Analysis of European airtightness, watertightness, and wind pressure test standards for exterior doors and windows

1. Overview

Generally speaking, China GB/T7106-2008 "Classification and Testing of Airtightness, Watertightness and Wind Pressure Resistance of Building Exterior Doors and Windows" Performance Classification and Testing" is a general test method standard and multiple product standards. The old version of the grading index is in the test method standard, but the new version of "Testing Methods for Airtightness, Watertightness and Wind Pressure Resistance of Building Exterior Doors and Windows" cancels the grading, and is graded by each product standard. Relatively speaking, in the old grading indicators, the overall requirements of the national standard are relatively low, and there is a certain gap with foreign standards. With the gradual improvement of domestic product quality, it should gradually be in line with foreign standards. The European standard adopts each test corresponding to a test method standard, a grading and judgment standard, and then summarized by a total product standard. The function of each standard is clear, but the number of standards to be viewed in actual operation is indeed numerous. This article will compare the three different airtight standards of Chinese standard, European standard, and American standard, and analyze the airtightness, watertightness, and wind pressure test standards of external doors and windows in different countries or regions. The corresponding standards of the European standard three-characteristic test are shown in Table 1.

^{Table 1 Corresponding standard of European three-characteristic test}

2. Test requirements

In the European standard, since the three tests are expressed in different standards, the sequence of the tests is not specified, but the wind pressure test includes repeated airtightness, and the moisture of the sample after the water tightness test will affect the airtightness results, so the usual test sequence. It is air tightness, water tightness, and wind pressure resistance (including repeated airtightness tests). Generally, the three tests are completed on a set of test equipment with samples with different installation angles. For example, the water tightness test of skylights may require 2 sets of samples.

The basic composition of the three-property test equipment for doors and windows is as follows①Fan; ②pressure control system; ③flow meters; ④ water flow meters; ⑤differential pressure gauge; ⑥ test box; ⑦displacement test components; ⑧spray device, etc. form. The European standard is mainly based on the internal spray method for experimental design, but the external spray can also be used for testing.

2.1 Airtightness test

The European standard airtightness test first needs to determine the gas leakage of the box (test system). If the leakage of the box is less than 5% of the class limit of the test sample, the leakage of the box can be ignored. However, it is difficult to estimate the leakage of the sample before the test, so the conventional test method is generally used, that is, the additional leakage of the box is tested once, and the total leakage (including the leakage of the box and the sample) is tested once. The leakage of the box should be controlled within 30% of the total leakage. The airtightness test process is as follows

(1) When the leakage of the box is ignored, as shown in Figure 1. First switch the sample on and off, check the function of the sample, add positive pressure 3 times of 660Pa, and then carry out the formal test of positive pressure, the pressure sequence is 50, 100, 150, 200, 250, 300, 450, 600Pa. The negative pressure test sequence is the same as positive pressure +Pa-Pa

^{Figure 1 Airtightness test process without considering box leakage 1}

(2) When considering the leakage of the box, the test process is shown in Figure 2

First test the additional leakage of the box, switch the sample, check the function of the sample, test the box with positive pressure 3 times of 660Pa, and then carry out the formal test of positive pressure, the pressure sequence is 50, 100, 150, 200, 250, 300, 450 Negative pressure test suction is the same as repressure.

^{Figure 2 Airtightness test process considering box leakage 2}

Regarding the additional leakage test, the mark in the EN1026 standard is to test negative pressure. This is considered based on the internal spray test device because the purpose of the additional leakage test is to test the leakage of the box. The sealed sample is on the outside, such as internal spraying, the outdoor side of the sample is facing the box, at this time the negative pressure is sucked into the box, so the additional leakage test adopts negative pressure; such as external spraying, the outdoor side of the sample is facing the box In addition, at this time, the positive pressure is sucked into the box, so the positive pressure is the correct test method for the additional leakage test.

The evaluation of the European standard airtightness test is divided into two indicators: unit seam length and unit area, as shown in Table 2 and Table 3. When using the EN12207 standard, it should be noted that this standard evaluates external windows and indoor windows at the same time, so pay attention to the distinction. The former needs to evaluate the airtight performance up to 600Pa pressure, while the latter only needs to evaluate up to 150Pa.

^{Table 2 Air leakage rate per unit area}

^{Table 3 Air leakage rate per unit seam length}

The airtightness test of exterior windows is divided into 4 levels, from 1 to 4. Of these, level 4 is the most stringent and level 1 is the minimum requirement. Satisfying a certain level not only means that the air permeability meets the requirements under 100Pa but also ensures that each test pressure that does not exceed the maximum test pressure meets the requirements of this level according to the standard calculation formula. Such as level 4, needs to be at 50, 100, 150, 200,250, 300, 450, and 600Pa meet the requirements, and the formula for calculating the flow requirements under other grades is shown in formula (1).

Where: Q is the air permeability (limit value) under the test pressure, m/h; Q1o0 is the air leakage rate under the standard pressure of 100Pa, m/h; p is the test pressure, Pa. There will be one test level per unit area and per unit seam length, while the airtightness level has only one value, so it still needs to be judged. When the two grades are the same, the airtightness grade is also the same. When two grades are adjacent (such as one grade 2 and one grade 3), the airtightness grade shall take the better grade (grade 3 and a half count as two grades that differ by one grade (such as grade 1 and grade 3), the airtightness The median value of the density level (level 2)

When two levels differ by more than one level (only one level 1 and one level 4), no rating will be given. Compared with the evaluation methods of other standards, the European standard airtightness rating is slightly more complicated. For non-combination exterior windows, the first two cases are more common. A good grade when the grades are adjacent is to encourage external windows to have a few openings as possible. However, it should be noted that the latter two cases generally appear in the combined exterior window, some of which are fixed fans and some are open fans, resulting in a larger sample area and a smaller slit length. Although the sealing performance of the opening part is poor, due to the large overall area, the leakage rate per unit area can still achieve good results.fruit. To prevent such products with inferior performance from entering engineering applications, it is required that the leakage rate per unit area and unit seam length differ greatly without rating. For products with separate fixed fans, the European standard is not allowed to test, and a rating of 3 is given. , so the fixed fan product can choose to test the airtightness or directly obtain the grade of 3 (the grade of the indoor window is divided into A, B, C, D). Compared with the European standard, the American standard is not suitable for combined external windows. The overall rating is adopted, and the method of rating each opening type of external window is adopted. This is more beneficial for the user to grasp the actual performance of the product. The Chinese national standard GB/T71062019 is no longer rated for airtight performance. The old version has formulated a looser standard due to the consideration of the technological level of domestic doors and windows. At present, the Wang Yi level of doors and windows on the market can completely adopt higher standards to meet the requirements of European and American standards.

2.2 Water tightness test

The European standard water tightness test method adopts the test method of continuous spraying and gradual pressurization. The spray of the test adopts a row of spray pipes at the top of the sample, and the spray amount and spray angle are fixed. The spray angle setting will vary for products with a top edge. The specific requirements are as follows. The spray angle of the sprinkler head can cover 120°, the water spray volume of the first row is 2L/min, and the water spray volume of the increased sprinkler head is 1L/min. The height of the sprinkler head should not exceed 150mm above the opening slot at the top of the sample, and the distance from the sample surface should be 250mm. The spacing of sprinkler heads should be 400mm. When the height of the sample exceeds 2.5m, a row of sprinkler heads should be added. From 4 hours before the test to the test, the sample should be in an environment with a temperature of 10~30C and humidity of 25%~75%. The test sequence is to pressurize step by step. First 15min without pressure, then every 50Pa pressure test for 5min, until leakage occurs. The European standard water tightness test starts from the O level. Level 0 means no water tightness requirements, level 1 means no leakage for 15 minutes without pressurized spraying, and levels 2 to 9 correspond to pressures of 50, 100, 150, 200, 250, 300, 450, and 600Pa in Figure 3, respectively. When the water tightness of the sample is better than grade 9, it can continue to be pressurized, and the pressure is increased every 150Pa, and the final pressure is directly marked as Exxx. Watertight Changjian Piaoxia Glass and Industrial Glass

^{Figure 3 Water tightness test process 1}

2.3 Wind pressure test

The European standard wind pressure resistance test includes 4 test stages, namely wind pressure deformation resistance, repeated pressurization, repeated air tightness after wind pressure, and ultimate wind pressure test. The details are shown in Table 4.

^{Table 4 Wind pressure resistance grade/Pa 1}

Note: When the wind pressure resistance level exceeds level 5, directly mark p; the pressure is used as the test result.

2.3.1 Wind pressure deformation test

The anti-wind deformation pressure is pi pressure. During the test, the pressure should be raised slowly (100Pa/s) to the specified pressure and kept for the 30s, and the deformation of the stressed rod should be recorded. Then release the pressure to Opa, keep it for the 60s, and record the residual deformation of the stressed rod. Calculate deflection separately

2.3.2 Repeated pressure test against wind pressure

The test pressure of repeated pressure resistance against wind pressure is p2 pressure, p2=0.5p1, repeated pressure is under ±p pressure, reciprocating cycle, a completely positive and negative pressure cycle is one cycle, test 50 cycles, and observe whether the sample has damage. The pressure at p/-p2 should be maintained for 7±3s in each cycle, and the process from p2 to -P2 should also be maintained for 7±3s (that is, the period for each pressure change)

2.3.3 Repeat the airtightness test

The procedure for this test is the same as for the airtightness test. Since the additional airtightness test has been carried out, this item can no longer be carried out here (this item needs to be re-tested when the condition of the text box changes) Repeated airtightness is performed after wind pressure deformation and repeated airtightness tests, the result may be less airtight than the first. It is required here that the repeated airtightness result cannot exceed the required value of the level of the first airtightness result multiplied by 120%, otherwise the judgment will not pass.

2.3.4 Ultimate wind pressure test

The ultimate wind pressure test pressure is p pressure, p3=1.5p1 After the ultimate wind pressure test is completed, it is necessary to check whether the sample is in good condition, whether it can switch normally, and record whether there is damage, falling off, etc.

3. Conclusion

Among the performance requirements of the European standard three-property test, the minimum requirements for airtightness and water tightness are lower than those of the Australian standard and the American standard, but the actual project requirements are specified by the owner. Under the relatively high requirements of building energy efficiency regulations in Europe, most of the performance requirements of actual projects require a higher level, even exceeding the highest level. At the same time, there are certain requirements for the heat transfer coefficient and acoustic performance of the product. Skylight products will also require hardware performance. The European standard EN14351-1, as the main standard for the performance requirements of building exterior doors and windows, specifies in detail the performance requirements that door and window products must meet. The three properties of exterior doors and windows are the basic performance requirements of doors and windows. This article describes these test methods and basic requirements in detail, which can be referenced by technicians who implement testing, door, and window suppliers, and managers of engineering projects in Europe.

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