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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 8484-2008 Graduation and test method for thermal insulating properties of doors and windows and the following main technical changes have been made with respect to GB/T 8484-2008:
——The term "thermal insulating performance for building doors and windows" is added (see 3.1);
——The terms "total hemispherical emissivity" and "glass door" are deleted (see 3.4 and 3.6 of Edition 2008);
——Graduation of thermal insulating performance is deleted (see Clause 4 of Edition 2008);
——The test principle is modified, and the heat loss at the edges of test piece and filler plate is considered in the calculation of thermal transmittance K (see Clause 4; 5.1 of Edition 2008);
——The test device is modified by adding a deflector in the hot box (see Clause 5; 5.2 of Edition 2008);
——The data processing is modified by adding the thermal transmission capacity at the edge line in the calculation formula (see Clause 7.4; 5.10 of Edition 2008);
——The normative annex "Value of thermal transmittance at the edge line" is added (see Annex C);
——The test method for condensation resistance factor is adjusted to the informative annex [see Annex D; 5.1.2, 5.7.7, 5.8.2, 5.9.2, 5.10.2, and Clause 6 e)2 of Edition 2008).
This standard was proposed by the Ministry of Housing and Urban-Rural Development of the People's Republic of China.
This standard is under the jurisdiction of SAC/TC 448 National Technical Committee on Curtain Walls and Windows of Standardization Administration of China.
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The previous editions of this standard are as follows:
——GB/T 8484-1987, GB/T 8484-2002 and GB/T 8484-2008;
——GB/T 16729-1997.
Test method for thermal insulating performance for building exterior doors and windows
1 Scope
This standard specifies the test principle, test device, test pieces and installation requirements, test and test report of the thermal insulating performance for building exterior doors and windows.
This standard is applicable to the thermal insulating performance test for vertical exterior doors and windows of buildings.
2 Normative references
The following referenced documents are indispensable for the application 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/T 4132 Definitions of terms relating to thermal insulating materials
GB/T 5823 Terminology for building windows and doors
GB/T 10294 Thermal insulation - Determination of steady-state thermal resistance and related properties - Guarded hot plate apparatus
GB/T 13475 Thermal insulation - Determination of steady-state thermal transmission properties - Calibrated and guard hot box
3 Terms and definitions
For the purposes of this document, the terms and definitions specified in GB/T 4132 and GB/T 5823 and the following apply.
3.1
thermal insulating performance for building doors and windows
ability of building exterior doors and windows to prevent thermal transmission from indoor to outdoor, which is characterized by thermal transmittance
3.2
doors and windows thermal transmittance
thermal transmission capacity per unit area in unit time under the condition of steady-state thermal transmission when the air temperature difference between both sides of doors and windows is 1K
Note: It is revised from Definition 2.8.15 in GB/T 4132-2015.
3.3
thermal conductance
ratio of the thermal transmission capacity per unit area through the filler plate of certain thickness to the temperature difference between the two surfaces of the plate under the condition of steady-state thermal transmission
3.4
thermal current coefficient
thermal transmission capacity under the condition of steady-state thermal transmission when the temperature difference between the two surfaces of box wall or test piece frame in the hot box is 1K
4 Test principle
Based on the principle of steady-state thermal transmission, the thermal transmittance of building exterior doors and windows is tested by the calibrated hot box method. The hot box is on one side of the test piece, which simulates the indoor air temperature conditions of heated buildings in winter; the cold box is on the other side, which simulates outdoor air temperature and air flow rate in winter. Under the condition that the gaps of the test piece are sealed and both sides of the test piece are kept under stable air temperature, air flow rate and thermal radiation, measure the calorific value per unit time of the heating device in the hot box, subtract it by the heat loss passing through the hot box wall, the test piece frame, the filler plate and the edges of test piece and filler plate, and then divide the value by the product of the area of the test piece and the air temperature difference between both sides, so as to obtain the thermal transmittance K value of the test piece.
5 Test device
5.1 Composition of test device
The test device mainly consists of five parts: hot box, cold box, test piece frame, filler plate and environmental space, as shown in Figure 1.
Keys:
1——Control system; 8——Filler plate;
2——Humidity control system; 9——Test piece frame;
3——Environmental space; 10——Deflector in cold box;
4——Heating device; 11——Refrigeration device;
5——Hot box; 12——Air conditioning device;
6——Deflector in hot box; 13——Cold box.
7——Test piece;
Figure 1 Composition of test device
5.2 Hot box
5.2.1 The net internal dimensions of hot box should not be less than 2,200mm×2,500mm (width× height), and the depth should not be less than 2,000mm.
5.2.2 The hot box wall shall be made of homogeneous material, of which the thermal resistance shall not be less than 3.5m2·K/W.
5.2.3 The hemispherical emissivity of the deflector in hot box facing the surface of the test piece shall be greater than 0.85, and the deflector shall be located in a plane 150mm~300mm away from the hot-side surface of the test piece frame, and shall be larger than the dimension of the test piece.
5.2.4 At least nine air temperature measuring points shall be uniformly arranged between the hot box deflector and the test piece, and thermal radiation shield is required. At least nine temperature measuring points shall be uniformly arranged on the inner and outer surfaces of each wall of the hot box, and the hemispherical emissivity of the adhesive material on the temperature sensors shall be similar to that of the measured surface. The measurement uncertainty of the temperature sensor shall not be greater than 0.25K.
5.2.5 The hot box shall be heated by a heating device with regulated power supply, and the accuracy grade of the power meter shall not be lower than 0.5.
5.3 Cold box
5.3.1 The net internal dimensions of the cold box shall be the same as the overall dimensions of the test piece frame, and the depth shall be large enough to accommodate the refrigeration device and the deflector.
5.3.2 The inner surface of the cold box shall be made of non-hygroscopic and corrosion-resistant material, and the thermal resistance of the cold box wall shall not be less than 3.5m2·K/W.
5.3.3 The hemispherical emissivity of the deflector in cold box facing the surface of the test piece shall be greater than 0.85, and the deflector shall be located in a plane 150mm~300mm away from the code-side surface of the test piece frame, and shall be larger than the dimension of the test piece.
5.3.4 At least nine air temperature measuring points shall be uniformly arranged between the cold box deflector and the test piece, and thermal radiation shield is required.
5.3.5 Forced convection shall be carried out in the cold box by using the deflector and fan to form a uniform and stable airflow from top to bottom along the surface of the test piece; and the distance from the cold-side surface of test piece shall meet the requirement of GB/T 13475 that the average air velocity in the plane shall be 3.0m/s±0.2m/s.
5.4 Test piece frame
5.4.1 The overall dimensions of the test piece frame shall not be smaller than the internal dimensions of the opening of the hot box.
5.4.2 The thermal resistance of the test piece frame shall not be less than 7.0m2·K/W, and the frame surface shall be made of non-hygroscopic and corrosion-resistant material.
5.4.3 At least six temperature measuring points shall be uniformly arranged on the hot- and cold-side surfaces of the test piece frame respectively.
5.5 Filler plate
5.5.1 The filler plate shall be made of homogeneous material with a thermal conductivity of less than 0.040W/(m·K), and the thermal conductivity shall be determined in accordance with those specified in GB/T 10294.
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5.5.2 At least nine temperature measuring points shall be uniformly arranged on the hot- and cold-side surfaces of the filler plate respectively, and the hemispherical emissivity of the adhesive material on the temperature sensors shall be similar to that of the measured surface.
5.6 Environmental space
5.6.1 The test device shall be placed in a laboratory equipped with air conditioning equipment, the fluctuation of air temperature in the environmental space shall not be greater than 0.5K, and the average temperature difference between the inner and outer surfaces of the hot box wall shall be less than 1.0K.
5.6.2 The envelop enclosure of the laboratory shall have good thermal insulating performance and thermal stability, and the inner surfaces of walls and ceilings shall be insulated, and sunlight shall not be prevented from directly irradiating into the laboratory through windows.
5.6.3 The distance between the outer surface of the hot box wall and the peripheral wall shall not be less than 500mm.
6 Test pieces and installation requirements
6.1 Test pieces
One test piece shall be tested, with an area of not less than 0.8m2. The structure of the test piece shall meet the product design and assembly requirements, and no extra accessories shall be attached and no special assembly process be adopted.
6.2 Installation requirements
The hot-side surface of the test piece shall be flush with that of the filler plate. For the filler plate between test piece and test piece frame, the width shall not be less than 200mm, and the thickness shall not be less than 100mm and thickness of test piece frame, as shown in Figure 2. The open joints of test piece shall be sealed on both sides.
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Test principle
5 Test device
6 Test pieces and installation requirements
7 Test
8 Test report
Annex A (Normative) Calibration of thermal current coefficient
Annex B (Normative) Calculation of weighted average temperature
Annex C (Normative) Value of thermal transmittance at the edge line
Annex D (Informative) Test method for condensation resistance factor
Annex E (Informative) Test methods for thermal transmittance of glass
Annex F (Informative) Test methods for thermal transmittance of door and window frames
