Winter garden
A winter garden is an extension to a building or an independent structure, the roof and side walls of which are largely made of glass . The properly constructed conservatory uses the greenhouse effect (not to be confused with the atmospheric greenhouse effect ) instead of conventional heating techniques for achieving an ambient temperature that allows the winter of suitable plants. The passive use of solar energy leads to a noticeable heating of the indoor air compared to the outdoor air, even with little direct sunlight or scattered light. In order to optimize this effect, a large part of the glass facade (in the northern hemisphere) has to face south.
Sometimes the term is used in multi-storey buildings or in the housing industry to denote a glazed, not artificially heated part of the apartment, e.g. B. a subsequently glazed balcony , which can then come close to the bay window in terms of terminology , or a subsequently glazed loggia , although here only one side, flush with the facade, is made of glass.
history
The winter garden as we know it today has its origins in the stately orangeries , palm houses and the English conservatory . In the 18th century, numerous luxurious, private winter gardens were built in England as extensions to houses that were only affordable for the wealthy. The forerunners of the winter garden go back to antiquity, when buildings for the cultivation of plants and fruits from the overseas territories of the colonial powers were also used.
The winter garden experienced lasting stylistic expressions in the Victorian era, when orangeries enjoyed a rapidly growing popularity everywhere. The glass - steel constructions were richly decorated in the style of the time and became part of an architectural form that formed an epoch that spread across the entire European continent. Glazed greenhouses and palm houses became a characteristic feature of botanical gardens and bear witness to the era that gave architecture lasting impulses.
Since then, the winter gardens have been used for the first time as spaces where people can hang out and communicate with one another. They were therefore no longer just exhibition rooms for green plants, but equipped with tables, chairs and benches, giving people a completely new lifestyle and lifestyle.
Since the 1880s, winter gardens came into fashion in Germany as part of town houses and holiday pensions. Up until the 1930s, they were extremely popular in Germany in their classic architectural style. The winter gardens of our day, on the other hand, are less an expression of nostalgic reconsideration, but a move towards new forms of architecture. As a result of the 1973 and 1979/80 oil crises , increased ecological awareness and other factors, sunlight was rediscovered as a source of energy and thus the building material glass was also rediscovered in architecture.
In the course of the development, the living room winter garden emerged, which expanded the living space.
Heat balance
If the winter garden is heated on days without solar gains (no sunshine), the heat losses are significantly greater than with conventional walls and require around three to four times the heating output. The high solar gains from solar radiation and scattered light lead to a drastic reduction in heating days or heating hours / heating day. A considerable part can be used to reduce the heating output for the rooms behind, so that the annually required heating energy with full use as living space in relation to the entire usable area (including the living room conservatory) depends on the specific geometry and location changes. If the winter garden is not used as living space when there is no solar gain (room temperature <19 ° C), it should be separated from the house by doors. Then it acts as a buffer zone that saves heating energy.
Low-temperature heating strips or extensive underfloor heating in a winter garden can also be operated without wasting energy. But only if these heating elements serve as the last link in a series connection of the heating return of a condensing boiler to lower the temperature of the return water and consequently the temperature of the flue gas even further than is possible without this "heat exchanger". The usually prescribed for old buildings radiators as "heater" in the living areas must in fact often be operated with lead-high temperature, can not be used whereby the condensing effect. With additional low-temperature heating systems, only the latent heat of condensation or residual energy of the flue gas is used, which is otherwise uselessly blown through the chimney (if no full condensing boiler or air-flue gas system is used). However, the flow temperature must not then be increased so that the winter garden is also heated to the same "room temperature" as the rest of the apartment, but this type of winter garden heating may only use the unused calorific value and only serves as frost protection. The actual winter garden heating should be done by the sun and the plants in the winter garden should be selected accordingly.
To improve the heat storage, a sunlit wall can be designed as a solid storage wall (for example made of unfired clay bricks) or the floor covering with terracotta tiles.
Overheating or draft problems can be avoided by a so-called "hypo-exchanger" system , in which the warm air in the winter garden evaporates and the moist air that has risen is sucked off at the highest point of the winter garden and is passed through hypocaust pipes on the colder ground, whereupon the water vapor condenses there and the released heat of condensation is given off to the ground.
Types of winter gardens
A distinction is made between three types of winter gardens in terms of thermal technology:
- A warm winter garden can be used for living all year round and is also called a living room winter garden (room temperature> 19 ° C). There is a year-round climate that makes a pleasant stay possible. It is also suitable for tropical plants with higher demands. The requirements of the Energy Saving Ordinance for residential buildings apply here.
- A moderately warm winter garden is a cool winter garden that is heated to 12–19 ° C during the heating period. The Energy Saving Ordinance has lower requirements for the thermal insulation properties of the glass roof and the side elements than for the living room conservatory.
- A cold winter garden is a glass extension that has little or no heating. If it is used to overwinter non-winter-hardy plants, a corresponding minimum temperature must be ensured. The use as living space is limited to the warmer season, accordingly the name summer garden also exists in the region .
Aspects of construction planning
Eight topics are particularly important for the planning and execution of a winter garden:
- a suitable frame construction (statics including consideration of wind and snow loads according to DIN 1055-4 and 5, thermal separation, observance of statics, thermal insulation, water vapor diffusion and water flow at the building connections), DIN 4102 fire behavior of building materials and components
- adequate ventilation
- a shade
- Glazing with suitable installation and glazing profiles according to the substructure (wood or steel) with sufficient watertightness and resistance to wind loads.
- Optimized functions according to the purpose of use and the location of the property (load absorption, if necessary heat protection, observance of overhead glazing according to TRLV - soon to DIN 18008-, if necessary sun protection glass in the roof, if necessary sound insulation, if necessary "self-cleaning" effects, if necessary fall protection according to TRAV - soon DIN 18008, possibly safety glass or optimized light panels )
- a heater that is adequately dimensioned for the required peak load and located in the coldest places, which at the same time provides the necessary air circulation ("air cylinder").
- a floor structure dimensioned according to the intended use and, in the case of heated winter gardens, thermally insulated, with appropriate thermal separation of the inner floor and a barrier against moisture rising from the floor. - DIN 18195 building waterproofing
- a gutter and downpipe heating, because due to the significantly improved thermal insulation, the heat loss is no longer sufficient to thaw the gutter and downpipes and thus avert blockages caused by ice and snow. On sunny days, otherwise accumulating condensation water can penetrate into the construction or the interior of the winter garden, which is usually only designed to be tight for non-pressing, draining water.
Glazing of winter gardens
There are various ways of assembling the glass panes on conservatory roofs. In the aluminum, steel and plastic conservatory systems that have been optimized in the last two decades, especially with regard to thermal separation, the glass bracket is an integral part of the load-bearing rafters, wall connections and eaves support profiles. In wooden winter gardens, aluminum support profiles or plastic thermal support profiles are mostly used today. These glazing profiles are available as complete systems and, in addition to the glass holder, serve to protect the wooden structure from weather. Another variant for the glass supports are self-adhesive solid rubber supports ( EPDM ) with grooves. These are available in different widths and strengths. They are placed on the wooden substructure and are easy to work with. There are also systems that can thermally separate the cold outside from the warm inside of the winter garden.
For the glazing of the side walls, fully glazed windows, French doors, sliding and folding systems from a specialized production facility are usually used. However, mullion and transom constructions with the glass brackets belonging to these systems are also used in handcrafted or large-scale production.
Sun protection and ventilation system
In order for a winter garden to be usable all year round, it must not only have sun protection, but also sun protection glass, as well as an automatic ventilation system (possibly with a heat exchanger to save energy). If it is oriented directly to the south, a deciduous tree (chestnut, pear tree, etc.), which has leaves in summer and provides shade, but largely lets the light through in winter, can be at a sufficient distance from a few, especially in locations that are already quite warm Meters, reduce the build-up of heat in summer without taking away a lot of sunlight in winter. Similarly, large plants (e.g. small trees) in pots can be placed on the outside in pots in the summer when it is very hot (at least if the winter garden is at ground level).
An automatically controlled winter garden ventilation prevents overheating in summer and moisture problems and their consequences in winter, such as moisture condensation and mold growth , even in the absence of users .
Victorian conservatory style
A special style of the winter garden are Victorian winter gardens. Shapes and decorations from Queen Victoria's England shape the impression of these winter gardens.
Historical
The orangery buildings are an early form of the winter garden . They were and are partly designed as a lean -to house.
Conservatory planting
A winter garden is not a greenhouse (which sometimes puts more emphasis on the high light permeability of the glass than on the insulation effect). There are usually wide temperature fluctuations in a winter garden, which not all plants can tolerate. In order to thrive, many tropical plants require higher humidity, longer days of sunshine or additional exposure in winter, minimum winter temperatures, maximum temperatures, and optimal temperatures in general, which have little in common with a "living environment". Necessary cooling in the event of overheating can lead to unpleasant drafts. Well-proven plants are, for example, citrus, camellias and euphorbias , which can also tolerate weak frosts. But you can also grow vegetables in the winter garden.
Individual evidence
- ↑ The difference between a summer garden and a winter garden. In: mein district.at. April 21, 2016, accessed May 11, 2018 .
- ↑ See: Wolfgang Isenmann, Ralf Adam, Günter Mersson: Moisture phenomena in inhabited buildings . Publishing house for economy and administration, Essen 2008, ISBN 978-3-8028-0560-8
literature
- Wolfgang Naumer: Build and modernize in an energy-saving way . Haufe, Munich 2008, ISBN 978-3-448-08599-0
- Günther Simon: The energy-optimized house. Planning manual with project examples. EnEV 2009 already incorporated . Bauwerk-Verlag, Berlin 2008, ISBN 978-3-89932-135-7
Web links
- Link catalog on the topic of winter garden at curlie.org (formerly DMOZ )