Replace Old Illinois Windows to Gain Energy Efficiency


Studies show that 30 to 40 percent of the heat escapes through low-quality windows. At the same time, the cost of heating housing often takes up a large part of the family budget. Therefore, it is important to ensure thermal comfort in the house with the help of energy-efficient glazing so that these costs in an apartment building pay off, and in the case of private real estate, it allows you to pay as little as possible, but without reducing the standard of living. Residents in old buildings often have to deal with the problem of leaking windows. No matter how efficiently the heating system works, there will be cold air in such a room and there will be drafts due to heat leakage through a poor-quality seal.

IMPORTANT! In apartment buildings, it is important to pay attention to the glazing of the entrances and the tightness of the entrance groups. Such investments will allow not only significantly reduce the cost of heating the building but also to improve the quality of living in it.

It is a proven fact that the quality of windows has a huge impact on the temperature in the home and the cost of obtaining it. You should keep this in mind when planning renovations in an apartment or building a house.

In some cases, window replacement can be a profitable investment, albeit at a relatively high unit cost. The installation of energy-efficient windows today is a rational investment of funds and serious savings on their service in the future.

What energy-saving effect can you get from windows?

Currently, mainly plastic windows with double-glazed windows are installed.

At the same time, an energy-saving effect can be achieved through home window replacement with special glasses in the windows, which reduce thermal radiation. These are hard K-coated float glass (tin oxide) and soft I-coated glass (silver and dielectric nanolayer). The applied coatings provide a reflect of thermal radiation, hard ultraviolet radiation and are transparent in the visible part of the spectrum. This keeps your home warm in winter. The heat is reflected from the film coating and returned to the house. In summer, glass reflects the external heat flow of the sun’s rays and it becomes cool in the room.

A comparison of the thermal characteristics of insulated windows and with conventional double-glazed windows shows that a single-chamber double-glazed window with energy-saving glass is more efficient than a two-chamber double-glazed window. At the same time, double-glazed windows with I – glasses are more energy-efficient than with K – glasses.

K – glass is an early development of energy-saving glass. The energy-saving layer is applied chemically during glass production. The layer is hard, so this glass can be applied as a layer “out”.

I-glass is a high-quality glass with a low-emission coating applied to one glass surface in a vacuum, by the method of cathodic sputtering in a magnetic field of metal-containing compounds with desired selective properties.

A layer of silver is applied to the glass, and titanium oxide is used as a secondary coating. These films applied to glass are called “soft coatings”.

The use of double-glazed windows with i – glass and argon gas gives the following advantages:

  • protection from infrared radiation
  • high thermal insulation capacity: they retain heat in the room better by 60%
  • prevents the appearance of the effect of fogging of the inter-glass space
  • creation of a balanced indoor microclimate in summer, since I-glass prevents the room from heating, reflecting the sun’s rays
  • significantly reduces the cost of air conditioning and space heating

In terms of the cost of replacing windows, ordinary double-glazed windows and single-chamber windows with energy-saving glasses are about the same. The advantage of energy-saving double-glazed windows is that they weigh less, therefore they create less load on the window profile, and the deformation of window warping during service is much lower.

The use of energy-saving films.

The plastic window has already been installed, but there is a desire to reduce heat loss in winter or protect against overheating of the room in summer. For this case, manufacturers offer energy-saving mylar films that are glued to the glass. The principle of operation of the energy-saving film is the same as that of the energy-saving glass: light reflection in the IR and UV ranges and transparency in the visible part of the spectrum. Nano-coatings of rare-earth metals, silver, copper are used as a thermal mirror. They are invisible to the eye. The film itself appears to be slightly tinted.


After the new window installation, it becomes stuffy in the apartments. This is quite natural. There are no cracks, the doors are tight, there to get the necessary fresh air. 

In Europe, this problem has been felt for a long time. And they solved the problem technically by installing special devices called ventilators.

The ventilator solves three tasks at once:

  • provides a constant flow of fresh air into the room and removal of polluted air;
  • cleans the air by passing it through filters;
  • provides heating of the supply air from the heat of the exhaust air in the built-in heat exchanger.

When installing plastic windows, ventilators built into the window are offered with the possibility of heating the incoming air in the structural elements of the window. The cost of such a ventilator is not high, but its benefits are significant.