Description of test procedure for professional kitchen refrigerators and freezers according to EN441

Danish Technological Institute

25 February 2005/Revised 2 February 2006/Per Henrik Pedersen

Summary: This is a technical note that can help technicians specify the test procedure. The note might appear incomprehensible to those who previously have not tested kitchen cabinets. If detailed test conditions are of no interest, this note can be left out.

The objective of this note is to give a popular and readable description of test procedures. The tests shall take place according to EN441, and the descriptions in that specific standard are the ones that are valid.

The tests connected with energy consumption and energy efficiency take place in climate chambers at a certain ambient temperature and humidity ("climate class 4"). The cabinet will be filled with test packages and tested with door openings as described in the standard. The different temperatures and the energy consumption will be registered and a test report will be prepared as specified in the standard.

Test procedure

Professional kitchen refrigerators and freezers are tested according to EN441 "Refrigerated Display Cabinets" although the standard strictly speaking does not cover much more than refrigeration display cabinets. All tests and test methods known to Danish Technological Institute refer to EN441. That test standard is similar to the corresponding standard for domestic refrigerators and freezers (EN153), but there are also differences.

According to EN441, it is possible to choose different climate classes (e.g. climate class 4: 30°C, 55% relative humidity), whereas EN153 has a certain climate test (+25°C, 60% RH) – corresponding to climate class 3 in EN441.

Climate class 4 (30°C, 55% RH)

In Great Britain testing is carried out according to climate class 4 (30°C, 55% RH), as it is believed that climate class 4 gives an improved impression of reality in professional kitchens compared to climate class 3. Therefore, we will in Denmark also take a starting point in climate class 4 which is regarded as fair as kitchen environments often are somewhat warmer than normal room temperature.

Temperature class M1 and L1

EN441 deals with different climate classes as well as with different temperature classes. For instance, temperature class M1 indicates that the highest temperature of the warmest test package during testing always is less than (or equal to) + 5°C and the lowest temperature of the coldest test package is always higher than (or equal to) –1°C.

Temperature class L1 indicates that the warmest package always is below (or equal to) –15°C and the lowest temperature of the warmest test package is less than (or equal to) –18°C.

Other temperature classes also exist, but they will not be mentioned here as that would create unnecessary confusion.

Climate chamber

The energy test takes place in a climate chamber according to the specifications in EN441. That i.a. means that the climate chamber has to be insulated, the floor must be made of concrete, the luminous intensity has to be 600 (+-100) lux, walls and doors have to be painted light grey with an emissivity of between 0.9 and 1.0. There has to be a horizontal air velocity of between 0.1 and 0.2 m/sec. Air temperatures measured at different heights must not deviate more than 2°C from the specified climate temperature and the relative humidity must not vary more than 3 percentage point. For further details please refer to the standard.

Test packages

During testing it is necessary to use test packages and M-packages similar to the packages used to test domestic refrigerators and freezers. Packages with a specified content consisting of water and some artificial substances are in question. The packages are wrapped in clear plastic film. The thermal properties correspond more or less to minced meat and the content looks like marzipan. Different sizes exist: 1 kg, 0.5 kg 0.125 kg. The 1 kg packages more or less have the same shape as a brick (50 * 100 * 200 mm). M-packages have specific locations and the packages are similar to the 0.5 kg test packages (50 * 100 * 100 mm). In addition, a thermocouple is placed in the middle with a wire for data collection.

The test and M-packages are used for all temperature classes. A large amount of work is involved in maintaining and calibrating test and M-packages as the packages tend to lose shape and have to be re-frozen into the right shape after thawing.

Packing plan

EN441 specifies, how the cabinet should be packed with packages. Packing has to take place according to figure 10 in EN441-5 (Closed vertical cabinet).

The figure (Figure 10 in EN441) shows how test packages and M-packages (with crosses) should be packed.

The filling height on the shelves must be half of the free height (with a margin between 0 and 25 mm). The M-packages have to be placed near the edges as shown in the above figure. For further details please refer to EN441 (part 5).

Door openings

Each door or glass lid has to be opened 6 times/hour. If there is more than one door or glass lid, the doors (or lids) have to be opened in shifts. If there e.g. are two doors, door 1 has to be opened at 0 minutes, door 2 at 5 minutes, door 1 is reopened at 10 minutes etc. The doors have to be opened up to an angle of more than 60°. The door has to remain open for 12 seconds, so it is open to air of more than 60° for at least 10 seconds.