Can I improve existing double glazing?

With “old” double glazing, it will not be the glass itself that is worn out. Between those two sheets of glass there must be a layer of still air (it is this layer that actually provides the insulation). With old double glazing, the sealing of that air layer along the side will wear out, and will start to leak there. You can see a typical structure of double glazing with that seal in the attached drawing, which comes from a technical information from the BBRI (scientific and technical center for the construction company).

You can see that seal if you stand close to the glass and look at the edges. A typical phenomenon when that seal wears out is condensation between those two glass sheets, in the air cavity. At that moment, that air layer is no longer completely closed off from the outside air and so “humid” air seeps in, and the water vapor in that air will condense on your coldest glass surface.

Now suppose you want to improve your existing double glazing in terms of insulation performance by replacing the air with a noble gas (which they indeed often use in modern double glazing). The problem then is that you have to pierce that seal, which is already so fragile, to get your air out and put a gas in its place. And if your seal wears out, you will gradually lose your expensive gas to the outside air.

I think that given the cost of such an operation (due to the many working hours) and the risks involved, this would not be an efficient solution. But theoretically it is possible.

With new double glazing, both the gas in the cavity between the two glass sheets, the application of coatings on the glass sheets (which will reflect light and/or heat rays) and a better seal, will improve the insulation quality of the glass panel compared to “old” double glazing. glass.

I hope that answered your question.

Kind regards,

Leen Lauriks