 

A mechanical fan provides forced fresh air ventilation, blowing, extract and circulation. Fans in the scope of this ETL criteria are individual small-duty fans, that have a rated input power between 125W-30kW, featuring a high efficiency electric motor and variable speed drive.   

The rated input power range applicable, is typically catered to fans suited with potential applications in commercial building settings. These buildings include light commercial/retail, offices, hospitality/leisure/sports, health care and education.  

In other words, the scope only considers fans as individual components which are not integrated into other products or systems.  As a result, this excludes all forms of heavy commercial or industrial fans that are integrated into larger ventilation systems, and otherwise catered for bespoke design.  

Therefore, the following fan types are out of scope: industrial fans, fans within systems or centralised/whole building ventilation units (e.g., air handling units, MVHR, cross flow fans, fan coil units, process fans, propellers and fan blowers) and fans operating in specialised applications (e.g., ATEX fans, fans in explosive and high temperature environments, smoke and fire safety fans). 

1.2           Definitions 

A fan consists of a bladed impeller, and a stator and may have a casing, connected directly to an electric motor.  

A Variable Speed Drive (VSD) is used to control the torque and speed of the motor by regulating the power applied to it.  

Fans are categorised according to their blade type/configuration and the direction in which they blow air:

  • Axial fans blow air in a direction parallel to the fan motor shaft; with a fan flow angle ≤20°. 
  • Centrifugal fans blow air in a direction perpendicular to the fan motor shaft; with a flow angle ≥70°. They can be either forward curved or backward curved. ‘Forward-curved’ means a centrifugal impeller with a fan blade angle ≥1°, ‘backward-curved’ means a centrifugal impeller with a fan blade angle ≤−1°. 
  • Mixed fans blow air in a direction between perpendicular and parallel to the fan motor shaft, with a flow angle >20° and <70°. 

Commercial Fans are available in a range of different designs and efficiencies. The Energy Technology List (ETL) Scheme aims to encourage the purchase of higher efficiency products.

The ETL Scheme covers seven categories of products, according to the fan impeller type and configuration:

  1. Axial fans  
  2. Centrifugal fans (forward curved)  
  3. Centrifugal fans (backward curved) 
  4. Mixed flow fans 

Each of the fan categories above can be configured as either plate fans, enclosure cooling fans and all other configurations of decentralised commercial fans. Alternative eligible fan configurations/categories include[1]:

  1. Roof fans (Axial/Centrifugal/Mixed flow impeller) 
  2. Box fans (Axial/Centrifugal/Mixed flow impeller) 
  3. In-line duct fans (Axial/Centrifugal/Mixed flow impeller) 

To be eligible for inclusion on the ETL, products shall meet the requirements as set out below.    

1.3           Requirements  

1.3.1       Eligibility requirements 

The scope entails fans in the current UK commercial HVAC market only (with 125W - 30kW Rated Motor Input). To be eligible, products shall: 

  • Provide decentralised or ducted mechanical supply and extract ventilation only (e.g., ducted twin fan extract systems, inline duct fans), as opposed to being integrated into a larger ventilation unit/system (i.e., air handling units, heat recovery systems, refrigerant, and cooling systems).  
  • Have a high efficiency motor in compliance with the latest Ecodesign regulation on electric motors and variable speed drives (EU) 2019/1781[2], except where the motor is completely integrated into the product in a manner than means its energy performance cannot be tested independently from the product and that satisfies the requirements for exclusion set out in Article 2(a) of this regulation.
  • Provide effective variable speed via integration of a Variable Speed Drive (VSD) and thus being able to link to occupancy/demand control management systems.  
  • Have an appropriate Conformity Assessment mark.  

1.3.2       Performance requirements 

The minimum fan efficiency (ηmin) as set out in Table 1.1, values as a function of the electric power input Pe (in kW), efficiency grade N per fan type, fan pressure (static, total) and measurement category (A, B, C or D). See section 1.4.2 for fan category definitions and function criteria, in compliance to the methodology of the Review of Regulation 327/2011. 

Eligible products shall meet the performance criteria set out in Table 1.1. 

Table 1.1    Performance requirements for commercial fans[3]

Fan type Measurement category Pressure N
Axial A, C static 0.55 0.75
B, D total 0.69 0.85
Centrifugal forward curved A, C static 0.57 0.65
B, D total 0.61 0.70
Centrifugal backward curved A, C static 0.70 0.80
B, D total 0.73 0.85
Mixed flow A, C static 0.63 0.77
B, D total 0.73 0.85
Axial Roof, Box & In-line Duct Fans A, C static 0.50 -
B, D total 0.62 -
Centrifugal Roof, Box & In-line Duct Fans A, C static 0.63 -
B, D total 0.66 -
Mixed flow Roof, Box & In-line Duct Fans A, C static 0.56 -
B, D total 0.66 -

1.3.3       Information requirements  

Suppliers shall report the following parameters for each model, which will be published on the ETL Product Search: 

  • The IE class of the motor within the fan (except for completely integrated motors)
  • The Minimum Operational Fan Efficiency (static, total)
  • Maximum Fan pressure (static, total)

1.4           Measurement and Calculations 

1.4.1       Measurement standards 

The following standards shall be used to determine product performance: 

  • BS EN ISO 5801:2017 - Methods of testing fans, Part 1: Performance Testing Using Standardized Airways 
  • FprEN 17166:2020. Fans. Procedures and methods to determine the energy efficiency for the electrical input power range of 125 W up to 500 kW 

1.4.2       Test Requirements 

  • (1) Measurement category: Fan test configuration according to the arrangement of standardised test airways; also known as installation category according to EN ISO 5801 and EN ISO 13349. 
  • (2) Measurement category A: Test configuration composed of the fan under test without any inlet or outlet duct fitted, optionally tested with the ancillaries supplied with the fan, i.e., protection grid, inlet bell, etc. (Note 1 to entry: Also known as test configuration category A (see EN ISO 5801:2017, 6.2)). 
  • (3) Measurement category B: Test configuration composed of the fan under test with an outlet duct fitted, simulating ducted conditions, optionally tested with the ancillaries supplied with the fan. (Note 1 to entry: Also known as test configuration category B (see EN ISO 5801:2017, 6.3). 
  • (4) Measurement category C: Test configuration composed of the fan under test with an inlet duct fitted, simulating ducted conditions, optionally tested with the ancillaries supplied with the fan. (Note 1 to entry: Also known as test configuration category C (see EN ISO 5801:2017, 6.4). 
  • (5) Measurement category D: Test configuration composed of the fan under test with an inlet and an outlet duct fitted, simulating ducted conditions, optionally tested with the ancillaries supplied with the fan. (Note 1 to entry: Also known as test configuration category D (see EN ISO 5801:2017, 6.5)). 
  • (6) Measurement category E: Test configuration with free inlet and free outlet without a partition. (Note 1 to entry: Also known as test configuration category E.) 

1.4.3       Rounding   

For the avoidance of doubt, conformity with the Best Efficiency Point threshold will not be achieved by rounding up percentages to a whole number. 

1.5           Verification for ETL Listing  

Any of the following testing routes may be used to demonstrate the conformity of products against the requirements: 

  • In-house testing – Self-tested
  • In-house testing – Self-tested and verified or cross-checked by an independent body 
  • Witnessed testing 
  • Independent testing 
  • Representative testing (see clause 1.5.1 below)      

Further information regarding the first three routes can be found in the ETL Testing Framework.

1.5.1       Representative testing  

Where applications are being made for two or more models that are variants of the same basic design, test data may be submitted for a single ‘representative model’ provided that all variants:  

  • Use the same motor (kW rating), fan impeller type and configuration listed in section 1.2.  

It should be noted that:       

  • If a manufacturer voluntarily removes the representative model from the ETL then other products linked with that representative model may or may not be permitted to remain on the ETL.  
  • If any product submitted under these representative model rules is later found not to meet the performance criteria when independently tested, then all products based on the same representative model will be removed from the ETL. 

1.6           Conformity testing 

Products listed on the ETL may be subject to the scheme’s conformity testing programme in order to ensure listed models continue to meet the ETL requirements.  

1.7           Review  

1.7.1       Indicative review date  

This specification is scheduled to be reviewed during the 2024/25 review cycle. 

1.7.2       Illustrative future direction of the requirements   

The next technical review will consider uplifting the performance thresholds for all fan impeller type/configurations. 


[1] Note that a Roof, Box, or In-Line Duct fan including a casing as defined in FprEN17166 may be configured with an Axial/Centrifugal/Mixed flow impeller, however these appropriate categories have been listed as individual categories due to the differing constructions which lead to specific and differentiated market criteria/assessments of their optimum operational efficiencies.

[2] EUR-Lex - 32019R1781 - EN - EUR-Lex (

[3] The indicated efficiency benchmarks do not consider post-installation and maintenance impacts on fan duty and performance overtime, which can further sustain fan efficiency over time, (e.g., inclusive to regular replacement of fan filters and the support from demand control management).