IG Units
The best vinyl window replacements are built using an insulated glass unit, or IG. Insulated glass units are two to three individual glass panes that are bonded to a spacer bar by sealant. It is a great idea to always ask about the insulated glass unit so you can locate the one that will be high quality and have the best performance.
Low-E
Another important element to consider when searching from the best vinyl replacement windows is to look for ones that are low-emittance, or Low-E. These are layers that are thin, usually made of metal or metallic oxide, and are primarily used to reduce the U-factor by limiting the amount of heat flow occurring in the glazed window. In order to block an exorbitant amount of radiant heat transfer, the inner glass surface should be coated with a low-emittance material. While remaining transparent to visible light, many different forms of Low-E coatings are on the market. The variations allow for low solar gain, moderate solar gain, and high solar gain. In vinyl windows, Low-E is generally recommended for only sides of the home where the sun is likely to shine more. The best vinyl replacement windows often have a tint to them.
Low Conductive Gas Filled Units
Using krypton or argon gas between the panes of glass has been reported to make a significant improvement when it comes to insulation. The best vinyl replacement windows will have space that is consumed with dry nitrogen or air before the window panes are sealed together. To reduce the total amount of heat transferred between the inside and outside of the windows, it is recommended to fill the space with gas that is less conductive. Argon is ideal for this endeavor, as it is nontoxic, inexpensive, odorless, clear, and non-reactive. About 1.5 to 1 inch is the ideal amount of spacing an argon-filled unit should use.
Although the thermal performance of krypton is generally better, the production costs are much higher. When the space needs to be thinner than normal between the gazing, krypton is the perfect choice. Using units filled with conductive gas is associated with numerous insulating benefits, but the cost is higher.
What is U-Factor?
The best vinyl replacement windows have a low rate of heat loss, which is indicative of the U-factor, indicating how a window was assembled. When a window has a lower U-Value, the window is better at insulating and will resist heat flow much more efficiently.
What is the SHGC Factor?
Solar Heat Gain is the percentage of the total amount of heat gained from solar energy that penetrates glass. The percentage is calculated based on the amount of heat gained from a combination of absorbed heat and direct sunlight. A small number indicates that the unit is more capable of reducing solar heat gain. The lower values also help to reduce your air conditioning bill in the summer since less heat is absorbed. Depending on the glazing options, the best vinyl replacement windows will have ratings ranging between 0.91 to 0.39. A SHGC of 0.98 is average for the typical single paned wood framed window.
Visible Light Transmission (VT)
VT, or visible transmittance, is a key indicator in determining how much visible light is transmitted. This rating is for the entire window, including the frame. The best vinyl replacement windows will have a high VT, which is ideal during daylight hours. Most values are usually between 0.3 and 0.8.
The previously mentioned terms are all very important to become educated on before you make your purchase. Not only is purchasing a high quality window vital to how the windows will perform, but the installation is equally as important. Poor installation can be responsible for your windows performing poorly, even if they are high quality windows. The best vinyl replacement windows will be taken care of to provide you with an excellent performance that will last for years to come!