Low E Glass Greatly Improves Your Windows Performance
What is Low E glass?
Low E glass is a wonderful new technology. Window glass underwent revolutionary changes in the 1970's. Insulated glass (two or more pieces of glass with a dead air space between) made its debut in the early 70s. Low E glass (Low emissivity glass) was introduced in 1979. Second generation Low E glass (dubbed Low E squared or Low E2) was introduced in 1983 with several companies claiming to have invented it. Since then the major glass companies have made improvements yearly. Low E glass works by reflecting heat back to its source. It does this by utilizing an ultra thin metallic coating on or in the glass.
What are Low-E Coatings?
Low-emittance (Low-E) coatings are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a glazing surface primarily to reduce the U-factor by suppressing radiative heat flow. The principal mechanism of heat transfer in multilayer glazing is thermal radiation from a warm pane of glass to a cooler pane. Coating a glass surface with a low-emittance material and placing that coating between the glass layers blocks a major amount of this radiant heat transfer, thus lowering the total heat flow through the window.
The benefits are a cooler home in the summer and a warmer home in the winter. Low-E coatings are transparent to visible light. Modern Low E coatings are very clear indeed, unlike the early brown tints we used to see. The infrared light(heat) from sun is powerful. When sunlight strikes an object it absorbs the infra red spectrum and heats up. Objects include sidewalks,rocks, anything outdoors that can absorb and radiate heat. As these objects cool off, they emit a low powered form of IR light. Low-E glass reflects this form of energy. Modern Low E glass senses summer by the angle of the sun in the sky and acts much like a heat mirror, keeping heat and damaging sun rays out.
In the summer this helps to keep your house cooler, as the heat from objects outside is kept outside. In the winter, Low E reverses the process and heat is reflected back into your house by the low-E glass. Different types of Low-E coatings have been designed to allow for high solar gain, moderate solar gain, or low solar gain and local window companies order glass custom made for our climate. Cardinal glass Low E2 172 is an example of a high end Low E(squared) glass customized for the Northwest. Someone in a very hot climate would choose a Low E coating designed to prevent summer heat with little concern for winter heat savings.
How Low E glass works for you in cold weather:
All objects emit energy as some form of radiation. Heat from a furnace, or even a person, is "long wave" radiation. Light from the sun generates "short wave" radiation. Thermaflect knows the difference. In cold weather, you spend your energy dollars generating long wave radiation. That heat moves toward your cooler windows, but Thermaflect acts like a mirror, reflecting it back inside to save you money. Thermaflect maximizes the beneficial energy of the sun. The coating selectively transmits the visible light (short wave energy) from the sun into the room, while reflecting away the ultraviolet radiation that can damage curtains and upholstery.
The short wave energy is then absorbed by objects such as sofas, carpets, even people, and is radiated from them as long wave heat. Thermaflect acts like a shield to this heat, preventing most of it from passing back out the windows! What's more, Thermaflect glazing with low conductance spacing is 10% warmer, saves 5% more heat, and reduces condensation up to 80%; so the room is more comfortable all around.
The total result for you is a better living environment and lower heating costs. With modern Low E squared glass the results are even more impressive! Cardinal glass and PPG's newest generation of Low E squared glass provide up to a 100% improvement over the first generation of Low E which was still very impressive. Glass just keeps getting better every day. Cardinal's LoE2-172 blocks 84 percent of the sun's harmful ultraviolet rays and delivers a remarkable 96 percent performance improvement in winter night time insulation (R-value) compared to non-coated air-filled insulating glass. However, it is virtually invisible to the eye.
How Low E glass works for you in hot weather:
Where vinyl replacement windows are exposed to direct radiation, Low E's (Heat Mirror unique multi-layered coating blocks unwanted ultraviolet radiation and reflects away infrared radiation that can add heat to the inside of your home and damaging rays that cause fade.In the summer, the sun is at a higher angle in the sky and less likely to stream directly into your window. Also, roof overhangs, trees, and tall shrubs serve to deflect sunlight from some windows, shield the more frequent use of blinds, drapes, and other window treatments also helps block unwanted heat.
But you still benefit from Low E glass. Sunlight becomes long wave heat radiation when it is absorbed by things outside such as your driveway, shrubbery, or patio. Low E glass acts a a shield to prevent this heat from entering your home through the windows, so your air conditioner does not have to work overtime.With Low E , you stay comfortable and your cooling costs stay lower - without sacrificing sunlight. Cardinal's Low E2-172 blocks 84 percent of the sun's harmful ultraviolet rays thus protecting your draperies, carpets, and furnishings from fading.
High Quality Low E glass
Our low E glass is of a superior quality and the warranty is excellent. Take the time to speak to a representative about your replacement windows needs and find out why our low e glass windows are the best.
