Saving energy with doors and windows

Leaky windows and doors can quickly drive up energy costs. How to seal them and save money: A guide.

Especially in cold temperatures or on windy days, it is easy to find out how tight window and door frames are. If frost flowers form on the windows on cold days, this is a sign of poor insulation. Tarnishing of the windows in double-walled windows also indicates leaky windows. Test the seal: Hold a tea light to the window frame - if the flame flickers, the window is leaking at this point. The paper test can also be revealing: clamp a sheet of paper between the window and the window frame and pull it out. If the sheet of paper is difficult or impossible to pull out when the window is closed, the window frame is leaky. If you can remove the paper without problems, the window frame does not close properly and is leaking.

With the help of sealing tapes made of rubber or foam seals, leaky windows and doors become tight again. As a short-term or long-term solution, the seals can be easily stuck to the frame and removed again. To estimate how much sealing tape you need, measure the window frames with a folding rule. Sealing tape comes in different thicknesses. Most of them are self-adhesive, so you don't need any other tools for installation. They are attached to the inner edge of the door leaf or stuck into the door rebate. Sealing tapes made of rubber or foam are suitable for gaps between one and 5 millimetres, depending on the window. Hollow profile rubber seals are suitable for larger gaps. Draught stoppers to be glued or screwed to the underside of the door also keep the heat where it should be.

Leaky windows and doors cause high energy loss. Outdated models are particularly responsible for this. The U-value indicates how thermally insulating glazing is. It tells you how much heat is lost through a window. The following applies: the lower the U-value, the more heat-insulating the window. For understanding: The U-value, which is the reference value, is 1.3 W/(m2K). The U-value of the first heat-insulating windows from the 1970s was 3 W/(m2K). Most windows and doors installed before 1995 should be replaced as a matter of principle. They no longer meet today's thermal insulation and energy efficiency standards. In recent years, windows and doors have undergone enormous technical development. Today, almost all windows are double or triple glazed. They also offer increased sound insulation. Thanks to special devices in the frame, today's windows and doors are even burglar-proof.

Another advantage: additional functions such as integrated insect protection in the window and door frame can be considered before installation. The choice of material also plays a role, as each material has special properties. Wood is naturally heat-insulating, but requires regular maintenance. Aluminium is very robust and easy to maintain. Plastic is just as durable and offers a variety of surface colours.

Replacing windows and doors always means high investment costs at first. However, the expenditure is worth it in the long run. Leaky windows and doors can cause energy loss of up to 40 percent. Warm room air can escape through leaky windows and be lost unused - even if warm air only escapes from one room to another. Tip: If you want to prevent this and at the same time don't want to do without aesthetic sliding doors, go for tightly closing sliding doors such as Planeo Air Silent.
Another advantage: additional functions such as integrated insect protection in the window and door frame can be considered before installation. The choice of material also plays a role, as each material has special properties. Wood is naturally heat-insulating, but requires regular maintenance. Aluminium is very robust and easy to maintain. Plastic is just as durable and offers a variety of surface colours.

The most effective way to ventilate is to ventilate intermittently. Instead of keeping the windows open for a long period of time, it is sufficient to open the windows for five to ten minutes, depending on the size of the room, and then close them again immediately. A few minutes are enough to completely renew the air in the room.

Only closed rooms allow no warm air to escape. To heat effectively, doors can be equipped with automatic door openers. The door thus closes again and again by itself and keeps warm air in the rooms.