Research project , Group project Supervisors: M. Sc. Daniele Santucci Technical University of Munich - TUM, 2014
energy-retrofitting of the herz-jesu church in munich
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Solar altitude
21/12/2013 Latitude [N]: 48.15o Longitute [E]: 11.52o
21/06/2013 Latitude [N]: 48.15o Longitude [E]: 11.52o
SUMMER FACADE
Natural ventilation (XPS) Rigid Foam Insulation
Wood frame construction wth internal shading system (maple lamella)
g-value: ca. 20% – 32% solar Control glass variable printed facade
16 mm laminated glas VSG 10 mm toughened glas ESG with low iron oxide content glas Insulated glazing (IG) (double-pane)
Natural ventilation
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Automatic tiltable windows
The Herz-Jesu church is located in Munich and was designed by Allmann Sattler Wappner Architects. The building comprises two different cubes, which are set into one another. The outer glass cube (16x21x48 m) envelopes an inner shell of more than 2.000 maple lamella. Due to the contrasting material properties of these two cubes, different colours and intensities of light shine into the church. The arrangement of the vertical lamella gradually increases the brightness of light towards the altar. At the same time, the opaque glazing prevents views into the chancel from the outside. The entrance of the building is charaterised by large, intensive blue doors, which are opened only on special holidays. The glas facade is made of doublepane solar control glass. A part of the solar radiation is reflected; another escapes into the internal space and another is absorbed from the glasa and re-emitted als heat in the space. Automatic tiltable windows, along the facade and on the top of the building, allow for natural ventilation. Underfloor convectors, along tha facade in front of the tiltable windows, heat or cool the outside air before entering into the internal space. Because of the huge glass facade, cold air drop is a major problem affecting thermal comfort, especially during the coldest months of the year.
WINTER FACADE
Natural ventilation (XPS) Rigid Foam Insulation
Cold air drop
Wood frame construction wth internal shading system (mapla lamella)
g-value: ca. 20% – 32% solar Control glass variable printed facade Heat losses
16 mm laminated glas VSG 10 mm toughened glas ESG with low iron oxide content glas Insulated glazing (IG) (double-pane)
Cold air drop
Natural ventilation when external temp.<internal temp.
Automatic tiltable windows
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Floor cooling
Underfloor heating
Chilled ceiling
Underground horizontal air ducts Heat exchanger
Heat exchanger
Ground-water heat pump
Ground-water heat pump
Chilled ceiling
Floor cooling
SUMMER 6
Primary energy demand
A heat pump provides heating during winter by extracting heat from groundwater and transferring it into the building. A heat exchanger is in contact with the groundwater to extract or dissipate heat. In the summer, the process can be reversed so the heat pump extracts heat from the building and transfers it to the groundwater. Transferring heat to a cooler space takes less energy, so the cooling efficiency of the heat pump gains benefits from the lower groundwater temperature. Groundwater has a stable temperature of 8째C to 12째C during the whole year.
Cooling
Heating
Lighting
Floor heating
Under-floor convectos along the facade
WINTER 7
“Full operation”
“Basic operation”
Temperature measurements Date: 12/12/2013 Time: 15:00-16:00 am
The church operates ~3400 hours per year. However, there
OPTIMIZATION PROPOSAL
are two different operation types. The “Basic operation”, when the church is open for visitors but no ceremony
The optimization proposal focuses on enhancing natural
takes place and the “Full operation”, when a ceremony or
ventilation. Windows open only when the outside air
concert takes place. The desirable operative temperature
temperature is lower than the operative temperature
during “Basis operation” is ~22 °C under summer
inside the church. When the outside air temperature is
conditions and ~12 °C under winter conditions. The
higher than the inside then tiltable windows close. During
desirable operative temperature during “Full operation” is
higher cooling loads, the chilled ceiling and the floor
~19-20 °C under both summer and winter conditions.
cooling regulate internal temperatures. Underground air ducts support natural ventilation when fresh air supply
The main problem of the church is the inadequate
is not adequate through the tiltable windows. Fresh
thermal comfort, especially during the summer period.
air supply through the underground air ducts enhance
Between the glass and the wooden cube, temperature
thermal comfort especially in the space between the glass
is often outside of the comfort range. The 16m high and
and the wooden cube, Sensors regulate the opening and
48m long glass facade has no windows or openings,
closing of the windows. During winter period underfloor
which does not allow for effective natural ventilation.
convectors should be the main heating system as they
Furthermore, opening the large doors of the entrance of
are quick to heat giving convenient and instant warmth.
the church results in abrupt temperature changes, thus
For higher heating demand, underfloor heating supplies
further negatively affecting thermal comfort.
the church with additional heating. 8
Underfloor heating
Convectors
WINTER
High heating load
Windows open
Higher heating demand
Natural ventilation Thermal comfort achieved
Windows open Outside temp. < Inside temp.
Chilled ceiling Higher cooling load
SUMMER Outside temp. > Inside temp.
Fresh air supply through underground horizontal air ducts Outside air temperature >26 oC
Floor cooling Windows close
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Night ventilation through tiltable windows when necessary
FACADE DETAILS
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Maria Voukia 2014
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