How a glass unit is put together

How a glass unit is put together

Keeping things in simple terms a glass sealed unit is two, or more, pieces of glass glued together with a gap in between to help create an insulating barrier to the outside weather, a definite bonus if you live in Blackpool or anywhere on the Fylde Coast during the winter months. Preston and its surrounding areas also come under close scrutiny of the weather too.


Obviously things are never quite that simple.

There is the glass itself. Treated or otherwise? Your glazing unit can have treatments applied to reflect heat back into the room. In addition, the coating also allows large amounts of solar energy to enter your building, thereby heating it passively. Low-E insulating glazing can therefore be a net contributor to energy in buildings.

Energy saving or toughened glass and even laminated glazing. When making your choice you need to have a chat with someone who knows the assorted options and what would suit your particular requirements. The window specialist would also need to take accurate measurements so the glass unit would fit perfectly, either into the existing uPVC frame for a glass unit replacement or for a new frame entirely.

Other benefits of a double, or triple, glazed glass unit are noise reduction and stopping unwanted excessive heat from the sun. Another benefit is the added security.

The air gap also has options. It can be just a simple dry air sealed, or it can be gas filled.

As a starting point let us look at how the glass units are out together.


Standard Double Glazed sealed units

A standard double glazed sealed unit is created by placing two pieces of glass together with a spacer bar in between the glass. 

That was easy, but what about the spacer bar? These come in a range of lengths and determine the thickness of the glazing unit. The further apart the glass then the warmer the inside piece of glass will be. However, you need to balance this thickness with how the unit will look once installed.

Inside of the spacer bar are placed small absorbing desiccant beads that help rid the sealed unit of any moisture if any moisture should enter the glazed unit. Moisture within the glass units appears as condensation and may be called a ‘blown’ window.  This is where the seal has been compromised allowing condensation in, it also means the glass unit will not be working as effectively as it should be.  This is more generally seen in older or damaged units. A black hot melt glue Sealant is then applied to the outside edge of the glass to bond the two pieces of glass together and also to keep the spacer bar in place. 

Then there is the air gap.

This can be dehydrated air, argon, krypton or xenon. Different glasses have different benefits.


Triple Glazed sealed units

Triple glazed units have a better energy saving rating than double glazed units because there are now 3 pieces of glass for the cold to travel through before it gets into your home. Triple glazed units are almost 50% heavier in weight than a double glazed unit so this needs to be taken into consideration when ordering large windows. Though the construction of a triple glazed glass unit is similar.


So as we spend the bulk of our time indoors, unless you get lovely summers in Blackpool and Preston, to enjoy the beaches and parks, the insulated glass units create comfortable homes, with a security to go with the nice aesthetics.


If you’re interested in replacing a window for your home, take a look at our New Window packages. Alternatively, just take a look at our other services for more!

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