Since the energy label in Portugal is based on an evaluation of primary energy, equipments for ambient heating, ambient cooling and production of domestic hot water have, besides the envelope and the climate, a critical influence in the result. In order to analyse the influence of the equipments, several scenarios were considered, as listed in Table 4.
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Table 2 : Main characteristics of case-studies (as in the base-cases)
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Apartment T1
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Dwelling
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Floor area (m2)
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53.5
|
150.4
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External wall area (m2)
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30.4
|
132.7
|
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Shape factor
|
0.70
|
0.75
|
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Main wall U-value (W/m2.°C)
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0.57
|
0.68
|
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Planar thermal bridge U-value (W/m2.°C)
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1.12
|
0.86
|
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Roof area
|
—
|
80.1
|
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Main roof U-value (W/m2.°C)
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—
|
0.42
|
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Window area (m2)
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12.2
|
28.6
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Main window U-value (W/m2.°C)
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3.1
|
2.9
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Main window orientation
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NE
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NW and SW
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Main window shading device
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External roller blinds, except 1 glazed door with internal curtains.
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External roller blinds
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Nominal air change rate (infiltration)
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0.94 ach’1
|
1.1 ach-1
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Thermal inertia
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high
|
high
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Other characteristics
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— Garage under the floor.
— Shading from nearby buildings
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— 2 floors, incl/ garage
— No relevant obstructions
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Table 3: Main characteristics of the selected climates
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Climatic Zone
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|
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solar radiation [kWh/m2]
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Location
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|
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Heating
|
Heating
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Winter, on
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Summer, on
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Winter
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Summer
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degree-days
|
months
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South surface
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Horizontal surface
|
|
|
|
|
|
per month
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June to September
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Braganja
|
I3
|
V2 N
|
2850
|
8
|
90
|
790
|
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Evora
|
I1
|
V3 S
|
1390
|
5.7
|
108
|
820
|
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Faro
|
I1
|
V2 S
|
1060
|
4.3
|
108
|
820
|
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Guarda
|
I3
|
V1 N
|
2956
|
8
|
90
|
730
|
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Lisboa
|
I1
|
V2 S
|
1190
|
5.3
|
108
|
820
|
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Penhas Douradas
|
I3
|
V1 N
|
3400
|
8
|
90
|
730
|
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Viana do Castelo
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I2
|
V1 N
|
1760
|
6.3
|
92
|
730
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|
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Table 4: Heating, cooling and DWH equipment scenarios considered
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Scenario
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Ambient heating
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Ambient cooling
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Domestic hot water
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|
Eqpt. 1
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Gas boiler
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Heat pump
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Gas boiler
|
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Eqpt. 2
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Gas boiler
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Heat Pump
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Solar collector + gas boiler
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|
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1st International Congress on Heating, Cooling, and Buildings, 7th to 10th October, Lisbon — Portugal /
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Eqpt. 3
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Heat pump
|
Heat pump
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Electrical resistance
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Eqpt. 4
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Heat pump
|
Heat pump
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Gas boiler
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Eqpt. 5
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Heat pump
|
Heat pump
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Solar collector + electrical resistance
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|
Eqpt. 6
|
Heat pump
|
Heat pump
|
Solar collector + gas boiler
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|
