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

Automated Permanent Refrigerant Leak Detection Systems

1.1    Scope

Automated permanent refrigerant leak detection systems are products that are specifically designed to continuously monitor the atmosphere in the vicinity of refrigeration equipment and, in the event of detection of refrigerant, give an alarm.

1.2    Definitions

An automated permanent refrigerant leak detection system continuously monitors the atmosphere in the vicinity of refrigeration equipment, and other components or pipework that contain refrigerant. The detection system shall be permanently fixed in place at the site of the refrigeration equipment.

Detection systems may be standalone/fixed point or aspirated systems. Where standalone/fixed point systems have a sensor for each space, aspirated systems have a single master control panel which senses refrigerant concentration levels from multiple spaces by extracting air samples from each space through tubing. 

The Energy Technology List (ETL) Scheme aims to encourage the purchase of products that give an early warning of refrigerant leaks, to allow their early repair, and thus improve the energy efficiency of the refrigeration system and reduce carbon emissions. 

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

To be eligible, products shall: 

  • Continuously monitor the refrigeration system for refrigerant leakage. 
  • Detect the presence of one or more refrigerants (which shall be clearly named in the information supporting the application) and raise an audible alarm when a pre-set level of refrigerant is reached. 
  • Have fittings to allow permanent fixing to the wall or floor. 
  • Standalone systems shall be able to operate in conditions of between --25 to 50°C and relative humidity levels of up to 90%. 
  • Aspirated systems shall be capable of extracting air samples in conditions of between -25 to 50°C and relative humidity levels of up to 90%. The control panels of these systems shall be able to operate in conditions of between 0 to 50°C and relative humidity levels of up to 90%.
  • Have an appropriate Conformity Assessment mark.

Automated permanent refrigerant leak detectors shall be calibrated for each refrigerant named in the application. The product shall be capable of detecting at least one of the following types of refrigerant: HCFC, HFC, HC, HFO, Carbon Dioxide (CO2) or Ammonia (NH3). 

Automated permanent leak detection systems dedicated to ammonia detection for concentration levels at which ammonia is flammable, are not eligible.

1.3.2    Performance requirements

To be eligible, products shall: 

  • Meet the relevant alarm signal threshold set out in Table 1.1 below, which varies with refrigerant type. 
  • Generate an alarm signal when the level of refrigerant in the atmosphere exceeds the alarm signal threshold, which may be equal to or lower than the refrigerant-specific thresholds set out in Table 1.1 below.
  • Have a measurement accuracy and measurement sensitivity according to the refrigerant type, equal to or better than the levels set out in Table 1.1 at refrigerant concentrations up to the relevant alarm threshold in Table 1.1. 

Table 1.1    Performance thresholds for automated permanent refrigerant leak detection systems 

 Refrigerant Alarm signal threshold (parts per million, ppm) Measurement accuracy (ppm) Measurement sensitivity (ppm)
HCFC, HFC, HFO or HC ≤100 ±20 10
CO2 ≤5,000 ±500 100
NH3 ≤100 ±20 10


"≤" means "less than or equal to" where products that can generate an alarm signal at lower refrigerant concentration levels than stated in the above Table 1.1, exceed the performance requirements. 


  • Measurement accuracy refers to the allowed variation between the measured and actual refrigerant level in the atmosphere.
  • Measurement sensitivity refers to the change in the refrigerant concentration level that a product is able to detect. This is not the minimum refrigerant concentration level that the product is able to detect.

1.4    Measurement and Calculations

1.4.1    Measurement standards

The test procedures set out in the following test standards can be used to demonstrate product performance: 

  • BS EN 14624:2005 “Performances of mobile leak detectors and of room controllers of halogenated refrigerants”. (Section 11.2 – Efficiency tests of room controller). 
  • BS EN 14624:2012 “Performance of portable leak detectors and of room monitors for halogenated refrigerants”. 
  • Gas Detector Selection and Calibration Guide, SIRA, 2005, ISBN 10: 1856092976 ISBN 13: 9781856092975.

1.4.2    Test Requirements

The performance of the equipment shall be tested at the concentrations stated in the performance criteria using calibration gases produced using methods that are traceable to British standards. 
A calibration report shall be supplied that demonstrates the product’s sensitivity, accuracy and alarm setting using test gases. 

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-certified
  • 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)

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 products that are constructed using a common set of sensors and electronic modules, then test data may be submitted for a representative selection of models that clearly demonstrate the performance of each type of sensor with each refrigerant, and impact on performance of using different electronic modules. 

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 for review during the 2022/23 review cycle.

1.7.2    Illustrative future direction of the requirements  

A provisional update to the standard for measuring refrigerant concentration levels, prEN 14624:2018 for portable leak detectors has been released. It is currently under review and has not been referenced in this specification; however, future requirements will reference it. There is also a provisional standard prEN 50676 for electrical equipment used for refrigerant and SF6 detection and concentration measurement, which will be referenced in future requirements.