Home - Tips on window purchase - Saving energy - Triple glazing

Triple glazing

Passive houses have long used triple glazing as standard. Conventional new buildings or renovated buildings can also benefit from several advantages offered by triple glazing and owners should consider these when deciding which products to buy. Triple glazing excels with the following properties:

outstanding insulation values: U_g to 0.4 W/m²K
Reduced heating costs
Enhanced living comfort (warm surface, no draughts)
Optimized solar energy yield
High light transmission for natural light in the living area
No visual difference to double glazing

Triple glazing can be used for all our window systems.
Click here to find out more!

Saving energy and money with triple glazing

Old and single-glazed windows let in the draught and are responsible for high heating costs. The thermal insulation of modern windows is much better than it was a few years ago. Here a comparison: a window with single glazing from the early nineteen eighties had an average heat transfer coefficient of approx. 5-6 W/m2K. Today, windows are not allowed to have a Uw-value greater than 1.3 W/m2K, already due to the Energy Saving Regulation (EnEV 2009). For the future, Uw-values of ≤ 0.95 W/m2K are already being considered. This corresponds to a saving of more than five times the amount of energy. This is the only way to reduce heating costs and energy consumption effectively. Today, the extra cost for triple glazing is minimal and amortisation is quickly accomplished through higher energy efficiency.

CO2 and heat cost savings using the Eforte window system as an example

Eforte	Standard version with steel reinforcement
U_f (frame)	0,95 W / m²K
U_g (triple glazing)	0,6 W / m²K
U_w (window)	0,8 W / m²K (Passive house standard)
Saving	1120 litres heating fuel / annum
Saving in heating costs in the first year	784,– Euro
Reduced CO2 emissions per annum	2240 kg / year

Calculation example in comparison with an old window with insulated glazing (U_w-value 2.8 W / m²K), standard window 1.23 m x 1.48 m. Basis for heating cost calculation: fuel costs 0.70 Euro / Litre, window area 50m².

There are more than financial advantages for the residents. Modern apartments and houses with triple glazing also provide noticeably enhanced comfort and cosier living.

The financial savings when replacing your windows can be calculated with our energy saving calculator.

Enhanced comfort and cosier living with triple glazing

We all know the feeling. In the cold season we sense a cold air flow in the proximity of windows. We get colder in areas around windows and turn up the heating more than needed. The sense of well-being is not only a function of the room temperature and air flows, it is also influenced by the temperatures of the floor and wall surfaces and also of the windows. A larger temperature difference between the individual surfaces results in the colder surfaces drawing heat off the warmer surfaces. People notice this in the form of skin cooling, and this has an impact on our sense of temperature. Triple glazing has a substantial impact on both the air flow and the surface temperature.

Thermal comfort with triple glazing

Low heat losses that provide us with thermal comfort are due to the high insulating values of triple glazing. In a triple-glazed window the intermediate spaces between the glass sheets are filled with rare gases that have low thermal conductivity. This means that only very little heat transfers through to the outer glass sheet where it can escape. The temperature at the inside sheets is therefore correspondingly high.
According to a study carried out at the Testing Institute in Rosenheim (ift) in which double glazing was compared with triple glazing at an outside temperature of minus 10 degrees centigrade and a room temperature of plus 20 degrees centigrade, the temperature difference was almost 9 degrees. The double glazing had an inside surface temperature of 9.5 degrees, the triple glazing had an inside surface temperature of 17.7 degrees. As a result of the minor difference of the inside surface temperature to the room temperature and the other surface temperatures the feeling of well-being is enhanced substantially. There is no air flow, a “lake of cold air” does not develop putting an end to all shivering near windows.
People who are planning a new building or renovation work should seriously consider triple glazing and ask for quotes to compare prices.

You will find further information on this topic on our Info Page Passive house windows or on the internet under www.passiv.de oder www.ift-rosenheim.de