Obiettivo A novel design of a glazed roof space, solar energy collector is demonstrated on 15 dwellings in the Milton Keynes Energy Park England. The system provides space heating either alone or as a preheat to an auxiliary gas fired warm air heating system. The fan and associated duct work, through which the warmed air is conveyed from the roof space collector, are existing parts of the auxiliary system. By integration of the 'solar' components into the conventional system and via optimal design for installation in new dwellings, low initial and running costs are expected.The first preliminary results concern the overheating of the roof space solar collector in summertime. It is necessary to extract the hot air to keep the temperature within acceptable limits. The option of a forced cooling with ventilators was abandoned for safety, reliability and energy reasons. In consequence, a totally passive system is applied with 'memory metal' springs, which open some flaps if the temperature exceeds 50 deg. C. As an additional precaution, the floor in the roof space is painted white to reflect the solar gains at high summer sun angles (with some reduction of performance in wintertime).The contribution of the collectors to space heating load is being assessed; this depends largely upon the heating regime adopted by the occupants. Monitoring and analysis continues.A roof space solar energy collector is essentially a pitched roof which is partially or fully glazed on its southerly aspect. The attic space is frequently painted matt black internally to enhance the collection of solar energy. Thus the system is sometimes referred to, somewhat inelegantly, as a "black attic". Solar heated air from the roof space collector is conveyed by an automatically controlled fan via a duct either directly into the living space or as a pre-heated supply to a warm air space heating system. The roof space collector is replenished with air either from within the dwelling or from outside ambient environment. The fan and associated duct work, through which the warmed air is conveyed from the roof space collector, are existing parts of a gas-fired warm air space heating system.When the air from the roof space solar energy collector is at a lower temperature than the set level of the room thermostat, the air stream emerging from the roof space collector is a pre-heated supply to the gas fired auxiliary system. A single fully integrated wall mounted control unit will actuate both the gas fired auxiliary warm air heating system and the roof space collector.A roof space collector involves the passive collection and active distribution of solar heat and is thus generically a hybrid solar energy system. Warmth is stored within the structural elements of the roof space collector at night. Ventilation is employed to prevent overheating in high summer.1. During daytime conditions when the temperature of the roof space collector is above that of the building, a thermostatically controlled fan continually takes air from the buildings. This air is passed through the roof space collector, is warmed and returned to the building. This mode is suitable for a dwelling that is occupied during the day.2. During the day the roof space collector rises in temperature as solar energy is collected and no forced circulation of air occurs through the system. In the late afternoon the stored heat is harnessed. Warm air is conveyed from the roof space collector by a fan. The resplenished air to the attic may be supplied from either inside or outside the building. This mode is most appropriate when the building is unoccupied during the day. The system has a low initial capital cost as its physical construction of a roof space collector does not differ greatly from that of a conventional pitched roof.On each dwelling the system will provide 10.4 GJ per annum. This will constitute 49% of the total annual space heating requirements of each dwelling. The conversion of solar energy to useful heat is accomplished with a 10.6% annual efficiency. Programma(i) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Argomento(i) 7.2 - THERMAL Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore MILTON KEYNES DEVELOPMENT CORPORATION Contributo UE Nessun dato Indirizzo AVEBURY BOULEVARD 502 MK9 3HS MILTON Regno Unito Mostra sulla mappa Costo totale Nessun dato