In the vast market of the United States, the demand for high-quality, energy-efficient building materials is ever-increasing. Among these, aluminum windows and doors have gained significant popularity. However, in some areas, meeting certain certifications is crucial, and one such important certification is the NFRC.

The Significance of NFRC Certification

Many local building codes across the United States mandate that windows be NFRC-certified. The National Fenestration Rating Council, abbreviated as NFRC, plays a pivotal role in ensuring that windows, doors, skylights, and accessory products meet strict energy efficiency standards. It provides a unified and independent rating label system that manages the energy consumption performance of these products. This system is highly regarded as it offers fair, accurate, and reliable energy consumption performance ratings.

The NFRC conducts a series of comprehensive test items to evaluate the performance of windows. These include the U value, solar heat gain coefficient, visible light transmittance, air leakage, and condensation resistance. Each of these factors is vital in determining the overall energy efficiency and comfort of a building.

U-Factor

The U-Factor, represented by the orange area, indicates the U value of doors and windows. This value essentially represents the insulation value. It typically ranges from 0.20 - 1.20, and the lower this value is, the better the insulation performance. A lower U value means that the window is more effective at preventing heat transfer, whether it is keeping the heat in during cold winters or blocking it out during hot summers. For example, in regions with extreme cold climates, such as parts of Alaska, a window with a very low U value is essential to reduce heating costs. On the other hand, in warmer southern states like Florida, a low U value helps in minimizing the amount of external heat that enters the building, thus reducing the load on air conditioning systems.

Visible Transmittance

Visible Transmittance, which measures the amount of visible light that can pass through the window, ranges from 0 - 1. In this case, the higher the value, the better. A high visible light transmittance allows for more natural light to enter the interior of a building. This not only brightens up the rooms but also has a positive impact on the occupants' well-being. Natural light has been shown to improve mood, enhance productivity, and even have health benefits. In office buildings, for instance, large windows with high visible light transmittance can create a more pleasant and productive working environment. In residential homes, it can make living spaces feel more open and inviting.

Solar Heat Gain Coefficient

The Solar Heat Gain Coefficient measures the parameter that determines how much the indoor temperature increases due to sunlight. It ranges from 0 - 1, and a lower value is more desirable. In areas with intense sunlight, such as the southwestern states of the US like Arizona, a window with a low solar heat gain coefficient is crucial. It helps in reducing the amount of solar heat that enters the building, preventing overheating of the interior. This is especially important for buildings that rely on air conditioning for cooling. By minimizing solar heat gain, the energy consumption of cooling systems can be significantly reduced.

Air Leakage

Air Leakage measures the amount of air that enters a room. The typical range is 0.1 - 0.3, and as with the other parameters, the lower the value, the better. Air leakage can lead to a significant loss of energy. In winter, warm air can escape through leaky windows, while in summer, cool air can seep out. This forces the heating or cooling systems to work harder to maintain a comfortable indoor temperature. In older buildings, air leakage through windows is a common problem that can be addressed by installing new, energy-efficient windows with low air leakage rates.

Our NFRC-Certified Aluminum Window Series

We are proud to offer two main series of aluminum windows in the USA that are NFRC-certified: the 80 series and the 125 series.

80 Series

The 80 series of our aluminum windows features specific glass specifications. It consists of 6mm low-E glass + 12Ar + 6mm low-E glass + 12Ar + 6mm clear glass. Here, "Ar" stands for argon. The use of low-E (low emissivity) glass helps in reducing the amount of infrared and ultraviolet light that passes through the window while still allowing visible light to enter. The argon gas between the glass panes acts as an additional insulating layer. Argon is a denser gas than air, which reduces heat transfer by convection. This combination of glass and gas in the 80 series results in a window that offers good energy efficiency, with a relatively low U value and a balanced solar heat gain coefficient. The 80 series is suitable for a wide range of climates. In moderate climates, it can effectively maintain a comfortable indoor temperature throughout the year. The dual layers of low-E glass and the argon gas fillings work together to provide insulation against both heat and cold.

125 Series

The 125 series has different glass specifications: 6mm low-E glass + 9Ar + 6mm low-E glass + 9Ar + 6mm clear glass. Although the thickness of the argon gas layers is slightly different from the 80 series, the 125 series also offers excellent energy performance. The design of the 125 series may be more suitable for certain applications where a slightly different balance of performance characteristics is required. For example, in areas with a higher emphasis on reducing solar heat gain, the 125 series may perform better due to its specific combination of glass and gas. The low-E glass in both series reflects heat back to its source, either outside the building in summer or inside in winter. The argon gas, despite the different layer thicknesses in the two series, still serves as an effective insulator, minimizing heat transfer through the window.

Tailoring Solutions Based on U-Value Requirements

We understand that different customers have varying U-value requirements, and we are committed to recommending the most appropriate specifications.

U-Value Requirement Lower Than 0.3

When a customer's U-value requirement is lower than 0.3, we recommend at least a thermal break + low-e insulated glass solution. A thermal break is a material that separates the interior and exterior parts of the window frame, reducing heat transfer through the frame. Combined with low-e insulated glass, this solution can effectively lower the U value of the window. The low-e glass reflects heat, and the thermal break in the frame prevents heat conduction. This is a cost-effective solution for many customers who want to improve the energy efficiency of their buildings without having to invest in more complex and expensive options. In many mid-sized commercial buildings or residential homes in areas with moderate energy efficiency requirements, this solution has been widely adopted and has shown good results in reducing energy consumption.

U-Value Requirement Around 0.25

If the requirement is even lower, around 0.25, triple-layer low-E glass and double-layer insulation are necessary. The additional layer of low-E glass further enhances the window's ability to reflect heat, both incoming solar heat in summer and heat trying to escape in winter. The double-layer insulation, which may include additional argon gas layers or other insulating materials, provides an extra barrier against heat transfer. This solution is often chosen for high-end residential properties or buildings in extremely cold or hot climates where energy efficiency is of utmost importance. For example, in luxury mountain cabins in the Rocky Mountains, where winters are harsh, or in high-end desert resorts in Nevada, where summers are scorching, this type of window can help maintain a comfortable indoor temperature while minimizing energy use.

U-Value Requirement Even Lower

For customers who require an even lower U-value, we consider UPVC window + low-e insulated glass. UPVC (unplasticized polyvinyl chloride) material is known for its extremely low thermal conductivity. In fact, the U-value of UPVC windows can reach as low as about 0.05. This makes UPVC an ideal choice for applications where the highest level of energy efficiency is demanded. In some environmentally conscious buildings, such as those aiming for LEED (Leadership in Energy and Environmental Design) certification, UPVC windows with low-e insulated glass are often used. These windows not only offer excellent energy performance but are also durable and require minimal maintenance. They can withstand harsh weather conditions, including strong winds, rain, and extreme temperatures, making them suitable for a wide range of locations across the United States.

In conclusion, our NFRC-certified aluminum windows in the USA, with their diverse series and customizable solutions based on U-value requirements, offer a comprehensive and reliable option for customers looking to enhance the energy efficiency and comfort of their buildings. Whether it's a small residential project or a large commercial development, we have the right window solution to meet the specific needs and energy goals of each customer.