Climate-stable doors are primarily used in larger public buildings. However, there are also situations in private homes where a climate-stable functional door is the best solution. The ‘Door in Dialogue’ demonstrates
- where a climate-stable door is suitable,
- what it can do
- and why there is a ‘climate chamber’ for doors.
Perfect weather: wet and cold outside, warm and dry inside.
It’s actually quite simple: a door’s job is to separate two rooms from one another. But sometimes that ‘job’ is more difficult. This is the case when a door also separates two different climatic conditions. Take this example: in winter, the temperature in the unheated hallway of a block of flats is 3 degrees. Yet inside the warm flat, the temperature is supposed to be a constant, ‘cosy’ 20 degrees.
The problem is that, particularly in autumn and winter, every visitor brings moisture and damp into the building. Consequently, the climate on either side of the flat’s front door actually differs significantly: whilst the humidity inside is around 30 per cent, it’s over 80 per cent outside.
Significant differences in temperature and humidity can cause each door leaf to expand and warp differently. The result: the door no longer closes properly. Cracks and gaps form. In the worst-case scenario, the door no longer performs its ‘job’ properly: the two climatic conditions mix. Damp, cold and other external influences – including, for example, noise and odours – find their way through to the other side of the door. This permanently jeopardises the comfortable indoor climate.
The term ‘climate-stable door’
At GARANT, a climate-stable door is always made of wood (or a wood-based material). Wood ‘expands and contracts’ throughout the year.
However, these functional doors are not damaged by cold or damp. Instead, they remain ‘in shape’ over the long term and preserve the indoor climate. If such a door does happen to warp, this occurs within a very narrow tolerance range of just a few millimetres. Doors without climate stability cannot do this: they often warp by up to one centimetre.
There are a total of five climate classes for doors: as a specialist in interior doors, GARANT offers climate-stable room and flat entrance doors up to climate class 3. (This climate class is certified for temperatures down to 3°C and 85 per cent relative humidity.)
Climate chamber for interior doors
About every four weeks, the door to the climate chamber is opened. During this time, one side of the room is maintained at an air temperature of around 23 degrees and a relative humidity of 30 per cent. This is comparable to the indoor climate in a heated living room during winter.
On the other side of the door, the target climate is created: in climate class 3, this is around 3 degrees with a humidity of 85 per cent. This corresponds to the indoor climate in a hallway in winter.
Three doors of identical construction are tested simultaneously in the climate chamber. This ensures comparable and reliable measurement data. Fixed measurement points are used to document how the material warps. At the end of the test period, which lasts several weeks, the doors leave the climate chamber.
Such a ‘climate test’ for doors is carried out, for example, by the independent Institute for Window Technology (IFT) in Rosenheim. The test forms part of the development process. Ultimately, a door must pass the ‘climate test’ in order to be certified as climate-stable.
Tip from a door specialist: don’t rush to make a complaint about doors.
‘The air is very damp, especially in new-builds,’ says Enrico Schüller. ‘This is why interior doors usually warp visibly. However, I always advise waiting for one heating season to pass before making a complaint. This is because many doors return to their original shape as soon as the new-build has dried out.’
Climate-stable doors can also protect against noise, fire and burglary.
A climate-stable door can do even more: after all, ‘climate protection’ in the door is a prerequisite for other functions, such as sound, smoke, fire or burglary protection (‘Brochure: Expertise in Function and Design’). Such doors are primarily used in public buildings: as entrance doors to flats, in hospitals, hotels, schools, hostels, barracks and nurseries.
GARANT uses special materials to provide additional functions such as sound, smoke or fire protection. There is also a wide range of design elements available for these doors.
Incidentally, the door expert also has a climate-control door in his own home: it separates the utility room – which houses the heating system, tumble dryer and top-hung window – from the rest of the house.
Further reading:
One of our partners for the climate chamber is IFT Rosenheim. www.ift-rosenheim.de
In brief: Door expert Enrico Schüller
After completing his A-levels, Enrico Schüller first undertook an apprenticeship as a woodworking technician. He then went on to study wood technology. With his diploma in hand, he entered the furniture industry and soon joined GARANT. As a member of the GARANT development department, he designs new doors. Together with his colleagues, Enrico Schüller not only designs the structure of a door leaf on the computer and produces drawings. He also plans the use of raw materials and is always on the lookout for new materials.
In his spare time, too, this door expert enjoys working with wood – especially when it comes to building high-quality furniture for his family. His children (aged 9 and 4) are allowed to join in, but they quickly lose interest.