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PRODUCTION TECHNOLOGY FOR HIGHLY INSULATING EVACUATED WINDOWS

Objective


Evacuated glazing with extremely good insulation at a competitive price.

Considering small windows, i.e. less than 1 m{2}, evacuated glazing can be used in most frames and can substitute most existing glazing.

As regards large windows, the framing needs to be redesigned to the window. Adaptation of developed framing techniques will also improve the thermal performance of the window considerably. Development of a specially designed framing concept will improve the overall insulation of the thermal envelope even further.
Limited oil and gas reserves, economic and political risk with energy supplies, combined with the growing concern for the environment indicate an increasing demand for energy-conserving products. The primary advantage of evacuated windows is 5-10 times better insulation compared to double glazing. Half of this improvement is obtained by a vacuum in the cavity and the other half by low emission (lowE) coatings facing the cavity. Evacuated windows differ from ordinary windows in the following matters:

1. An absolutely airtight edge seal is necessary to contain vacuum.
2. Spacers are necessary to counteract the forces of atmospheric pressure and to keep the two layers of glass approx.0.2 mm apart.
3. Heat strengthened glass is necessary as the stresses in the window are much greater due to the vacuum, the large temperature differences and the rigid edge seal.
4. Vacuum to be established.
5. Low emission coatings must endure high temperatures and vacuum without degradation.

With a material consumption compatible with that of standard double glazing, the production process is the key factor for the price, and market share of evacuated glazing. Evacuated glazing is lighter and thinner(8mm)than double glazing. It can be installed in existing framles with the proposed insulating framing adaptor. If evacuated glazing replaces existing glazing whenever a window is replaced within 20-30 years (expected lifetime of double gazing) potential energy savings are 20% of the energy consumption for heating. Both the markets within EC/EFTA countries and in Canada, USA, and Japan are very interesting. In USA, two similar projects are expected to be launched late in 1993.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

DANISH TECHNOLOGICAL INSTITUTE
Address
P.o.box 141
2630 Taastrup
Denmark

Participants (1)

ST GOBAIN VITRAGE FRANCE
France
Address

60150 Thourotte