UN R122 Supplement 7 (00 series) · UNECE Regulation No. 122 (ECE R122) — Uniform provisions concerning the approval of vehicles of categories M, N and O with regard to their heating systems.
UN R122 — Supplement 7 to the 00 series of amendments
Supplement 6 → 7
- What changed
- The manufacturer can exceed the Annex 5 temperature limits if it demonstrates during the type approval process that its safety concept covers for higher temperatures. The risk for occupants to get burns must not increase compared to the risk caused by the limit temperatures. In vehicles of categories M2 and M3, this possibility applies only to the driver and to passengers seated in the row adjacent to the driver.
- The definitions of “Heating system” and “Electric heater” now also refer to the perceived temperature of occupants.
- A new item in Annex 1 asks if the surface temperature exceeds the limit values in paragraphs 2.1. to 2.3. of Annex 5.
- Why
- Electric vehicles need separate energy to warm the interior, and the heating systems mainly used make the All Electric Range (AER) reduce sharply.
- Radiation warmers were expected to increase the energy efficiency of electric vehicles. For the best efficiency, they cannot meet the Annex 5 limit temperature for non-metallic materials.
- The expert from OICA explained that industry needed flexibility, since objective pass/fail criteria did not exist for such technology.
Q1What changed8 changes
Higher surface temperatures with a safety concept (Annex 5, para. 2)
Paragraph 2 now requires measuring heating system parts likely to come into contact with any occupant, instead of any driver, during normal road use. No such part may exceed the temperature limits in paragraphs 2.1. to 2.3., with one exception. The manufacturer can exceed these limits if it demonstrates during the type approval process that its safety concept covers for higher temperatures. The higher temperatures must not increase the risk for occupants to get burns, compared to the risk caused by the limit temperatures. Any such demonstration and documentation must be appended to the test report. In vehicles of categories M2 and M3, this possibility applies only to the driver and to passengers seated in the row adjacent to the driver.
Limits for the driver and for passengers (Annex 5, paras. 2.1. to 2.3.)
Paragraph 2.1. now covers parts of the heating system likely to come into contact with the driver of the vehicle during normal road use. It limits their surface temperature to 70°C for uncoated metal or 80°C for other materials. Before this supplement, these limits applied to parts likely to come into contact with any driver. Paragraph 2.1. no longer has the 110 °C limit for parts behind the driver’s seat in the case of overheating. Paragraphs 2.2. and 2.3. now say that the part “is limited to” the value, instead of “no part … shall exceed” it. Their vehicle categories, conditions and values do not change.
Definitions of heating system and electric heater (paras. 6.1.1. and 6.1.5.)
The definitions of “Heating system” (para. 6.1.1.) and “Electric heater” (para. 6.1.5.) add the words “and/or the perceived temperature of occupants”. Before this supplement, the definitions did not refer to the perceived temperature of occupants. Paragraph 6.1.5. also writes “on-board” instead of “onboard”. The rest of the definition of “Electric heater”, including its exclusions, does not change.
New item 11 on surface temperature (Annex 1, Part 2, Appendix 1, Section II)
Section II has a new item 11: “The surface temperature exceeds the limit values mentioned in paragraphs 2.1. to 2.3. of Annex 5: Yes/No”.
Q2Why it changed
- Proposed by
- Expert from the Republic of Korea
- Working party
- GRSG, 125th session (March 2023)
Reasons
Unlike internal combustion engine vehicles, electric vehicles have no heating source. They need separate energy to warm the interior of the vehicle. As a result of the heating systems mainly used, the All Electric Range (AER) reduces sharply.
Sources (3)
“electric vehicles, unlike internal combustion engine vehicles, have a structural problem that requires separate energy consumption to warm the interior of the vehicle since they have no heating source”
“are mainly used as heating systems for electric vehicles. As a result, AER reduces sharply.”
“is also able to prevent the sharp reduction of All Electric Range (AER)”
Some automobile manufacturers and research institutes are researching radiation warmers as a way to increase heating energy efficiency. The expert from the Republic of Korea said that this technology was expected to increase the energy efficiency of electric vehicles. It was also expected to prevent the sharp reduction of the AER.
Sources (2)
“some automobile manufacturers and research institutes around the world are actively researching the application of radiation warmer as the way to increase heating energy efficiency”
“He added that the technology of radiation warmers was expected to increase the energy efficiency of EV and to prevent the sharp reduction of the All Electric Range (AER).”
For the best efficiency, the surface temperature of a radiant warmer must be raised above a certain level. In this way, it is not possible to meet the non-metallic material limit temperature in Annex 5.
Sources (2)
“to achieve the best efficiency, the surface temperature of the device must be raised above a certain level.”
“Therefore, in this way it is not possible to meet the non-metallic material limit temperature mentioned in annex 5 of this UN Regulation.”
The expert from OICA explained that industry needed flexibility and no design restrictions, since objective pass/fail criteria did not exist for such technology.
Source
“He also explained that industry needed flexibility and no design restrictions, since objective pass/fail criteria did not exist for such technology.”
Document trail
- 2023-01ProposalECE/TRANS/WP.29/GRSG/2023/8Proposal by the Republic of Korea
- —Working party adoptsECE/TRANS/WP.29/GRSG/104Session report, para. 24 and Annex IV
- 2023-08Sent to WP.29ECE/TRANS/WP.29/2023/100Text that GRSG sent to WP.29 and AC.1
- 2023-11WP.29 adoptsECE/TRANS/WP.29/1175Adopted at the 191st session (session report, para. 180)
- 2024-06-15In forceC.N.256.2024.TREATIES-XI.B.16.122UN depositary notification
Q3Who is affected
Vehicle manufacturer
- To exceed the Annex 5 limits, demonstrate during the type approval process that your safety concept covers higher temperatures. Show that the burn risk for occupants does not increase compared to the risk caused by the limit temperatures. In M2 and M3 vehicles, use this only for the driver and passengers in the row adjacent to the driver.
Component supplier
- If you supply devices that increase the perceived temperature of occupants, check them against paragraphs 6.1.1. and 6.1.5.
Technical service / Approval authority
- Make sure that any demonstration and documentation for higher temperatures is appended to the test report.
- Be ready for the new item 11 on surface temperature. It asks if the surface temperature exceeds the limit values in paragraphs 2.1. to 2.3. of Annex 5.
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ⓘ This report gives advice only. It is not legal or type-approval advice.