Problem of preservation of heat, perhaps, the most actual for our region. Double-glazed windows succeeded windows with separate frames for improvement of heattechnical characteristics of rooms, but also it often it appears insufficiently to provide the comfortable thermal (temperature) mode indoors.

According to many researches, it is possible to draw a conclusion that through window openings of buildings from 40 to 50% of thermal energy are lost. Losses of heat through a double-glazed window happen by means of:

1) heat conductivity,

2) convections,

3) thermal radiation.

The main losses of heat fall on thermal radiation (to 70%).

To reduce losses of heat through radiation, our company offers energy saving double-glazed windows - in which applies glasses with a soft low-issue covering (i-glass). The special covering of such glass freely passes sunlight which heats furniture and other objects to the room, but reflects in the building the long-wave (infrared) radiation proceeding from heated objects and heating devices excepting thereby beam losses of heat through the transparent protecting designs.

Such selective nature of action of a covering allows to pass all heat going outside at the same time becoming a barrier on the way of heat leaving the room. At a temperature on the street of -26 °C and temperature in +20 °C, temperature on a surface of internal glass at a simple double-glazed window will make +4,7 °C, for a double-glazed window with low-issue glass of +14,7 °C. This property allows to avoid so-called "effect of a cold wall" and formation of condensate on double-glazed windows.

To understand efficiency of use of double-glazed windows we will provide the following data: application of double-glazed windows with a low-issue covering gives economy on the area of glazing of 30 sq.m of a house of 700 liters of conditional fuel a year, that is is twice less than at a glazing usual glass. At the same time the cost of a double-glazed window differs from a usual double-glazed window for only 5%.

Thus, main advantages of use of a double-glazed window:

• remains warmly indoors;
  
• costs of heating decrease;
  
• the microclimate improves;
  
• temperature in a priokonny zone increases;
  
• drafts decrease;
  
• the probability of loss of condensate at windows decreases.