JC/T 2450-2018 English PDF (JC/T2450-2018)

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JC/T 2450-2018: Glass used in the transparent part of passive building
JC/T 2450-2018
JC
BUILDING INDUSTRY STANDARD
ICS 81.040.10
Q 34
Filing No.. 63771-2018
Glass used in the transparent part of passive building
ISSUED ON. APRIL 30, 2018
IMPLEMENTED ON. SEPTEMBER 01, 2018
Issued by. Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword... 3
1 Scope... 4
2 Normative references... 4
3 Terms and definitions... 4
4 Categories and specifications... 5
5 Materials... 5
6 Requirements... 6
7 Test methods... 7
8 Inspection rules... 7
9 Marking, packaging, transportation, storage... 10
Appendix A (Informative) Introduction to the characteristics and general indicators of
passive building... 11
Appendix B (Informative) Glass specifications, structure, thickness for transparent
parts of passive building... 13
Appendix C (Normative) Warm edge spacers... 18
Appendix D (Normative) Calculation method of thermal conductivity of vacuum glass
supports... 19
Appendix E (Normative) Calculation formula for total solar infrared heat transmittance
gIR... 20
Glass used in the transparent part of passive building
1 Scope
This standard specifies the terms and definitions, classification and specifications,
materials, requirements, test methods, inspection rules, marking, packaging,
transportation, storage of glass used in transparent parts of passive building.
This standard is applicable to insulating glass used in the transparent part of the exterior
enclosure structure for passive building, vacuum composite insulating glass products,
etc.
Note. Please refer to Appendix A for the characteristics and general indicators of passive
building.
2 Normative references
The following documents are essential to the application of this document. For the dated
documents, only the versions with the dates indicated are applicable to this document;
for the undated documents, only the latest version (including all the amendments) is
applicable to this standard.
GB/T 2680 Glass in building - Determination of light transmittance, solar direct
transmittance, total solar energy transmittance, ultraviolet transmittance and related
glazing factors
GB/T 11944 Insulating glass unit
JC/T 1079 Vacuum glazing
JGJ 113 Technical specification for application of architectural glass
JGJ/T 151 Calculation specification for thermal performance of windows, doors and
glass curtain-walls
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
Total solar infrared heat transmittance
In the near-infrared band of the solar spectrum from 780 nm to 2500 nm, the ratio -
- of the sum of the intensity of solar radiation directly transmitted through the glass
and the part of the solar energy absorbed by the glass and transmitted through
secondary heat transfer TO the intensity of incident solar radiation in this
wavelength range, which is expressed by gIR.
3.2
Light to solar gain ratio
The ratio -- of visible light transmittance τv TO total solar energy transmittance g,
expressed in LSG.
3.3
Warm edge spacer
Insulating glass spacers with low thermal conductivity.
4 Categories and specifications
4.1 Categories
Products are divided into single-cavity or multi-cavity insulating glass, vacuum
composite insulating glass, etc., according to their structure.
4.2 Specifications
Please refer to Appendix B for the glass specifications, structure, thickness of the
transparent part of the passive building.
5 Materials
Materials shall comply with the corresponding technical requirements in GB/T 11944
and JC/T 1079.In addition, spacer materials and sealing materials shall also meet the
following requirements.
a) Spacer material requirements. Warm edge spacers shall be used as insulating glass
spacer materials in severely cold, cold, hot summer, cold winter areas. The
thermal conductivity of warm edge spacers shall meet the requirements of
Appendix C;
b) Sealing material requirements.
1) Butyl hot-melt sealant shall be used as the first sealant for the warm edge spacer
insulating glass;
Hot summer and warm winter areas ≤ 1.20 ≥ 0.50 ≤ 0.12 ≤ 0.35 ≥ 1.50
Mild area ≤ 1.50 ≥ 0.55 ≤ 0.15 ≤ 0.40 ≥ 1.40
7 Test methods
7.1 The test methods for appearance quality, dimensional deviation, dew point, initial
gas content, ultraviolet radiation resistance, water vapor sealing durability, gas sealing
durability shall be carried out in accordance with the provisions of GB/T 11944.The
test method for vacuum glass properties that constitute vacuum composite insulating
glass shall be carried out in accordance with the provisions of JC/T 1079.
7.2 The K value of insulating glass is calculated according to JGJ/T 151.The boundary
conditions for calculating the K value of vacuum composite insulating glass are selected
according to JGJ/T 151.The calculation method shall be according to JGJ 113.The
thermal conductivity of the support is calculated according to Appendix D of this
standard.
7.3 The test of glass spectrum and the calculation of visible light transmittance τv are in
accordance with the provisions of GB/T 2680.
7.4 The total solar energy transmittance g is calculated according to JGJ/T 151.
7.5 The total solar infrared heat transmittance gIR is calculated according to Appendix
E of this standard.
7.6 Light to solar gain ratio LSG is the ratio of visible light transmittance τv and total
solar energy transmittance g, that is, LSG = τv/g.
8 Inspection rules
8.1 Inspection classification
8.1.1 Exit-factory inspection
Exit-factory inspection includes appearance quality, dimensional deviation, dew point,
and initial gas content.
8.1.2 Type inspection
Type inspection includes all inspection items required by the technology. Type
inspection shall be carried out under any of the following circumstances.
a) During the production process, if there are major changes in structure, materials,
processes, which may affect product performance;
b) During normal production, periodic inspections shall be carried out regularly or
products will be judged to be unqualified.
8.3.2 Dew point
Take 15 specimens for dew point testing. If all are qualified, the performance will be
deemed qualified.
8.3.3 Resistance to ultraviolet radiation
Take 2 specimens for ultraviolet radiation resistance test. If both specimens are
qualified, the performance is deemed to be qualified.
8.3.4 Water vapor sealing durability
Take 5 specimens for the water vapor sealing durability test. If the moisture
permeability index is all qualified, the performance is deemed to be qualified.
8.3.5 Initial gas content
Take 3 specimens for initial gas content test. If all 3 specimens are qualified, the
performance is deemed to be qualified.
8.3.6 Gas sealing durability
Take 3 specimens for the gas sealing durability test. If all 3 specimens are qualified, the
performance is deemed to be qualified.
8.3.7 Heat transfer coefficient K
Take one specimen and test its heat transfer coefficient K value. If one specimen is
qualified, the performance is deemed to be qualified.
8.3.8 Visible light transmittance τv
Take 3 specimens for the visible light transmittance τv test. If all 3 specimens are
qualified, the performance is deemed to be qualified.
8.3.9 Total solar energy transmittance g
Take 3 specimens for the test of total solar energy transmittance g. If all 3 specimens
are qualified, the performance is deemed to be qua...