Bedding under the Microscope!
The climate under the duvet and the properties of the mattress represent the most important criteria for human comfort while sleeping.
The interaction between human and material characteristics during the creation of the bed hollow climate is determined by the laws of heat regulation for humans.
The microclimate of the bed hollow is crucially influenced by the climatic situation in the bedroom and the design of the bedding.
As part of a scientific study conducted by the University of Kiel in 1992, the issue of what impact the bedding has on the microclimate of the bed hollow was investigated in particular.
The insulating effect of a duvet depends primarily on the
- the filling material (e.g. down and feathers)
- the filling quantity (in g)
- the type of stitching (e.g. processing of the inner webs, geometry of the stitching)
- the billowing capacity (i.e. capacity of the filling to bind the air, as this cushion of air is extremely important for the insulating capacity of the bedding
- the adaptability (i.e. to what extent the duvet has the ability to adapt to the shape of the sleeper and his or her movements).
As part of a major study with respondents, 14 duvets were investigated, which reflect the supply of bedding currently available on the market, both with regard to the materials used and to the filling quantity (e.g. fillings made of animal hair, silk, synthetics, feathers and down).
During a test with comparable bedding, the focus of the study was on whether or not the assertion is true that there is heat accumulation under featherbeds.
Heat accumulation is characterised by an increase in the core temperature of a person, so that the sleeper no longer feels comfortable in his bed, i.e. the cover was unable to compensate for the temperature in a suitable manner. The tests conducted with different duvets were able to clearly show, however, that inappropriately high temperatures in the bed hollow do not occur under normal bedroom conditions for any filling material, and therefore, also not for featherbeds.
Bedding filled with down and feathers is capable of being able to achieve a high degree of thermal insulation with a low filling weight. This comparatively low filling weight is an extremely significant factor for sleeping comfort.
Another important criterion for the climate in the bed hollow is the humidity. Here too, it has been shown, that bedding filled with feather and down is very capable of absorbing and transmitting the body's humidity so that it is not perceived by the sleeper as being uncomfortable.
For these studies three groups of candidates, namely persons with mild, medium and strong perspiration, were selected, so that the whole spectrum of the requirements of a person for a duvet were able to be covered.
During the course of these sleep studies it became clear that it is very important that a duvet not only has an insulating, moisture-absorbing, and temperature-compensating effect, but also is able to sufficiently adapt to shape of the body. As every person frequently changes the position in which he sleeps during the night, thus subconsciously leading to a "ventilating effect" on the body in the bed, it is important that the duvet is able to optimally adapt after each change in position, so that no cold air is allowed to flow into the bed hollow by the formation of so-called tunnels, for example.
Bedding filled with feathers and down can be tailor-made with regard to the needs of the sleeper. Here the preferred room temperature, the radiation of heat from the body, the predisposition to perspire and the movement behaviour while asleep play a role. By varying the size of the duvet, the filling weight and the stitching, for example, the duvet can be "customised".
When buying bedding, not only the season, the ambient temperature and the bedroom temperature are crucial, but also the requirements of the respective sleeper concerning the duvet. People who freeze easily, can, for example, find the optimal bedding having a comfortable down filling, processed with inner stitching for winter duvet and a light down duvet, processed, for example, with dot stitching in the summer.
There is one point to remember. The comfort size of 155 x 220 cm for the duvet is recommended in every case.