Save energy thanks to window sealing

Old windows in particular often no longer seal as desired. This is particularly noticeable in the cold season, when the cool air from outside is drawn inside. This causes the rooms to cool down more quickly and more heating is needed.

In addition, moisture penetrates, which in the long run can lead to mould growth on the window frame and walls.

But just because a window leaks, it does not have to be completely replaced. Often, the seals can be brought up to date themselves with simple means.

Locate leaks

Before the leaking windows can be sealed, it is necessary to find out where they are leaking in the first place.

This can easily be done with the help of a burning candle or a lighter by holding it against the closed window and watching how the flame behaves.

Seals are often porous after many years of use and allow air to pass through small holes.

Some gaskets can also be torn off directly at the first attempt if the adhesive edges no longer hold properly. If this is the case, the seal should be replaced.

It is also important to check not only the seals at the edge of the window, but also the glass surrounds. These seals can also shrink and become porous or brittle.

However, if the window sash has warped, it should be readjusted by a carpenter, especially in older houses. With modern windows, on the other hand, it can already help if the fittings are oiled and readjusted.

Which window seal is the right one?

There are various possibilities and materials for sealing the corresponding components. Each variant has its own advantages, so you should find out exactly which method suits which project before starting work. Generally, one decides between:

• Self-adhesive sealing tapes
• Foam and rubber seals
• Silicone
• Acrylic

Seals on wooden and aluminium windows can easily be renewed with self-adhesive sealing tapes. Foam and rubber seals, on the other hand, are suitable for sealing gaps in the frame.

Silicone and acrylic are also a possibility for sealing windows: The question here is whether the element to be sealed comes into contact with water or not. The appropriate sealant can therefore be selected individually.

No other seals may be glued onto prefabricated rubber seals of a plastic window. Professional advice is required here.

Once the leak has been identified, the old seals and adhesive residues must be removed before a new seal can be applied. Once all old residues have been removed, clean the substrate thoroughly and allow it to dry well, as sealants hold very poorly or not at all on damp substrates.

The place where the new sealing tape is to be applied must be precisely measured and the tape adjusted to the appropriate length. The exact fitting ensures that your window seals airtight again.

Mobile air conditioners discharge their exhaust air via a hose. In order for them to cool, the warm air must be discharged to the outside. This is usually done by hanging the exhaust hose out of a window, as most users do not make a hole through the wall of the house for this purpose.

The air conditioner should therefore be placed close to a window so that the exhaust air hose can be placed out of the window.

However, to ensure optimum cooling, window sealing is additionally necessary in most cases.

If the hose has to be routed outside through a window (or a door), it is open. This gives the warm outside air a chance to flow into the room. Since this naturally counteracts the effect of the mobile air conditioner, it is important to prevent the inflow of warm outside air. And it is precisely for this purpose that special seals are available:

• For top-hung and roof windows
• For sliding windows and doors

A window seal ensures that the warm exhaust air gets out through the hose, but no warm outside air can get back in. The mobile air conditioner can be used optimally and achieves a better cooling effect with the help of the seal.

The ideal room temperature is desirable not only for reasons of well-being, but also for health reasons.

Correctly seal top-hung windows and skylights

Most air conditioning hoses are hung outside through a hinged window. For this purpose, there are window sealing systems made of a special foil, which offer the possibility to hang the hose outside through a precisely fitting opening. In this way, only warm exhaust air is conducted to the outside, but no warm air is conducted to the inside.

The installation of these window seals is usually very simple, as most have Velcro on the edges. The counterparts are self-adhesive and are attached to the window and window frame.

The foil can now simply be attached and, if desired, detached again. A zip is sewn into the film itself, which can then be opened so far that the hose of the air conditioner fits through without any problems.

The film also has a few positive side effects:

• Insect screen
• Pinch protection

This type of window sealing is perfect for open and tilted windows as well as for slanted roof windows. Depending on the manufacturer, the film must be gathered in or completely removed to close the window.

However, there are also models where only the hose has to be removed and the window seal can remain hanging just as it is.

The film usually has special properties to meet all possible requirements:

• Translucent
• Water repellent
• Hard-wearing
• Machine washable

The window seals come in different sizes, so they are also suitable for larger windows. And if the air conditioner is a two-hose model, a system with multiple zips can be used so that two openings are possible.

Sealing systems for sliding windows and doors

For sliding windows and doors, the above-mentioned sealing films are not an adequate solution. Special sliding seals are available for this purpose, but they fulfil exactly the same purpose: They prevent warm outside air from entering and thus help to better achieve the desired room temperature and save energy at the same time.

The sealing systems are suitable for both vertically and horizontally closing sliding windows and doors.

Sliding seals are quite simply fixed in the window gap and can be adjusted to different lengths. The panels are usually made of PVC, can be slid and are easily fixed with small screws. There is an opening to which the exhaust hose of the mobile air conditioner is attached by means of a two-part ring.

When buying, make sure that the dimensions of the hose correspond to the dimensions of the opening, as this cannot be variably adjusted like the zip openings.

Window seals are important helpers in every house and flat.

In most cases, they are easy to handle and can be applied without professional help, whether it is new seals on the window or a window seal for the mobile air conditioner.

They provide sustainable support so that the temperature in the room can easily be kept at a comfortable level. This saves energy and prevents unnecessarily high electricity and heating costs. Whether it's porous seals or a hole for the air conditioning exhaust hose, window sealing is always a good choice.