Slimline Double Glazing For French Doors
Advantages of using Slimline Profiles for Doors
The technology of glazing a UPVC door frame is no different to other aspects of technology in that, over time, new developments are introduced which seek to improve the standards that currently exist.
Slimline double glazed frames are a modern innovation which have taken the concept to a new level.
Conventional double glazing consists of two layer of sealed glass which can have a gap between which may be as much as 25 millimetres wide. The cavity will be filled with dry air or an inert gas. The reduced thermal conductivity of the gas and the extra layer of glass will provide greater insulation than a single pane.
In slimline double glazing the sealed cavity between the two panes is greatly reduced resulting in a sealed unit that is significantly thinner than a conventional double glazed unit. All air is removed and a vacuum created. In production, air is sucked out of the glazing unit through a small tube in the corner of one pane of glass. This is melted and closed at the end of the process.
A typical thickness of a slimline glazed unit is in the order of 8.5 millimeters but can be less. In a standard double-glazed unit, a gap this small without the creation of a vacuum would continue to conduct heat but here it is said the glazing works in the same way as a vacuum flask – the vacuum eliminates the heat flow between the two glass plates
What are the benefits of Slimline Double Glazing?
The picture on the left shows how thick some glazed units can become, in this case it is with a triple glazed unit, With this reduced thickness, the Slimline units’ greatest advantage is that it is possible to use it in existing frames, where they were designed to be used with single panes and are unable to hold the thicker double glazed unit.
Fitting it into new glazed sections reduces the level of heat loss beyond that achieved by single glazing. This could be very useful if you are refurbishing an old set of French Doors with mullioned panes that you wish to keep.
To builders, architects and designers the introduction of this unit has come as a breath of fresh air. It enables the introduction of increased insulation and comfort factors associated with double glazing into situations that would present a problem using more conventional double glazed products.
As slimline double glazing can be carried out on existing wooden framed windows it is more likely to overcome the previous objections from Planning authorities in buildings that are listed or are in conservation areas. Window manufacturers can choose to use wood in new window construction using smaller timber sections. Fitted into existing windows it is possible to apply putty to fix the units in place.
One criticism of the standard or wide gap unit is that, to some, the glass is said to be noticeable. This is due solely to the thickness of the unit. With slimline products the glass is not visible and as such is considered more acceptable in listed buildings where outward appearance is often crucial.
The high performance slimline double glazed units produce a centre pane U value as low as 1.4, compared to a single glazed window u-value of 5.4. The heat insulation value is expressed as a ‘U’ value, the lower the u-value the better the insulation level. This lower level u-value easily conforms to the Building Regulation requirements thereby satisfying all local building control, planners and conservation officers.
It is inevitable with two similar systems, conventional & slimline that cost comparisons are considered. It is impossible to be specific when referring to the possible cost of Double glazing as every window and window opening has to be considered. We can however consider some generalisations.
When considering the relative cost of regular panels as opposed to Slimline panels it has to be said that the method of construction makes the Slimline glazing unit marginally more expensive per unit. However, this can be offset by the fact that the slimline unit used in new installations uses slimmer sectioned framing material thereby reducing that cost and balancing out the increased cost of the glass unit.
As the major benefit of slimline units is their use in a traditional existing window., cost comparison becomes something of an irrelevance as no other form of double glazing can be fitted into an existing opening.
In short slimline double glazing has a greater flexibility of use, and in certain circumstances may reduce costs by avoiding the necessity to replace a window whilst achieving the benefits of double glazing.