In the following is shown highlights from a solar low energy retrofit project made as a part of urban renewal at the Hedebygade housing block at Vesterbro, Copenhagen.
Photo from the inner yard of the Hedebygade housing block before the solar low energy project was made.
The housing block in Sundevedsgade 14, Tøndergade 1 before the rehabilitation.
The following 3 projects has been realised in cooperation with the SBS Urban Renewal Company with extra support form the Danish Energy Agency and the EU-Thermie programme (European Green Cities).
Highlights (Tøndergade 3-3A):
# Additional insulation and low-energy windows.
# Central placing of the radiators.
# Central heat recovery systems.
# Two central heat recovery units, placed in the attic, covering 10 apartments each. Heat surfaces that give extra heat to the ventilation air.
# Building integrated amorphous PV-modules from Fortum in the facade.
# The living rooms facing the courtyard have a 6 m² heated glazed patio each. The window parapets are covered with 60 m² amorphous PV-modules. The PV-modules are utilised in a hybrid solution where the ventilation air is preheated behind the PV-modules, which also has the effect that the cooled PV-modules get a higher yield.
Building integrated amorphous PV-modules (from Fortum) in Tøndergade 3, 3A, which are used to preheat the ventilation air. Architect is Jørgen Rosenkilde.
Highlights (Sundevedsgade 26-28)
# PV-modules. 60 m² mains connected crystalline PV-modules from Gaia Solar have been mounted on the two original stair turrets. Preheating of the air in the stair turrets cools the back of the PV-modules and in this way the transmission loss between the stairs and the apartments is reduced.
# Solar heating system. On the roof there is a solar heating system from Batec Solar Heating that heats the domestic hot water. The total area is 35 m².
# Heat recovery. In the attic there are two high efficient counterflow heat recovery units from TermoVex Denmark, which covers 10 apartments each.
# Central placing of radiators gives saving on investment costs.
# Double windows with hard covering.
# Solar energy optimised sunspaces with overheating protection
# Heat recovery of the ventilation air has in this way reduced the heat loss of approx. 20 kW; equal to approx. 20 W per m² heated area.
# 82 DKK/m² has been saved by use of a solution with centrally placed versus conventionally placed radiators. In a 70 m² apartment this is equal to a total saving of the investments of 5,700 DKK, which are primary coming from the use of centrally placed riser pipes.
Figure 3.49. Sundevedsgade 26-28. Facade facing the courtyard. Here is seen the solar collector on the roof and the PV-modules on the stair turrets. Architect is the Architect group Copenhagen.
Highlights (Sundevedsgade 14/Tøndergade 1)
The project includes the rehabilitation of 20 apartments. The following energy saving measures are included in the project:
# Air solar collector. A 19 m² air solar collector has been mounted on the roof, and heats a central storage tank in the basement, which is also connected to the district heating system.
# A new solar wall design with an integrated heat recovery unit that is also connected to the district heating system is used for 12 apartments. The only 25 cm thick counter flow solar wall has been built with frosted glass and PV-modules as covering coat. The heat recovery unit has been placed inside the solar wall. This innovative unit from TermoVex Denmark contains both the counterflow heat recovery unit, sound absorber and ventilation fans. The complete heat recovery system is high efficient and has a very low electricity consumption. These systems form part of the EU/Joule project PV-VENT together with the PV-modules. A built-in damper in the solar wall that secures against too high temperatures.
# Ventilation with heat recovery for eight apartments. The corner apartments cannot be connected to a solar wall and individual counter flow heat recovery units with 85% efficiency have therefore been placed here also as individual systems. The ventilation systems in these apartments have been made as real air heating systems by means of heating surfaces that are heated by district heating. There is also a traditional but centrally placed radiator system to cover peak load.
# PV-modules. The PV-modules form part of the solar wall and the produced electricity is used directly in the heat recovery unit by help of a so-called PV-mixer. There is approx. 1 m² PV-modules per apartment.
# Water heat exchangers. The heating is supplied from the central storage tank in the basement, which is partly supplied with district heating and partly with heat from the air solar collector. The heat is in this way supplied to the apartments for both room heating and domestic hot water via only one duct, which reduces the heat loss. The heating of the water takes place via individual domestic hot water heat exchangers that also secure against problems with bacteria.
# South oriented sun-protected sunspaces for each apartment and improved daylight function.
Figure 3.50. The housing block in Sundevedsgade 14, Tøndergade 1 after the rehabilitation.
A counter flow heat recovery unit from Termovex Denmark with built-in heat exchanger, sound absorber and ventilation fans fit into the solar wall and the used solar collector in connection with urban renewal of the building in Sundevedsgade 14, Tøndergade 1.
Viktoriagade 10B at Vesterbro
In the summer and autumn of 1998 a large PV-system was erected on old business premises at Vesterbro in Copenhagen in cooperation with Cenergia, SolarVent and the urban renewal consultant Bjarne Lundt and the urban renewal company SBS and with funding from the EU/Thermie programme.
On the south facing gable of the building a total of 8.6 kWp crystalline PV-modules from the company Gaia Solar have been installed, which is equal to approx. 86 m² PV-modules. The PV-modules are mounted with an aluminium frame system developed for this purpose, which is easy to mount and at the same time is made so the PV-modules can preheat ventilation air.