In terms of product quality, merchants mainly adopt three methods to pass off inferior goods as good ones: First, using smaller-sized profiles which are originally intended for making doors, windows or indoor partitions. Some dealers use these profiles to seal balconies for consumers, and due to insufficient strength, they are prone to quality problems; Second, using unqualified plastic-steel profiles that may cause deformation, cracking, shedding and discoloration during use; Third, not adding steel lining or using thin iron sheets to impersonate steel lining inside the doors and windows, which cannot guarantee the overall quality of the assembly. In the installation of plastic-steel doors and windows, non-standard operations by construction teams lead to many problems. These issues are mainly caused by negligence during transportation, loading, unloading, and installation. Therefore, installers should handle the materials gently, avoiding prying, throwing, or dropping them. When tapping on door frames, a plastic hammer should be used lightly, and an iron hammer must never be used. Secondly, after the installation of doors and windows, tilting or poor sliding of the door panels can occur, mainly because installers fail to check the verticality with a plumb bob or level, leading to excessive deviation. Therefore, doors and windows must be installed strictly according to installation specifications. If the doors and windows are not level, there may be uneven gaps between the sash and frame, sometimes wider at the top and narrower at the bottom or vice versa. To identify quality differences, observe the appearance color of the plastic-steel doors and windows, which should be bluish-white. Overly white or grayish colors indicate insufficient stabilizing components in the material, which can easily age and turn yellow over time. The surface should be smooth and flat without weld separations or fractures. Door and window frames should have embedded dedicated steel linings. Sealing strips should be even, without curled edges or disengaged grooves, odorless. Hardware should be flexible and smooth; auxiliary materials such as pressure strips and sealing strips for plastic-steel windows and doors should match the main profiles; drainage slots and air pressure balance holes should be processed alternately to prevent direct entry of cold wind and dust. Well-assembled plastic-steel windows often have closed caps on the drainage hole parts to prevent rainwater from entering the room. The selected glass for plastic-steel windows and doors should be flat, free of water ripples, securely installed, and not directly contact the plastic profiles, with sealed pressure strips tightly adhering to the seams. Double-glazed windows should have no dust or moisture inside the cavity. Sliding window frames should have aluminum tracks at the bottom for easy replacement. Generally, double-wheel systems are better than single-wheel ones.
Do not buy plastic-steel windows priced below 200 yuan. Pricing methods are similar to other decoration materials, calculated per square meter including screen window costs. Among the three types of plastic-steel windows—hinged, tilt-and-turn, and sliding—the sliding windows are the cheapest, with small assembly factories charging around 160 yuan per square meter, while imported products can reach up to 600 yuan per square meter. Hinged windows are moderately priced, ranging from 250 to 1000 yuan per square meter; tilt-and-turn windows are the most expensive, ranging from 300 to 1200 yuan per square meter. Additionally, there is a 30-yuan delivery fee and about 50 yuan for dismantling old windows.
The technical content of plastic-steel windows varies greatly. Street vendors with rudimentary processing equipment cannot guarantee the accuracy and strength of the windows. Moreover, the quality of the steel lining inside the profiles is often substandard, or even absent, and other accessories are also inferior. It's reported that if the price of sliding windows is below 200 yuan or hinged windows below 300 yuan, it's very likely fake Hai Luo or Shi De profiles are being used, or cost reduction is achieved through the use of low-quality, inexpensive hardware and steel lining. Consumers should purchase carefully.
Before choosing a brand of plastic-steel doors and windows, consumers can ask the seller for the inspection report of the plastic-steel materials, checking four main indicators: hardness, low-temperature falling weight impact test, dimensional change rate under high and low temperatures, and corner strength test to ensure they meet requirements.
Currently well-known domestic thermal break aluminum profiles include: Feng Aluminum Thermal Break Aluminum, Peace Thermal Break Aluminum, Australian United Thermal Break Aluminum, Beixin Thermal Break Aluminum, Huajian Thermal Break Aluminum, Zhongya Thermal Break Aluminum, and Weiye Thermal Break Aluminum.
Thermal break aluminum, also known as insulated thermal break aluminum, insulated aluminum alloy, or thermal break aluminum alloy, is a type of aluminum-plastic composite window. It has superior performance compared to ordinary aluminum profiles.
The principle of thermal break aluminum-plastic composite windows is to use plastic profiles (with thermal insulation 1250 times higher than aluminum profiles) to separate the indoor and outdoor layers of aluminum, forming a new type of insulating aluminum profile. Windows made from this profile have the same level of thermal insulation as plastic (steel) windows—national standard grade—completely solving the fatal problem of aluminum's rapid heat conduction and its failure to meet energy-saving requirements. Simultaneously, new structural designs address the long-standing issue of "poor sealing in aluminum sliding windows." This product uses aluminum on both sides, with plastic profiles serving as the insulating material in the middle. This innovative design combines the advantages of plastic and aluminum, meeting various requirements for decorative effects, window strength, and durability. Super thermal break aluminum-plastic profiles can achieve a three-seal structure for windows, reasonably separating the vapor chamber, successfully achieving balanced air-water pressure, significantly improving the water-tightness and air-tightness of the windows. The air-tightness of these windows surpasses any aluminum or plastic windows, ensuring no dust on indoor window sills and floors in areas with strong winds and sandstorms. They also ensure residents within 50 meters of highways are not disturbed by noise, with performance comparable to casement windows.
This window integrates the advantages of both aluminum and plastic windows, eliminating their respective disadvantages, becoming an ideal choice for users. Currently sold at around 400-580 yuan per square meter, slightly higher than regular aluminum or plastic sliding windows, but with much better comprehensive usage effects than ordinary aluminum-plastic composite windows, even surpassing double-layer aluminum sliding windows, offering excellent value for money. Spending an extra 30-50 yuan is worth it, considering heating and cooling electricity savings of 50%, with energy savings over three years compensating for the initial investment.
[Editing Section] The biggest characteristics and performance of thermal break aluminum:
The principle of thermal break aluminum alloy is to insert an insulating strip into the aluminum profile to form a thermal break, effectively preventing heat transfer. The thermal conductivity of thermal break aluminum alloy profile windows is reduced by 40-70% compared to non-thermal break aluminum alloy profile windows.
Advantages of thermal break aluminum:
1. Excellent thermal insulation. Using soft combination of inner and outer frames with insulating profiles, the frame adopts a three-seal structure with one rubber strip and dual brushes, providing excellent airtightness, water-tightness, and thermal insulation. The window sash uses a hollow glass structure, showing outstanding soundproofing, thermal insulation, and energy-saving capabilities, with a heat transfer coefficient K value detected at 2.23-2.94 w/2K or lower, significantly saving energy.
2. Water-proof function. Designed with a structured drainage system based on pressure balance principles, featuring sloped step-like designs and drainage outlets for smooth water discharge and excellent water-tightness.
3. Prevents condensation and frosting. Achieves triple-seal structure for windows, effectively separating the vapor chamber, balancing air-water pressure, significantly improving water-tightness and air-tightness, achieving bright and clear window effects.
4. Mosquito-proof and insect-proof screen design. Invisible screens can be installed inside or outside, preventing mosquitoes, flies, especially suitable for northern regions with high mosquito populations.
5. Anti-theft and anti-loosening devices. Equipped with unique multi-point hardware locks, ensuring stability and safety during use.
6. Noise reduction and soundproofing. Carefully designed structure with tight joints, tested results show sound insulation reaching 30-40 dB, ensuring residents within 50 meters of highways are not disturbed by noise, maintaining quiet comfort near busy streets.
7. Fire-resistant function. Aluminum alloy is a metal material, non-combustible.
8. Wind-sand protection and wind-pressure resistance. Inner frames use hollow designs, resisting wind pressure deformation and vibration effectively, suitable for high-rise buildings and residential homes, allowing large window designs with extensive light transmission. The airtightness of these windows surpasses any aluminum or plastic windows, ensuring no dust on indoor window sills and floors in sandy areas.
9. High strength, no deformation, maintenance-free. Thermal break aluminum window bodies exhibit high tensile and shear strength, resisting thermal deformation, durable and long-lasting. Resistant to acid-base erosion, does not yellow or fade, almost maintenance-free.
10. Various colors, highly decorative. Can achieve different colors on indoor and outdoor surfaces of windows, satisfying customer preferences for color effects, spatial aesthetics, and personalized architectural design requirements. Profiles feature streamlined designs, luxurious and elegant.
11. Green building materials, circular economy. Thermal break aluminum windows do not produce harmful substances during production, all materials are recyclable and reusable, classified as green building environmental protection products, consistent with human sustainable development.
12. Multiple opening forms, comfortable and durable. Available in casement, inward tilting, top-hung, sliding, and combined casement/inward tilting styles, suitable for public buildings, residential communities, and municipal projects. High-quality hardware is durable, with ergonomically designed handles for aesthetic comfort and easy operation. Each action is tested, fatigue tests exceed tens of thousands of cycles, sliding effortlessly and silently. Mature and perfected window processing technology, produced with high-precision CNC machining centers, ensuring stable and reliable quality.
New technological features of thermal break aluminum profiles:
⊙ Applying thermal break aluminum profiles, combining inner and outer aluminum and the insulating strip using a rolling process.
⊙ Using double-glazed glass to enhance thermal insulation and soundproofing.
⊙ Adopting independent sealing structures, sliding windows use a dual-rubber strip and dual-brush four-seal structure; casement windows use a hard seal and two soft seals three-seal structure based on equal pressure principles, providing excellent airtightness and water-tightness.
⊙ Selecting premium accessories, aesthetically pleasing, flexible operation, safe and reliable, beneficial for window thermal insulation effects.
Concerns exist regarding the actual use of thermal break aluminum windows in China, with common deceptive practices identified:
One is "beam substitution": replacing the European-standard glass fiber-reinforced polyamide nylon (PA66) insulating strip (nylon 66 insulating strip) commonly used for decades with low-cost general-purpose plastic—polyvinyl chloride (PVC) insulating strips (PVC insulating strips), which are only allowed for non-structural materials by relevant national departments. Due to the significant difference in linear expansion coefficients between PVC and aluminum and its low strength, poor heat resistance, and inadequate aging resistance, the resulting thermal break aluminum profiles can cause loosening or complete detachment of the PVC insulating strip within the aluminum profile due to thermal expansion and contraction, leading to window looseness, deformation, compromised airtightness and water-tightness, or even complete disintegration.
Two is "deceptive tactics": bidding with sample windows using imported nylon 66 insulating strips, then switching to PVC or domestically produced nylon insulating strips during actual processing, or mixing imported nylon 66 with PVC or other insulating strips, positioning the trademarked side outward to "prove" the quality level of the insulating strip. This tactic is highly concealed, identifiable only before processing when both insulating strips are visible.
Three is "muddying the waters": the quality of the insulating strip is foundational but not the sole guarantee of thermal break window quality. Since 2003, domestically produced nylon insulating strips began appearing, reducing costs by partially or fully replacing glass fibers with ordinary mineral materials (commonly referred to as fillers). These strips perform poorly in mechanical strength, heat resistance, and aging resistance compared to glass fiber-reinforced nylon 66 insulating strips. As national standards for insulating strips are still under final approval, domestic nylon insulating strips present related performance test reports derived from injection-molded parts made from nylon mixed with ordinary minerals, which do not represent the performance of finished products after extrusion and cooling processes.
Four is "cutting corners": some thermal break aluminum window enterprises adopt a compromise solution: using low-quality, cheap PVC or domestic nylon insulating strips for window frames fixed to walls, and high-quality imported nylon 66 insulating strips for movable window sashes. They reason that window frames pose little risk even if defective, whereas window sashes, being independently load-bearing, cannot afford quality issues.
In conclusion, before the industry standard for thermal break aluminum windows is issued, concerning phenomena exist in the thermal break aluminum window market, primarily due to insufficient understanding and recognition of the new technology by project owners. We call on industry experts to objectively and scientifically prioritize product quality and consumer responsibility, regulating this disorderly competition as soon as possible. A professional attitude responsible for product quality and people's living standards is fundamental to corporate integrity. Without quality awareness, even established standards would be meaningless, as their purpose is to ensure product quality.
If you want better sealing effects, it is recommended to use thermal break aluminum, which separates indoor and outdoor layers of aluminum while closely connecting them into a whole, forming a new type of insulating aluminum profile. Windows made from this profile have the same thermal insulation level as plastic (steel) windows—national standard grade—completely solving the fatal problem of rapid heat conduction and non-energy-saving properties of aluminum, while addressing the long-standing issue of "poor sealing in aluminum sliding windows." This product uses aluminum on both sides, with plastic profiles serving as the insulating material in the middle. However, the cost of thermal break aluminum is higher.
Method for cleaning plastic-steel windows and doors:
First, rinse with warm water, then wipe with a damp cloth dipped in a little alcohol, making the glass of plastic-steel windows and doors exceptionally bright.
Mix tooth powder in water, use this solution to clean both sides of the plastic-steel window glass, dry it with a cloth afterward, and finally polish it with crumpled newspaper.
Mix a little ammonia water (10:1 ratio), wash the glass, and finally dry it with a cloth and crumpled newspaper.
Use slightly damp old newspapers to wipe. Wipe vertically on one side and horizontally on the other to easily identify missed spots.
Drip a little kerosene on the plastic-steel window glass, or apply powdered chalk or gypsum with water on the glass, let it dry, and then clean it with a clean cloth or cotton, making the glass both clean and bright.
If there is paint or dirt on the plastic-steel window glass, apply some vinegar, let it soak, and then wipe it off with a clean cloth.
If the plastic-steel window glass turns black, use a fine cloth with toothpaste to clean it, restoring its cleanliness.
Prevent condensation: The inner surface temperature of profiles with insulating strips is close to indoor temperature, reducing the possibility of indoor moisture condensing on the profile surface.
Energy-saving: In winter, window frames with insulating strips can reduce heat loss by one-third; in summer, with air conditioning, they can further reduce energy loss.
Environmental protection: Through the application of insulating systems, energy consumption can be reduced, along with environmental radiation from air conditioning and heating.
Health benefits: Human heat exchange with the environment depends on indoor air temperature, air flow speed, and outdoor air temperature. Adjusting indoor temperature via windows ensures it remains no lower than 12～13℃, creating the most comfortable environment.
Noise reduction: Using different thicknesses of hollow glass structures and insulating thermal break aluminum profiles' cavities can effectively reduce sound resonance, preventing sound transmission and lowering noise by more than 30dB.
Color variety: After anodization and powder coating, RAL color series offer over 200 different colored aluminum profiles, producing double-colored windows indoors and outdoors through rolling combination.
For identification of Feng Aluminum thermal break aluminum windows and doors:
First, look for spray codes. Genuine Feng Aluminum thermal break aluminum has spray codes applied by the profile manufacturer, which cannot be removed with hard objects or warm towels, a fact generally understood. However, mere presence of spray codes isn't enough to distinguish genuine Feng Aluminum thermal break aluminum.
Second, examine the central insulating bridge and film. The insulating bridge of Feng Aluminum thermal break aluminum is made of nylon, rough in appearance, and the attached film is thick with a whitish inner side. Fake Feng Aluminum thermal break aluminum uses PVC insulating strips, smooth and shiny, with thin films having a blackish inner side. The quality of this insulating bridge directly affects the lifespan of thermal break aluminum.
Third, only Feng Aluminum thermal break aluminum profiles have white batch materials, while others are metallic aluminum in color. Scraping the black electrostatic spray-coated part on the exterior reveals white underneath for Feng Aluminum thermal break aluminum, unlike other materials whose batch materials are colorless (the natural color of aluminum).
Fourth, during electrostatic spraying, powder coating inevitably leaves dirt at the joints, revealing the original white or metallic aluminum color at these points.
Fifth, proper hardware is crucial for perfect balcony installations. Poor-quality hardware can lead to window sash drooping over time under the weight of the thermal break aluminum sash and hollow glass. Jienlang hardware for casement and top-hung windows is among the best domestically, and the set of hardware for swing doors on balconies includes multi-point hinges, considering potential drooping of balcony doors.
Lastly, remember that different thermal break aluminum profiles have their own spray codes, but quality inspection of the insulating bridge is essential. Poor-quality thermal break aluminum may perform worse than plastic-steel windows, like German Veka plastic-steel which can cost over a thousand yuan per square meter. Poor-quality PVC insulating strips in thermal break aluminum can lead to detachment, so selecting thermal break aluminum requires attention to material quality.