GB 11555-2025 Technical specification for demisting and defrosting systems of motor vehicles-windshield
Technical specification for demisting and defrosting systems of motor vehicles-windshield
1 Scope
This document specifies the technical requirements for demisting and defrosting systems of motor vehicles-windshield, describes the determination methods of test areas, the test methods of demisting and defrosting systems, and the judgment on the same type.
This document is applicable to the design, manufacture and acceptance of demisting and defrosting systems of the front windshield of Category M1 vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 11562-2014 Motor vehicles forward visibility for drivers - Requirements and measurement methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
defrosting
frost or ice on the outer surface of windshield can be removed through the operation of defrosting system and/or windshield wiper
3.2
defrosting system
system used to remove frost or ice from the outer surface of windshield to restore the field of vision
3.3
defrosted area
area of windshield covered with dry surface and completely melted or partially melted (wet) frost
Note: The frost covering can be removed from the outside with a windshield wiper. The defrosted area does not include the area on the windshield covered by dry frost.
3.4
demisting
mist covering the inner surface of windshield can be removed through the operation of demisting system
3.5
demisting system
system used to remove condensate on the inner surface of windshield to restore the field of vision
3.6
demisted area
area on the inner surface of windshield that restores the field of vision after demisting
3.7
V points
reference points for checking the field of vision, of which the positions passing through the longitudinal vertical plane along the centerline of front outer seat in the passenger compartment
Note: It is related to the R point and the design seat-back angle.
[Source: GB 11562-2014, 3.7, modified]
3.8
R point
reference point specified by the manufacturer for each seat that is related to the structure of vehicle
[Source: GB 11551-2014, 3.7]
4 Determination of test area
4.1 Area A
Area A is the area enclosed by the intersection lines of the four planes extending forward from V points and the outer surface of front windshield (see Figure 1). The positions of V1 and V2 points are determined in accordance with GB 11562-2014, 5.1:
a) The vertical plane passing through V1 and V2 points and on the left side of the X-axis forming a 13° angle with the X-axis;
b) The plane passing through V1 point, which forms a 3° elevation angle with the X-axis and is parallel to the Y-axis;
c) The plane passing through V2 point, which forms a 1° elevation angle with the X-axis and is parallel to the Y-axis;
d) The vertical plane passing through V1 and V2 points, which forms a 20° angle with the X-axis to the right of the X-axis.
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Determination of test area
5 Technical requirements
6 Test methods
7 Judgment on the same type
8 Implementation of this standard
Bibliography
GB 11555-2025 Technical specification for demisting and defrosting systems of motor vehicles-windshield
Technical specification for demisting and defrosting systems of motor vehicles-windshield
1 Scope
This document specifies the technical requirements for demisting and defrosting systems of motor vehicles-windshield, describes the determination methods of test areas, the test methods of demisting and defrosting systems, and the judgment on the same type.
This document is applicable to the design, manufacture and acceptance of demisting and defrosting systems of the front windshield of Category M1 vehicles.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 11562-2014 Motor vehicles forward visibility for drivers - Requirements and measurement methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
defrosting
frost or ice on the outer surface of windshield can be removed through the operation of defrosting system and/or windshield wiper
3.2
defrosting system
system used to remove frost or ice from the outer surface of windshield to restore the field of vision
3.3
defrosted area
area of windshield covered with dry surface and completely melted or partially melted (wet) frost
Note: The frost covering can be removed from the outside with a windshield wiper. The defrosted area does not include the area on the windshield covered by dry frost.
3.4
demisting
mist covering the inner surface of windshield can be removed through the operation of demisting system
3.5
demisting system
system used to remove condensate on the inner surface of windshield to restore the field of vision
3.6
demisted area
area on the inner surface of windshield that restores the field of vision after demisting
3.7
V points
reference points for checking the field of vision, of which the positions passing through the longitudinal vertical plane along the centerline of front outer seat in the passenger compartment
Note: It is related to the R point and the design seat-back angle.
[Source: GB 11562-2014, 3.7, modified]
3.8
R point
reference point specified by the manufacturer for each seat that is related to the structure of vehicle
[Source: GB 11551-2014, 3.7]
4 Determination of test area
4.1 Area A
Area A is the area enclosed by the intersection lines of the four planes extending forward from V points and the outer surface of front windshield (see Figure 1). The positions of V1 and V2 points are determined in accordance with GB 11562-2014, 5.1:
a) The vertical plane passing through V1 and V2 points and on the left side of the X-axis forming a 13° angle with the X-axis;
b) The plane passing through V1 point, which forms a 3° elevation angle with the X-axis and is parallel to the Y-axis;
c) The plane passing through V2 point, which forms a 1° elevation angle with the X-axis and is parallel to the Y-axis;
d) The vertical plane passing through V1 and V2 points, which forms a 20° angle with the X-axis to the right of the X-axis.
Contents of GB 11555-2025
Foreword I
1 Scope
2 Normative references
3 Terms and definitions
4 Determination of test area
5 Technical requirements
6 Test methods
7 Judgment on the same type
8 Implementation of this standard
Bibliography
