The document has been developed in consultation with manufacturers and suppliers from the commercial refrigeration industry. It is to be used together with the existing BS EN ISO 23953-2 Refrigerated display cabinets – classification, requirements and testing.
The purpose of this method is to allow for the declaration of energy performance when using retrofit measures for open fronted refrigerated display cabinets as outlined in the ETL Criteria List 2021.
Scope
This document provides the method that should be used to test open fronted refrigerated display cabinets (that are designed to display chilled foodstuffs) with retrofit measures (as listed below 1-5). The result would be required as part of the application process for inclusion in the Energy Technology List which will also be published on the ETL website as an information requirement to declare energy performance. The method presented should be followed in its entirety to ensure the accuracy, repeatability, and reproducibility of the tests.
- Strip curtains that consist of transparent, flexible strips hung adjacent to each other, and fastened at both ends to neighbouring strips, in a manner that allows temporary openings to be made in the curtain for the purpose of removing items from the cabinet.
- Blinds that consist of a flexible fabric mounted on a roller mechanism that enables the blind to be deployed across the display window of the cabinet when the retail outlet is closed or during trading. The blind may also incorporate a motorised control system.
- Transparent sliding doors that consist of doors with a heat reflective coating, mounted in a mechanism (that is designed to be installed in the window of the cabinet) that enables the doors to be opened when items need to be removed from the cabinet.
- Transparent hinged doors that consist of doors with a heat reflective coating, mounted in a mechanism (that is designed to be installed in the window of the cabinet) that enables the doors to be opened when items need to be removed from the cabinet.
- Enhanced air flow management systems designed to optimise the descending air curtain at the front of an open refrigerated display cabinet in order to reduce the infiltration of ambient air. This solution may include, but it is not limited to, modifications or attachments to the shelves of the cabinet.
Test requirements
BS EN ISO 23953-2:2015 is the required standard for cabinets with retrofit measures. Cabinets with retrofit measures as defined in the ETL criteria shall comply with the relevant conditions defined in BS EN ISO 23953-2:2015.
The test requirements below shall be applied to meet the ETL criteria of Retrofit Measures for Open Fronted Refrigerated Display Cabinets.
a) All cabinets with retrofit measures shall be tested in a test room conforming to BS EN ISO 23953-2:2015 in climate class III (25°C, 60% RH).
b) The open fronted refrigerated display cabinet that is used for the test shall already be listed on the ETL with an Energy Efficiency Index[1] (EEI) that is (≤) less than, or equal to, the threshold shown in Table 1.1 for the temperature class M0, M1 or M2 for the particular geometry/configuration of the cabinet.
Table 1.1 Performance thresholds for refrigerated display cabinets selected to be used for testing retrofit measures
| EEI performance thresholds (kWh/day/m²) | |||
| Geometry/configuration[2] | |||
| Horizontal | Vertical | ||
| Temperature Class | M0 | ≤ 6.00 | ≤ 7.50 |
| M1 | ≤ 5.00 | ≤ 6.0 | |
| M2 | ≤ 4.50 | ≤ 5.50 | |
c) The retrofit measures that are being tested shall maintain the product temperature classification as shown in Table 1.2 of the selected ETL-listed cabinet when tested to BS EN ISO 23953-2. It is required that the baseline test (without the retrofit measure) and the retrofit test (with the retrofit measure applied) of the selected cabinet are conducted at the same temperature classification.
Table 1.2 Temperature Classifications for Refrigerated Display Cabinets
| Class | Highest temperature θah of the warmest M-package colder than or equal to (°C) | Lowest temperature θb of the coldest M-package warmer than or equal to (°C) | Lowest temperature θal of the warmest M-package colder than or equal to (°C) |
| M0 | +4 | -1 | - |
| M1 | +5 | -1 | - |
| M2 | +7 | -1 | - |
After stable conditions have been reached (as per section 5.3.2.5 BS EN ISO 23953-2:2015), the test period shall be not less than 24h for the baseline and 24h for the retrofit test on all chilled cabinets.
Changes or adjustments to the setting of the cabinet during the stabilisation or test periods are not allowed. Controller changes between the baseline and retrofit tests are allowed only if the retrofit measure is a permanently applied option (e.g., this excludes blinds).
d) Table 1.3 lists three different test options that are required based on the type of the retrofit measure as defined in the ETL criteria. Each testing of a retrofit measure includes a baseline and a retrofit test.
Table 1.3 Tests applied according to the type of ETL retrofit measures
| Test option | Retrofit measures | Baseline test | Retrofit test | Reference section BS EN ISO 23953-2:2015 |
| 1 | Blinds | 12h lights on, 12h lights off | 12h lights on + blinds up, 12h lights off + blinds down | sec. 5.3.2.5 sec. 5.3.2.6 sec. 5.3.2.7.2 b) |
| 2 | Strip curtains & Enhanced air flow | 12h lights on, 12h lights off | After stabilisation: 12h lights on, 12h lights off | sec. 5.3.2.5 sec. 5.3.2.6 sec. 5.3.2.7.1 b) |
| 3 | Doors (sliding & hinged) | 12h lights on, 12h lights off | After stabilisation: 12h lights on + doors opening sequence, 12h lights off | sec. 5.3.2.5 sec. 5.3.2.6 sec. 5.3.2.7.1 b) sec. 5.3.3.2 (chilled cabinets) |
e) Opening frequency of closed cabinets (as per section 5.3.3.2 BS EN ISO 23953-2:2015)
Each door shall be opened 10 times per hour for a total of 15s. During this opening period, the doors shall be kept open beyond the minimum required opening of 13s for chilled food applications.
Where more than one door pertains to the cabinet under test, the sequence in which the doors and lids are opened shall be staggered, i.e., door 1 at 0 min, door 2 at 3 min, door 1 at 6 min, door 2 at 9 min, etc.
Hinged doors shall be opened beyond an angle of 60° while sliding doors shall be opened beyond 80% of the maximum area which can be opened.
Prior to the start of the 12h period of door opening, each door shall be opened once for 3 min. Where a cabinet is provided with more than one door or lid, each door shall be opened once for 3 min consecutively. Within the test period, the doors shall be opened cyclically for 12h within 24h. The 12h cycle of door opening shall start at the beginning of the test period.
Test report
The test report shall be prepared in accordance with the specification set out in section 6 of the BS EN ISO 23953-2:2015.
Suppliers shall report the model and details of the cabinet on which the testing was conducted as well as the retrofit product’s energy saving [%], derived from TEC/TDA[3] calculations, achieved in accordance with the method and test conditions as outlined in this document. These will then be published on the ETL Product Search website.
[1] The EEI is defined as the ratio of the product’s Total Energy Consumption (TEC) to Total Display Area (TDA).
[2] The geometry/configuration of the cabinet refers to the designation under the classification system in BS EN ISO 23953-1:2015 Annex A.
[3] Section 4.2.6 BS EN ISO 23953-2:2015
TDA shall be calculated according to Annex A BS EN ISO 23953-2:2015.
It is important to note that the TDA may change after the installation of retrofit measures (e.g., doors).