Window Repairs Guides & Resources

Low-E glass vs double glazing

Window insulation is an important factor in keeping your home comfortable and energy-efficient. There are a few different types of window insulation, but one of the most popular is double or triple glazing. Unlike single glazed windows or triple glazed units, double glazed windows consist of a secondary glazing including two glass panes with a small air gap in between. This small air gap is filled with air or inert gas, which helps to improve the insulation of the window, making it an energy efficient glass with reduced energy costs. Low e glass is a newer type of window insulation that is becoming more popular. Low e glass is made with a special coating that helps prevent unwanted heat gain from the window. This helps to keep your home cooler in the summer and warmer in the winter, reducing heating and cooling costs. Low e glass also helps to reduce glare and improve visibility with more efficient thermal performance. There are a few key points to consider when deciding between low e glass vs double glazing, which is the best solution for your home: ### Heat transfer Low-E glass has a less heat transfer coefficient than double glazing, meaning it is better at preventing heat loss in winter and keeping your home comfortable with better thermal efficiency. However, double glazed windows are more efficient in places where heat transfer occurs through the surrounding atmosphere. ### Noise reduction Double glazing is better at blocking noise from outside, making it a better choice for homes near busy streets or airports. However, it's important to note that this might slightly reduce the thermal performance of your windows. ### Visible light transmission Low-E glass allows more natural light into your home, making it better at visible transmission f you want to reduce your energy usage. ### Solar heat gain Low-E glass can help to reduce solar heat gain in summer, keeping your home cooler and reducing your need for air conditioning in warmer climates. ### Condensation Low-E glass reduces the risk of condensation forming on your windows. ## Benefits of double glazing Benefits of double glazing or insulated glass units include the below. ### Reduced noise pollution Double glazing is much better at blocking out external noise than low e glass, which makes it the perfect choice for homes near busy roads or airports. Though, the air space used to improve noise reduction might slightly reduce the thermal performance of the window. Double glazing can also help to keep your home warmer in winter by reducing heat transfer through the windows. ### Increased energy efficiency and solar heat gain The design and structure of double glazing reduce the risk of condensation forming on your windows, meaning they are less likely to be damaged by damp which can reduce energy loss from your home and increase its energy efficiency. Moreover, double glazed windows absorb and reflect solar radiation more efficiently, making them one of the most energy-efficient windows. ### Extra insulation There are a number of ways that you can add extra insulation to your home if low e glass or double glazing don't offer enough insulation on their own. You can add insulation to your walls, roof and floor, or you can install window shutters or blinds to help keep the heat energy in during winter and the cool air out during summer. High performance aluminium frames can also be incorporated with an existing window frame to drastically reduce heat transfer through window frames. ## How much more does Low-E glass cost? Low-E glass is a more expensive type of window insulation than double glazing. The price can vary depending on the supplier, size and quality of the Low-E glass that you choose. The cost of Low-E glass is usually around 10% higher than the price of double glazing. ## Is low-e glass or double glazing more energy efficient? Double glazing unit or insulated glazing has a lower heat energy transfer coefficient, meaning it is better at preventing heat loss in winter and keeping your home warm. But low-E glass lets in more visible light, which makes it the better choice if you want to reduce energy usage by using less artificial lighting. Low-E glass also reduces condensation on your windows thanks to its coating that helps keep out moisture. If you are looking for insulation that's good at keeping the heat in, then Low-E glass is the better choice. However, double glazed windows are better at reflecting and absorbing solar radiation resulting in a better SGHC (Solar Heat Gain Coefficient) and less solar heat , so if you want to reduce winter heat loss and energy usage while keeping your home light and bright with radiant heat, then double glazed windows are a better option. Moreover, double and triple glazing can also be added to your existing windows by doing a secondary glazing over them. You can refer to the Window Energy Rating Scheme of both the windows to help determine which window system fits your needs best and provides the best energy efficient glazing system. ## What does the E in Low-E glass mean? The 'E' in Low-E glass stands for emissivity. It is a rating of how well an object allows thermal radiation to pass through it and the lower the number, the better the insulating properties. ## How does Low-E glass work? Low-E glass has a thin, transparent layer of metal oxide on the glass surface of the outer pane. This coating reflects heat away from your home to help keep it cool in summer and warm in winter. The amount of heat blocked by a low-E coating is subjected to the type of low-E coatings your glass has. Low-E coating can also be paired with your existing windows that are single glazed windows or double glazed windows to drastically improve the overall performance of the window. ## What is Low-E glass coated with? Low-E glass is made with vanadium oxide, silver or tin-doped indium oxide. These three metals have different levels of emissivity. Tin has the lowest level followed by silver then vanadium. The best insulation results are achieved by using two pieces of Low-E glass that are both coated with either tin or silver rather than one piece of Low-E glass coated with tin and another piece coated with vanadium. ## Is window tinting a good insulator? Window tinting and light tinted glass is not a good insulator on its own, but it can help to reduce the amount of heat loss through windows if it is combined with Low-E glass or double glazing. Tinted glass can also help to keep your home cooler in summer by reducing solar gain. Moreover, window films can also be attached to existing glazed window glass to improve their thermal performance and overall heat flow efficiently. ## How do you clean Low-E glass? Cleaning Low-E laminated glass is not any different from cleaning other types of glazed doors or windows. You can use a regular window cleaner or a solution of vinegar and water. Be sure to avoid using any abrasive cleaners or cloths, as they can damage the coating on the glass. ## How is low emissivity glass made? Low emissivity glass is made by applying a clear, thin metallic oxide layer onto the surface of one or both pieces of window glass. The type and thickness of the gas between the two sheets of glass affects how well Low-E windows insulate your house in winter and summer. The metal oxide used in Low-E glass can be vanadium, silver or tin-doped indium oxide. Vanadium oxide has the lowest emissivity and is the cheapest to produce, but has a purple-grey appearance. Silver has a higher emissivity than vanadium, but it costs more to produce. It also tarnishes over time, which gives it a slightly blue colour that many people do not like. Tin doped indium oxide is the best choice for Low-E windows because of its high emissivity and its natural grey appearance, making it virtually indistinguishable from normal clear glass. Additionally, it's vital to understand how different window styles help amplify or minimise the benefits of these systems. For example, casement windows and awning windows seal better, providing better air leakage control than sliding windows doors.