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New double glazing window sash


What is a Double Glazed Unit (DGU)? 

Two panes of glass with space in between that is filled with air or inert gas. The unit has either an aluminium or thermal spacer separating the two panes and is sealed tight with sealants. The unit helps to create a thermally insulated window. 

High performance Low-E double glazing Comfortglaze

Reduce Heat Loss Further With Low Emissivity Glass

Windows can reflect, take in, and transfer heat, so Low-E coatings can be used to enhance the performance of a window.

Low-E is a common abbreviation of “Low Emissivity”. Low Emissivity means a surface that gives off low levels of radiant heat. Therefore, a glass window with a Low-E coating will reduce the amount of heat transfer, making your house warmer in the winter and cooler in the summer.

Low-Emissivity Glass
Low-E Glass

U-values indicate the thermal conductivity of a material. 

A U-value is the inverse of an R-value, so if heat transfer through a material is minimal, its U-value will be low and its R-value will be high.



The diagram below outlines how heat passing through glass reduces as you improve the specifications of the unit. 

Window U Value diagram

R-values indicate the thermal resistance through a material.

With R-values, the higher the value, the better the insulation and the better the thermal performance.

Table E.1.1.1, shown below from the new H1/AS1 is a quick and simple tool for understanding the performance of your frame material and glazing combination.

Thermal performance Window Diagram



Added insulation provides your home with a moderate temperature all year round, reducing the amount of energy needed.


Your home is normally your biggest financial asset, COMFORTGLAZE high performance double glazing not only helps with comfort and energy efficiency, but it also increases the value of your home. 


High Performance Double Glazing keeps the cold out and traps the warmth in, allowing for a warmer, drier and healthier home.


You will benefit from reduced condensation on the insides of your windows. Your home will stay drier and healthier.


You'll notice a great reduction in outside noise, busy road noise or noisy neighbours can be a thing of the past.


Standard tinted or laminated double glazing reduces UV rays by up to 99%.


Reduces excessive summer heat gain allowing for a more moderated internal climate all year round.


"Excellent company to deal with. An example of how all businesses should be run. Excellent communication, very fast quotes, sharp prices, friendly service. Would recommend to anyone."

Sam, Cashmere 

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