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Thermal Insulation

1st Secondary Double Glazing products provide Excellent Thermal Insulation.

They are Suitable for Installation into Windows & Doors of all types in both Commercial & Residential Properties.


The Facts

Around 20% of a Homes Heat Loss is via Single Glazed Windows

http://www.gozero.org.uk/files/A_Guide_to_Home_Energy_Saving.pdf

Standard Double Glazing will about halve that heat loss

http://www.energysavingtrust.org.uk/home_improvements/home_insulation_glazing/glazing


The Figures

U Values Explained


Thermal transmittance is a measure of how much heat will pass through one square metre of a structure (door or window) when the air temperatures on either side differ by one degree.

This measurement is known as the U-value. The lower the U-value, the better the level of insulation, and vice versa.

  • Domestic Dwellings - Under Building Regulations Part "L" Replacement Windows & Doors must have a U-value of 2.0 or less.

  • Buildings Other than Dwellings - Under Building Regulations Part "L" Replacement Windows & Doors must have a U-value of 2.2 or less.


Typical U Values By Primary Window & Glazing Type


Frame Type
Thermal
Break
Glazing
Glass
Cavity
Cavity Gap
U Value
Range *
 Metal
No
Single
Float
-
-
5.7
 Wood
-
Single
Float
-
-
4.8
 Metal
No
Double
Float
Air Filled
6, 12 or 16mm
4.0 - 3.6
 Metal
Yes 4mm
Double
Float
Air Filled
6, 12 or 16mm
3.7 - 3.3
 Wood or PVC-U
-
Double
Float
Air Filled
6, 12 or 16mm
3.1 - 2.7
 Metal
Yes 12mm
Double
Low E
Air Filled
6, 12 or 16mm
3.1 - 2.1
 Wood or PVC-U
-
Double
Float
Argon Filled
6, 12 or 16mm
2.9 - 2.6
 Wood or PVC-U
-
Double
Low E
Air Filled
6, 12 or 16mm
2.7 - 1.8
 Metal
Yes 20mm
Double
Low E
Argon Filled
6, 12 or 16mm
2.7 - 1.8
 Metal
Yes 20mm
Triple
Float
Air Filled
6, 12 or 16mm
2.6 - 2.2
 Wood or PVC-U
-
Double
Low E
Argon Filled
6, 12 or 16mm
2.5 - 1.7
 Metal
Yes 20mm
Triple
Float
Argon Filled
6, 12 or 16mm
2.5 - 2.1
 Wood or PVC-U
-
Triple
Float
Air Filled
6, 12 or 16mm
2.4 - 2.0
 Metal
Yes 20mm
Triple
Low E
Air Filled
6, 12 or 16mm
2.3 - 1.5
 Wood or PVC-U
-
Triple
Float
Argon Filled
6, 12 or 16mm
2.2 - 1.9
 Wood or PVC-U
-
Triple
Low E
Air Filled
6, 12 or 16mm
2.1 - 1.4
 Metal
Yes 20mm
Triple
Low E
Argon Filled
6, 12 or 16mm
2.0 - 1.4
 Wood or PVC-U
-
Triple
Low E
Argon Filled
6, 12 or 16mm
1.9 - 1.3

* U Value Range
The Range is determined by the Cavity Gap & the Type & Thickness of the Low E Glass Coating.
The bigger the gap the better up to approximately 13.2mm for Air Filled units after which air circulation within the Sealed Unit cancels out any gain from reduced conductivity.

Low E glass is available in Hard Coat & Soft Coat versions with different thickness coatings. Coating thickness makes a negligible difference to the Insulation Value - Soft Coat is more effective than Hard Coat but NB that it is less durable & quite easily damaged or marked during handling and processing.

This is the Current Standard for over 90% of the Replacement Windows being installed in the UK today.


Amongst other sources you will find a Table of U Values on the following Link, Page 65:

http://projects.bre.co.uk/SAP2005/pdf/SAP2005.pdf



 
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The Solutions

Obviously you can fit Replacement Double Glazing, however, if your existing windows have not reached the end of their useful life but are Draughty & Inefficient, then Replacements are not the Most Economical or Environmentally Friendly Solution.

In this Scenario, Secondary Glazing will provide an Equally Effective solution, at less Cost to Both You & The Environment.

Standard Secondary Glazing using Float Glass over a typical primary window will achieve a U Value of about 2.5.

1st Secondary Glazing with a 4mm Low E Hard Coat glass will achieve a U Value of 1.868 - equal to the majority of Replacement Double Glazing!



Change of Use (Building Regulations L1)


We can supply Rated Secondary Glazing that Complies with the Requirements for Change of Use.

For more Information or Specific Enquiries please call or Contact Us




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