How to insulate windows so as not to lose heat? The answer is a bit complex because the structure of the window is complex. A window is not a whole as a wall can be. There is a transparent glass part and another part consisting of the window frame. And there can be a box for the roller shutter roller. This is why we technically speak of a 'window system'. The individual elements must be isolated one by one if you want to avoid heat loss and drafts. Let's see how.
How to insulate windows: the tightness of windows
It is somewhat true that drafts from the windows contribute to a certain extent to a healthy change of air, but they must be minimal. If the infiltrations are excessive, the result is that heat is lost and comfort is blessed.
Periodically check the gaskets placed on the door stops, and replace them when they are worn. There are also old windows without gaskets, which, however, can be easily installed. Small infiltrations from the frame can eventually be eliminated by applying silicone.
There are many insulating gaskets, one that seems valid to me and that adapts to different solutions is this: Insulating gasket for doors and windows
Or the 'grandmother's remedy', a set of 6 draft excluder sausages, with good value for money: Cotton draft excluder set
How to insulate windows: glass surfaces
If the windows have only one glass, you can replace the pane with double glass, but this is not always possible. An alternative is the installation of a second window in front or behind the old one, yet another is the complete replacement of the window with one equipped with an insulating double glazing.
A less expensive, and also simple, intervention consists in installing a reflective solar film on the window glass surfaces. It will not be the most effective of interventions, but it helps to stay warmer in winter and cooler in summer. In addition, the film improves privacy (there are opaque and colored ones), retains splinters in case of glass breakage and filters ultraviolet radiation.
How to insulate windows: the box
The box is one of the weak points of the window system because it is often not insulated. Fortunately, isolating it is quite easy and inexpensive too. The important thing is that around the roller shutter there is a space of at least a couple of centimeters (usually this is the case) to install an insulating element.
For example, here is a good solution, easy to buy and equally easy to assemble. Warnings: the width is 100 cm and if your box is larger you need two packs; if the box is smaller, the insulation can be shaped. Foam foam (not included) is recommended for fixing. Insulation for roller shutter
It is estimated that 10-15% of heating costs can be saved by installing gaskets on the door frames. 10-15% with the insulation of the bins. These are obviously 'spannometric' estimates, but the savings are there and certainly also increases comfort.
One thing to remember is that after carrying out any energy improvement intervention it is necessary to adjust the heating and air conditioning systems. If the intervention has been carried out correctly, the internal temperature will be closer to the comfort values and less energy will be consumed for the operation of radiators and air conditioners.
To discover (all) the drafts of windows and doors you can use the Thermal Draft Detector
And if the problem is the walls: How to insulate the walls and save
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