Windows and doors are the most essential part of a house. From keeping your home secure and guarding it against the harsh elements of nature to letting in sunlight and ventilation — these fixtures do it all. However, just installing doors and windows is not enough. It’s important to glaze them too. There are various types of glazing for different kinds of windows and doors available. You need to research well and choose the best glazing option for your home.
Why is glazing important?
Glazing helps minimize heat loss, air leakage, and lower condensation. What’s more, it helps cut down on your energy consumption drastically because it makes your home more energy efficient — reducing too much heat transfer.
Let’s explore the various types of glazing available for your home.
Types of glazing for windows and doors
Single Glass Glazing
As the name suggests, a single glaze is made up of just one layer of glass. Generally, its thickness ranges from 3/32” to 9/16”. For the longest time, it was the only viable glazing option. Thankfully, as people became more and more aware of global warming and the increasing need for efficiency — its popularity dwindled.
The reason was simple. Solar energy – both light and heat– easily passes through this glass. Therefore, energy loss is considerable. Such glazing provides very little energy efficiency with only an R-1 insulating value.
The only selling point for single-glazed doors and windows is that they are cheaper to install. However, don’t get influenced by the pricing. In the long run, it may cost you extra dollars to heat and cool your household with only single panes of glass or glaze.
Double Glass Glazing
Double glazing windows have two panes of glass. Therefore, they can help with insulation as well as noise reduction to a large extent. They retain heat and keep out the cold more effectively and efficiently. You can save energy savings — leaving a smaller carbon footprint.
The best part is that such a window or door lets in as much light as a single glazed one. And, the extra space between the glass acts as additional insulation.
Triple Glass Glazing
Today, this kind of glazing is found in most urban houses. Triple glazing uses three panes of glass and the extra panes help in increasing efficiency. It helps keep more heat in and cold air out, making this the most energy-efficient glass option.
It is the perfect choice for colder climates where most part of the year is spent heating the living space. And, it reduces noise transmission to a huge extent.
Thus, triple glazed windows and doors are a great option for people who are concerned about both the economy and the environment.
Now that we have understood the three basic types of glazing for windows and doors, it’s time for a lowdown on the kind of glass varieties that are ideal for glazing. Here are some types of window glass for your home.
Photo from Pixabay
Float glass is formed when molten glass is made to turn into large, flat panels. The process is technical whereby molten glass is floated on molten tin. But it produces the smoothest, largest, and one of thinnest glass panels.
This is a basic sheet of glass before it is cut, treated, upgraded and set into a window frame. It is the starting material for your windows and doors. The best part is, it is low-cost and colorless and can be easily modified.
Safety Laminated Glass
Laminated glass holds together even when shattered. The layers of glass bond in such a way that the high strength prevents the glass from breaking into sharp glass shards. It produces what can be called a spider web crack. Skylight glazing and automobile windshields use laminated glass for this safety feature.
The reason this is an extra-strong, security-enhanced glass is that it is created by fusing two or more panes with an inner layer of polyvinyl butyral (PVB). This process uses very high heat and pressure to make the super-strong panel.
What’s more, the PVB interlayer ensures a much higher sound insulation rating. And, it blocks 99% of UV light! It’s also a strong barrier against forced entries.
Apart from safety or security reasons, this glazing is suitable for geographical regions that require hurricane-resistant construction.
As the name suggests, obscured glass allows light to come in but is not completely see-through. This glass may be frosted, etched, or coated. You may not be able to look through it but may see vague shadows of what’s behind. This is the most popular type of glass for bathroom windows, shower doors, and entry door areas. While they may not offer 100 percent privacy, they let in more natural light indoors. A huge advantage.
A glass becomes annealed if float glass is heated above a transition point and then allowed to cool slowly, without being quenched. This annealing process is slow, meticulous and controlled. Its purpose is to strengthen the glass by reducing the stress caused to it by quick cooling.
While it is strong, annealed glass is not the ideal choice for windows, as it may leave jagged shards or sharp pieces if broken. This can cause serious injury. No wonder, many Building Codes restrict the use of annealed glass. You will seldom find such glazing in bathrooms, door panels, fire exits, or schools.
Tinted glass is any kind of glass which has coloring added. It could be bronze, green, blue or gray. Apart from adding value to the design and aesthetics, it gives more privacy to your living space and reduces heat from sunlight. Thus, it offers good protection against harmful UV rays. The tint doesn’t affect the basic properties of the glass except for solar energy transmission.
This heat-absorbing glazing blocks a significant amount of incoming solar radiation. Thus, it reduces the solar heat gain coefficient, visible transmittance, and glare.
If you want to ensure that minimal heat is allowed to pass through tinted windows and doors by conduction and re-radiation, you can install inner layers of clear glass or apply spectrally selective coatings to further reduce heat transfer.
Tempered glass is actually annealed glass — but with four to six times as much strength! The process is again technical; glass is heated to above 1200 degrees. It is then quickly cooled.
This method tests the glass before it’s used in any real-life applications. The manufacturers take no chance of it being unstable. It usually shatters in small, square pieces and not jagged shards when broken. If strength, thermal resistance, and safety are your concerns, tempered glass is a safe bet.
Heat Strengthened Glass
When you need a tougher glass (twice as much) than annealed glass panels, heat strengthened glass is your solution. In simple language, it is an intermediate in strength between annealed and tempered glasses. Here, an annealed glass is reheated above 1200 and then cooled. But, it is not cooled as quickly as tempered glass.
Maybe that’s why it’s not as strong. However, it is tougher than most lower grades of glass. If you want to use it for your exterior windows and doors, be sure to laminate it — else it might shatter and break into sharp pieces on impact.
Insulated glass windows and doors are the most optimized ones for energy efficiency. Manufacturers, in order to improve the thermal performance of such glass, use a process called gas fill. They fill the space between the glass panes (usually laminated or tempered security glass) with non-toxic, inert, non-reactive gases such as argon and krypton.
The logic is simple — these gases have a higher resistance to heat flow than air and are sealed between the window panes to decrease the rate of heat loss aka U-factor. The lower the U-factor, the greater a door or window’s resistance to heat flow and the better its insulating properties.
Insulated glass is a great choice for exterior glass. It helps you keep your heating and cooling costs down. That said, all insulated glasses are created differently. Do compare your options for the best energy efficiency ratings or energy star ratings.
Read more: Double Hung Windows: What You Need To Know
Mirrored or Reflective Glass
For this mirrored effect, the glass panel is given a metal coating on one side. It is then sealed with an extra protective sealant. Interestingly, it merely reflects heat and radiation rather than absorbing it. It does reduce heat gain and visible light transmission, but not significantly. No wonder, such glass is used more in a decorative capacity than utilitarian. You will find reflective walls and doors but not many exterior windows.
Low emissivity or Low-E glass reflects thermal radiation and controls heat transfer. Typically, insulated glass is treated and covered in low-emissivity coatings in such a way that it keeps out infrared rays, while allowing light to filter through — lowering your window or door’s U-factor.
This coating is a thin, almost invisible layer with metal or metallic oxide. It is applied to the outside pane of glass when you want to keep the sun’s heat out. On the other hand, if you want a lot of heat energy in winter and keep heat inside the house, this coating must be applied to the inside of the glass pane.
Low-E coating can be a soft or hard coat. While soft has a limited shelf life and is easily damaged when exposed to air and moisture — hard coat is more durable. However, its energy performance is poorer than a soft coat.
Generally, Low-E coatings cost about 10%–15% more than regular glass, but they prove to be profitable in the long run — reducing energy loss by as much as 30%–50%.
Wire glass may not be a security glass, but it’s fire-resistant! This is the reason it’s the most common type of glazing in schools, hospitals, and commercial buildings. This glass is built in such a way that the wire grids will actually hold the glass in its frame if it shatters under high heat. What’s more, it can withstand a firefighter’s hose without blowing out shards everywhere. That said, while this glass is perfect for a commercial set-up, it might not be so for your home.
There are other glaze options too but they are not as commonly found (or practical) like the ones above. Let’s briefly look at some of them.
This is more of a decorative glass than utilitarian. Manufacturers achieve this effect by sandblasting, acid etching, or just by applying a film to the surface. The idea is to make the glass less transparent for privacy or aesthetic reasons.
The amazing glass has a special chemical coating. It reacts with daylight to break down organic dirt — cleansing itself via daylight and rain.
This glass comes with a patterned UV reflective coating. The best part is, it is visible to birds while remaining virtually transparent to the human eye.
Electrochromic Privacy Glass
Here’s another glass that is unique. It turns opaque or translucent with the flip of a switch. Yes, you read right. Manufacturers apply electrodes to the inside of the glass unit. When an electric current runs through it, the ions react and move to reflect light.
Now that you know about the types of glazing and the latest glass technology — you can easily choose the perfect fit for your doors and windows. Before you begin with the work, it’s best to get a window replacement cost estimate too. We are sure, your selection will make your home attractive, secure, and environment-friendly.