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A solar combisystem is a solar heating system that provides both space heating and hot water from a common array of solar thermal collectors, normally linked to an auxiliary non-solar heat source. Solar combisystems may range in size from those installed in individual properties to those serving several in a block heating scheme. Those serving larger groups of properties via district heating tend to be called central solar heating schemes. Image File history File links Sustainable_development. ... Solar heating is a style of building construction which uses the energy of sunshine to heat a structure. ... Space heating is the heating of a space, usually enclosed, such as a house or room. ... A trio of propane water heaters. ... A solar heater A laundromat in California with solar hot water panels on the roof. ... District heating pipe in Tübingen, Germany District heating (less commonly called teleheating) is a system for distributing heat generated in a centralized location for residential and commercial heating requirements. ... Central solar heating is the provision of central heating and hot water from solar energy by a system in which the water is heated centrally by arrays of solar thermal collectors (central solar heating plants - CSHPs) and distributed through district heating pipe networks (or block heating systems in the case...

A large number of different types of solar combisystems are produced - over 20 were identified in the first international survey, conducted as part of IEA Task 14 in 1997. The systems on the market in a particular country may be more restricted, however, as different systems have tended to evolve in different countries. Prior to the 1990s such systems tended to be custom-built for each property. Since then commercialised packages have developed and are now generally used. IEA Logo Map of members The International Energy Agency (IEA, or AIE in Romance languages) is a Paris-based intergovernmental organization founded by the Organisation for Economic Co-operation and Development (OECD) in 1974 in the wake of the oil crisis. ... For the band, see 1997 (band). ...

Depending on the size of the combisystem installed, the annual space heating contribution can range from 10% to 60% or more in ultra-low energy Passivhaus type buildings; even up to up to 100% where a large seasonal thermal store is used. The remaining heat requirement is supplied by one or more auxiliary sources in order to maintain the heat supply once the solar heated water is exhausted. Such auxiliary heat sources may also use other renewable energy sources. This thermogram compares a traditional building (left) to one built to the German passive house standard (right) Generically, a low-energy house is any type of house that uses less energy than a regular house. ... One of the original Passive Houses at Darmstadt, Germany One of the original Passive Houses at Darmstadt The term Passive house (Passivhaus in German) refers to the rigorous, voluntary, Passivhaus standard for energy use in buildings. ... A seasonal thermal store (also known as a seasonal heat store or inter-seasonal thermal store) is a store designed to retain heat deposited during the hot summer months for use during colder winter weather. ... Renewable energy effectively utilizes natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. ...

During 2001, around 50% of all the domestic solar collectors installed in Austria, Switzerland, Denmark and Norway were to supply combisystems, while in Sweden it was greater. In Germany, where the total collector area installed (900,000 m2) was much larger than in the other countries, 25% was for combisystem installations. Combisystems have also been installed in Canada since the mid 1980s. Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... The 1980s refers to the years from 1980 to 1989. ...

It has been suggested that in future combisystems might be able to incorporate absorption solar cooling in summer [1]. The absorption refrigerator is a refrigerator that utilizes a heat (e. ...

Classification

Following the work of IEA Task 26 (1998 to 2002), solar combisystems can be classified according to two main aspects; firstly by the heat storage category (the way in which water is added to and drawn from the storage tank and its effect on stratification); secondly by the auxiliary heat management category (the way in which non-solar auxiliary heaters are integrated into the system). Year 1998 (MCMXCVIII) was a common year starting on Thursday (link will display full 1998 Gregorian calendar). ... Also see: 2002 (number). ...

Maintaining stratification (the variation in water temperature from cooler at the foot of a tank to warmer at the top) is important so that the combisystem can supply hot water and space heating water at different temperatures. Water stratification occurs when water of high and low salinity (halocline), as well as cold and warm water (thermocline), forms layers that act as barriers to water mixing. ...

A solar combisystem may therefore be described as being of type B/DS, CS, etc.

Within these types, systems may be configured in many different ways. For the individual house they may – or may not – have the storage tanks, controls and auxiliary heater integrated into a single prefabricated package. In contrast, there are also large centralised systems serving a number of properties. This article or section does not cite its references or sources. ...

The simplest combisystems - the Type A - have no 'controlled storage device'. Instead they pump warm water from the solar collectors through underfloor central heating pipes embedded in the concrete floor slab. The floor slab is thickened to provide thermal mass and so that the heat from the pipes (at the bottom of the slab) is released during the evening. Underfloor heating is a form of central heating which utilizes radiant heat for indoor climate control, rather than forced air heating which relies on convection. ... Thermal mass, in the most general sense, is any mass that absorbs and holds heat. ...

Combisystem design

The size and complexity of combisystems, and the number of options available, mean that comparing design alternatives is not straightforward. Useful approximations of performance can be produced relatively easily, however accurate predictions remain difficult.

Tools for designing solar combisystems are available, varying from manufacturer's guidelines to nomograms (such as the one developed for IEA Task 26) to various computer simulation software of varying complexity and accuracy. Smith chart which shows how the complex impedance of a transmission line varies along its length This article is about the graphical devices called nomograms. ... It has been suggested that simulation software be merged into this article or section. ...

Among the software and packages are CombiSun (released free by the Task 26 team [2], which can be used for basic system sizing) and the free SHWwin (Austria, in German [3]). Other commercial systems are available.

Technologies

Solar combisystems use similar technologies to those used for solar hot water and for regular central heating and underfloor heating, as well as those used in the auxiliary systems - microgeneration technologies or otherwise. Solar hot water refers to water heated by solar energy. ... For the Grand Central Records albums, see Central Heating (Grand Central album) and Central Heating 2. ... Underfloor heating is a form of central heating which utilizes radiant heat for indoor climate control, rather than forced air heating which relies on convection. ... It has been suggested that Wind turbines (UK domestic) be merged into this article or section. ...

The element unique to combisystems is the way that these technologies are combined, and the control systems used to integrate them, plus any stratifier technology that might be employed.

Relationship to low energy building

By the end of the 20th century solar hot water systems had been capable of meeting a significant portion of domestic hot water in many climate zones. However it was only with the development of reliable low-energy building techniques in the last decades of the century that extending such systems for space heating became realistic in temperate and colder climatic zones. (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999... Solar hot water refers to water heated by solar energy. ... The Köppen Climate Classifications are the standard incriments by which geographers and climatologists classify the climate of a particular part of the world. ... Generically, a low-energy house is any type of house that uses less energy than a regular house. ... The seven climes (klima, plural klimata, meaning inclination, referring to the angle between the axis of the celestial sphere and the horizon) was a notion of dividing the Earth into zones in Classical Antiquity. ...

As heat demand reduces, the overall size and cost of the system is reduced, and the lower water temperatures typical of solar heating may be more readily used - especially when coupled with underfloor heating, but radiators no longer longer need to be grossly oversized to compensate if not. The volume occupied by the equipment also reduces, which also increases the flexibility in its location, which can be of particular importance in individual houses. Underfloor heating is a form of central heating which utilizes radiant heat for indoor climate control, rather than forced air heating which relies on convection. ...

In common with other heating systems in low-energy buildings, system performance is more sensitive to the number of occupants, room temperature and ventilation rates, when compared to regular buildings where such effects are small in relation to the higher overall energy demand.

See also

• Seasonal thermal store
• Solar heating
  • Central solar heating
• Solar thermal energy
• Renewable energy

A seasonal thermal store (also known as a seasonal heat store or inter-seasonal thermal store) is a store designed to retain heat deposited during the hot summer months for use during colder winter weather. ... Solar heating is a style of building construction which uses the energy of sunshine to heat a structure. ... Central solar heating is the provision of central heating and hot water from solar energy by a system in which the water is heated centrally by arrays of solar thermal collectors (central solar heating plants - CSHPs) and distributed through district heating pipe networks (or block heating systems in the case... Solar thermal energy is a technology for harnessing solar energy for practical applications from solar heating to electrical power generation. ... Renewable energy effectively utilizes natural resources such as sunlight, wind, tides and geothermal heat, which are naturally replenished. ...

External links

• IEA Task 26 official site
• The European Altener Programme Project: Solar Combisystems
• Solar combisystems - thinking big for a sustainable energy future (Published 2000)
• Test of Thermal Solar Systems for Hot Water and Space Heating (June 2004)
• Combisystem test reports - Mostly in German

References

• Solar Heating Systems for Houses – A Design Handbook for Solar Combisystems, James and James, ISBN 1-902916-46-8 (by the Task 26 team)