Fitting sealed double glazing units will provide good heat and sound insulation as well as reducing draughts. They are easy to install in either existing or replacement window frames.
It is well known that double glazing offers considerable benefits for the homeowner. It can considerably reduce draughts from around the window area, not only those which enter through badly fitting frames but also down-draughts caused by warm air close to a cold, single pane of glass being quickly cooled and so falling.
Eliminating these down-draughts makes for a more comfortable environment and prevents that ‘chilly’ feeling even though the room is heated. Some forms of double glazing can, to some extent, also reduce the penetration of noise from outside the building, but the major advantage is that the use of two panes instead of one can help reduce heat losses through glazed areas, providing a potential for saving energy and, hence, cutting fuel costs.
By far the most efficient method of achieving such thermal insulation is by the fitting of sealed double glazing units in place of single panes of glass in the window frame. This is known as primary double glazing.
Each sealed unit comprises two sheets of glass separated by a metal, glass or rigid plastic spacer which is fitted around the edges. The air between the two panes is dehydrated so that it contains no moisture, and the entire unit is sealed hermetically so that none can enter. As long as the seal remains unbroken condensation cannot form between the two sheets of glass. The space between the panes normally varies between 6 and 12mm (1A and 1/2in), the wider gap providing the best thermal insulation properties.
The glass itself will vary in thickness from 3mm upwards depending on the size of the pane and the position of the window, many different types being available including float, laminated, toughened, standard sheet, tinted and obscured. All sealed double glazing units are factory made by specialist companies and cannot be assembled at home. However, they can be fitted by the non-professional glazier in much the same way as normal replacement panes of glass either to existing window frames or into completely new replacement windows.
Local glass merchants and double glazing manufactures are involved in the supply of sealed double glazing units in a wide range of standard sizes or in made-to-measure form to suit individual requirements, and it is now common practice for complete replacement windows, made from wood, aluminium or UPVC, to be supplied with sealed glazing units fitted as standard.