F.A.Q's

Q/ Can any decrorative product be bonded to any Low-e glass?

A/ No. We believe that Bevels and Lead designs can be bonded to Low e glasses but feel that this could bring potential problems to the unit. We feel the best solution is to only decorate glass when we have a piece of clear float to bond to.

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Q/ Is it possible to incorporate products or add-ons inside of the unit and still meet the required U-value?

A/ Although we have not received anything in black and white we feel that georgian bar, fan holes etc. can still be accommodated into a unit.

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Q/ Do the requirements extend to repair work on existing windows

A/ No. The new Document L only applies when the whole window is to be replaced. Replacement of just the glass or part of a damaged frame is exempt from the regulations and the replacement can be carried out on a like for like basis. However, other regulations, such as those affecting safety glazing, will still have to be respected.

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Q/ Which obscure glass can be leaded both sides?

A/ The only types of obscure glass that can be leaded both sides are listed below:

Please remember that no type of obscure glass can be bevelled. If you wish to have low e, activ or obscure you must have a clear flat surface. Therefore you will have to triple glaze.

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Q/ How is heat lost through a sealed unit :

A/ Conduction

In a sealed unit, heat can pass via conduction through the inner pane of glass, across the air within the cavity of the sealed unit and through the outer pane of glass to the outside. To reduce this type of heat loss there have been some changes to early sealed units:

• The cavity between the glass has gradually been increased over the years from around 6mm to an optimum of 16mm to 20mm. This slows down the heat loss as the heat has to cross a wider cavity area.
• Low e glass has been introduced for one of the panes having the effect of reflecting the heat back into the building and therefore reducing heat loss.
• An inert gas such as Argon can replace the air in side the cavity. Argon, being inert, further slows the heat loss across the sealed unit (Argon has low conductivity and is denser than air).
• Triple glazing may be used, increasing the distance and mediums heat has to pass through to reach the outside.

Convection

Heat from inside the building heats up the air within the sealed unit cavity. This causes the air to rise within the cavity, beginning a circular movement of air that heats up and rises then cools and falls increasing the heat loss by moving the heat faster across the cavity due to this air movement. Ways to reduce this heat loss include:

• Don’t have too large a cavity, 16mm – 20mm are the optimum.
• Use an inert gas within the cavity.

Radiation

Heat within the building radiates to the outside. This type of heat loss can be reduced by:

• Using Low e glass, reflecting the heat back into the building

If you have any unanswered queries don't be afraid to contact us