What software can be used to calculate the heat transfer coefficient of exterior windows?

According to the latest version of the "Code for Thermal Calculation of Building Doors, Windows and Curtain Walls" JGJ T 151-2008 in Section 4 "Thermal Calculation of Glass Curtain Wall", it can be calculated by using special application software, which is much more convenient and can be tried Very pleasantly surprised.

It is all thermal simulation software, and the actual processing technology has a lot to do with it.

Approximate data can be obtained by simple calculations:

First of all, judge the proportion of the frame glass of the door and window (the ratio of the frame area to the glass area), the general insulation material of the frame material is about 15mm wide thermal insulation material, the thermal insulation effect of the thermal insulation strip increases by 5mm, the thermal insulation strip width of the thermal insulation material is 25mm wide, the thermal insulation coefficient of the profile is about or so, the average of 5+12+5 insulating glass is about or so, the thermal insulation coefficient of low-e is about and so, if the frame of the door and window accounts for 30% of the whole window, the glass area accounts for 70%, Then the thermal insulation coefficient of the whole window can be weighted and averaged according to the above data.

Thermal insulation strip 15mm wide insulation material + 5 + 12 + 5 insulating glass = thermal insulation strip 25mm wide insulation material + 5 + 12 + 5 low emissivity low-e insulating glass = this method ignores the coefficient caused by gaps and processing errors!

The principle is provided on the first floor, but the landlord wants the software more.

The user only needs to import the cross-section vector drawing, indicate the material of each piece or directly fill in the thermal conductivity (i.e. thermal conductivity) of each part, for example, pure aluminum at room temperature 237 W m K (aluminum alloy is a little lower), steel about 60 W m K, PA66 GF25 thermal insulation strip, polyurethane composite W M K. After generating a standard-size window model, the software automatically calculates the heat transfer coefficient.

The software includes: Window of Lawrence Berkeley National Laboratory in the United States, the calculation method conforms to the ISO 15099 standard; The MQMC of the Institute of Building Energy Efficiency, Guangdong Academy of Building Research, complies with the JGJ T 151-2008 standard.

According to the latest version of the "Thermal Calculation Regulations for Building Doors, Windows and Curtain Walls" JGJ T 151-2008, Section 4 "Thermal Calculation of Doors and Windows", use professional thermal software to calculate, you can compare the impact of various configurations of doors and windows on the thermal performance of doors and windows, and then compare the configuration and performance of doors and windows of each configuration.

Heat transfer coefficient of the whole window Profile series Heat transfer coefficient of heat insulation strip profile Glass configuration Glass heat transfer coefficient k = series

k = series 20mm

k = series 20mm

k = series 20mm

k=series k=series (filling foam) 5low-e+15ar+5k=filling foam).

k = filling foam).

1.The k-value of doors and windows with full-body aluminum is above 3.

2.The k-value of the doors and windows of broken bridge aluminum is above.

The K value of plastic steel is about the same as that of broken bridge aluminum, and the cost is lower than that of broken bridge aluminum.

3.The k-value of solid wood doors and windows is about the same as the second type.

4. Steel windows are similar to full-body aluminum.

There are several commonly used doors and windows, but the heat transfer coefficient is very different.

In addition, different regions have different requirements for building energy efficiency. Different buildings will also have different insulation requirements.

Simplified calculation method of heat transfer coefficient (k-value) of building exterior windows:

k=q1/√q2

where Q1 is the temperature outside the window, and Q2 is the temperature inside the window.

What does the k in the unit "w m2k" of the heat transfer coefficient k value in the building code mean, for example: January 2000 is just a difference in the starting point of the calculation of the two. Fourth, in addition, there is a parameter very similar to it, that is, heat conduction.

Xingxing Xingxing wrote: Please ask back to consider the average heat transfer coefficient of the exterior wall after considering the thermal bridge, shouldn't it be changed to socks which is generally like this, but the premise is that the K value of the thermal bridge structure should be large, and if the K value of the thermal bridge structure is selected by the user itself, then the final average heat transfer coefficient is naturally small.

Chocolate Everyday wrote: The design of the window structure in the engineering structure is not related to the shading coefficient. In the screen menu, settings - engineering parameters are virtual, in the fourth panel, the last item is "external window shading coefficient", where you can set the shading coefficient of all external windows uniformly (although the software has a default value, but the user can change it arbitrarily), if the shading coefficient of some external windows is different, you can use the envelope structure - change window command to adjust partially or one by one.

Duo Xie replied, but I don't mean that, I mean, whether to build a database, the shading coefficient to be set can be obtained through the selection of materials, or calculated after the combination of materials.

Does the new version take this feature into account? In addition, please ask, can the shading coefficient of the glass ** be checked? Is there an electronic version available?

1. Heat transfer coefficient of all whole windows Profile series Heat transfer coefficient of heat insulation strip profile Glass configuration Glass heat transfer coefficient k = series

k = series 20mm

k = series 20mm

k = series 20mm

k=series k=series (filling foam) 5low-e+15ar+5k=filling foam).

k = filling foam).

According to the latest version of the "Thermal Calculation Regulations for Building Doors, Windows and Curtain Walls" JGJ T 151-2008, Section 4 "Thermal Calculation of Glass Curtain Wall", with software calculation, you can compare the configuration and thermal performance of various commonly used doors and windows, and then compare the cost and cost performance of each configuration of doors and windows.

1. Total heat transfer coefficient: In the past, it was called total heat transfer coefficient. The current national standards and specifications are uniformly named as heat transfer coefficient.

The heat transfer coefficient k value refers to the heat transferred through 1 square meter area within 1 degree (k, ) 1s of the air temperature difference on both sides of the envelope under the condition of stable heat transfer, and the unit is watts (square meters · degree) (w (·k), where k can be replaced). The heat transfer coefficient is not only related to the material, but also to the specific process. Average heat transfer coefficient of the exterior wall:

The average heat transfer coefficient of the exterior wall, including the main part and the surrounding thermal bridges (structural columns, ring beams, and the part of the floor that extends into the exterior wall, etc.). It is calculated by the weighted average of the area of each part of the exterior wall (excluding doors and windows) by the heat transfer coefficient of its area.

What kind of glass is used now?

If the single-layer glass is not good, change the coated glass, then the insulating glass, and then the insulating coated lowe glass.

The standard limit of the heat transfer coefficient of the exterior window complex is the upper limit specified in the energy-saving design standard for the construction building. It is related to the climatic zone to which the project is located (e.g., in a hot summer and cold winter area or in a severe cold area, etc.), the type of the project (e.g., whether it is a public building or a residential building), the orientation of the exterior windows, and the ratio of the window-to-wall area in the direction where it is facing.

The design value of the heat transfer coefficient of the exterior window is the heat transfer coefficient of the exterior window used in the engineering design. It is related to the frame material used in the window (such as ordinary aluminum alloy or insulated aluminum alloy, etc.), the type of glass (such as whether it is insulating glass) and specifications, the gas in the cavity of insulating glass (air A or argon argon), the thickness of the cavity and the number of cavities (such as three glass and two cavities of insulating glass with two cavities).

In principle, the design value of the heat transfer coefficient of the exterior window is required to be no greater than the code limit in the energy-saving design of the building. When the design value of the heat transfer coefficient of the exterior window exceeds the requirements of its code limit, and the main energy-saving index of the external maintenance structure of the design building can meet some basic conditions specified in the standard, a comprehensive judgment can be made on the design building, and the comprehensive judgment shall prevail.

Hope it helps.

The classification of the heat transfer coefficient of glass doors and windows needs to be based on the latest version of the "Thermal Calculation Regulations for Building Doors, Windows and Curtain Walls" JGJ T 151-2008 in Section 4 "Thermal Calculation of Aluminum Alloy Doors and Windows", and use professional door and window thermal software to calculate, you can compare the impact of various door and window configurations on the thermal performance of curtain walls, and then compare the cost of various configurations of doors and windows, you can compare the grading standards of the entire doors and windows!

1.The thermal insulation performance of doors and windows is subject to the heat transfer coefficient {w (k)}, which is the ability to block indoor long-wave radiant heat, and the thermal insulation of doors and windows in winter should be good; The thermal insulation performance of doors and windows is based on the shading coefficient, which is the ability to block outdoor short-wave radiant heat, and the thermal insulation performance of doors and windows should be good in summer. Doors and windows generally account for 20% of the wall, the heat dissipation is 5 or 6 times that of the wall, and more than 40% of the total heat loss of the building.

2.The heat dissipation channels of doors and windows are glass, profile frames, and gaps. The heat transfer coefficient of ordinary insulating glass is k, if you want to further improve the thermal insulation performance of doors and windows, it is very important to improve the thermal insulation level of glass, the heat transfer coefficient of the three-glass double insulating glass and low-e insulating glass we designed is k and k respectively, but the thermal insulation performance of the three-glass double insulating glass is poor, and it can not effectively suppress heat radiation.

Low-E glass is coated with a colorless metal film on the inside of the glass, so that the thermal radiation of the insulating glass is greatly reduced. The insulation and economy of the 12mm insulating layer of insulating glass are the best, and the thermal insulation effect of the 16mm insulating layer is better than that of 12mm, but it is not much improved, and the amount of consumables increases greatly.