Cel A new residential area of 27 houses plus a communal building with a total estimated heat demand of 360 000 Kwh/a should be totally supplied by renewable energy sources (40% solar and 60% wood boiler).A solid wood boiler had to be replaced since it achieved only 35 % of expected efficiency: a supplementary 54 KWh electric heating boiler was installed. Even then it was difficult to produce sufficient heat. The total bill for heating expenses was +/- 3 times greater than expected and more expensive than the use of gas. Eventually, to improve efficiency it became a choice between connection to the municipal district heating system and installation of a gas boiler (later supplemented with a hot gas cooler for condensation), and the latter won. An atmospheric gas boiler (128 KWh/h) was put into operation and has been performing satisfactorily at 80 % efficiency.Although the solar collection plant functioned satisfactorily, yield ranged between 38% and 50% of the expected annual contribution of 150,000 KWh. This was improved with the addition of antifreeze liquid (caused by leaking venting valves). These were manually closed and until a replacement was found, manual venting took place. And, in order to achieve improved, more accurate operation, the original start/stop sensors were supplemented with sensors next to the heat exchangers. However, the solar heating system can only contribute to the heating after several days of continuous sunlight. To make the best of this a change was made whereby the solar collecting system heats return water via an extra heat exchanger.Following these changes, under normal circumstances the plant is expected to deliver 75,000 KWh/y. or 20% of the community's total heating requirement.The community area consists of 27 two storey low energy houses (12 individual and 15 terrace, of 80 m2 to 130 m2) and one communal building of 650 m2. All houses have two floors and south facing roofs of 45 degrees. The communal building roof and 15 of the 27 houses are equipped with solar collectors. The number of north facing windows has been kept to a minimum.Internal walls are constructed in heavy materials to capture heat from the sun, people and light. The houses are insulated with mineral wool type A: 30 cm on the roof, 20 cm in the walls and 35 cm Leca in the floors. Windows are triple glazed. The solar collectors are connected to two concrete 28 m3 and 45 m3 storage tanks situated under the communal building. All components connected to the energy supply system such as boilers, heat exchangers, tanks, pumps, valves and measuring equipment are situated in the communal building plant room. Heat production for space and hot water heating is achieved by solar collectors (540m2) supplemented by gas and electric boilers. Total solar collector area is 180 m2 for the communal building and 360 m2 for 15 of the 27 houses. Gas boiler output is 128 KWh with 54 KWh from the stand-by electric boiler. Heat distribution is by heat exchanger into underground pipes, combining boiler plant heat from the 500 l. buffer tank. In the communal building domestic hot water may be preheated in one of two storage tanks (each of which is equipped with a 200 l. storage tank with sensor), prior to storage in a 650 l. hot water tank (temperature adjusted by Danfoss thermostat valve).Insulated pipes distribute the heat to each house which is then used for floor heating in the bathrooms and by thermostatically controlled radiators in the other rooms. The communal building is heated by radiators with a thermostat in the flow pipe. Expansion of the liquid in the piping system is by pressure expansion tanks and safety valves. A small expansion storage tank is locally placed at theelectric and gas boilers. Each expansion storage tank is fitted with a safety valve, and air escape. Program(-y) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Temat(-y) 3.1 - THERMAL Zaproszenie do składania wniosków Data not available System finansowania DEM - Demonstration contracts Koordynator BOFAELLESKABET SOL OG VIND Wkład UE Brak danych Adres BYAGERVEJ 217 8330 BEDER Dania Zobacz na mapie Koszt całkowity Brak danych
