The first stage of the calculations was to compute the main evaluation indexes (Nic, Nvc, Nac and Ntc) for the buildings with their base-case envelope, as described in section 2. Table 5 and Table 6 show the results of the heating and cooling needs for each of the 7 analysed locations. The results show that, with the base-case envelope, the heating needs are above the allowed limit if the buildings are located in the coldest regions — Bragan? a, Guarda, Penhas Douradas and Viana do Castelo (this later one only in the case of the dwelling). The cooling needs pose no problem in any of the studied locations.
|
Table 5: Results for the apartment with the base-case envelope — heating and cooling needs
|
Lisboa
|
Bragan^a
|
Faro
|
Evora
|
Guarda
|
Penhas
Douradas
|
Viana do Castelo
|
|
Nic
(kWh/m2.year)
|
55.5
|
161.8
|
51.6
|
67.4
|
169.3
|
200.8
|
73.6
|
|
Ni Max
(kWh/m2.year)
|
60.4
|
138.4
|
54.3
|
69.8
|
143.46
|
164.3
|
75.0
|
|
Nvc
(kWh/m2.year)
|
14.7
|
2.3
|
14.7
|
14.3
|
2.0
|
2.0
|
2.0
|
|
Nv Max
(kWh/m2.year)
|
32
|
18
|
32
|
32
|
18
|
18
|
18
|
|
Compliance
|
YES
|
NO
|
YES
|
YES
|
NO
|
NO
|
YES
|
|
|
Table 6: Results for the dwelling with the base-case envelope — heating and cooling needs
|
Lisboa
|
Bragan^a
|
Faro
|
Evora
|
Guarda
|
Penhas
Douradas
|
Viana do Castelo
|
|
Nic
|
54.6
|
165.9
|
51.3
|
66.8
|
173.8
|
207.2
|
93.7
|
|
Ni max
|
62.5
|
143.3
|
56.1
|
72.2
|
148.5
|
170.1
|
90.2
|
|
Nvc
|
14.1
|
1.9
|
14.1
|
14.0
|
1.6
|
1.6
|
1.6
|
|
Nv max
|
32
|
18
|
32
|
32
|
16
|
16
|
16
|
|
Compliance
|
YES
|
NO
|
YES
|
YES
|
NO
|
NO
|
NO
|
|
The second stage of the study consisted in identifying a minimum set of envelope changes that ensures compliance with the regulation in terms of heating and cooling loads. For each location there several sets of changes that can accomplish this goal, e. g. increasing the insulation, changing from natural to mechanical ventilation with lower air change rates or optimizing the window orientation and areas. Priority was given to measures that have no or little collateral impact with other architectural features. Table 7 summarises the main changes made to the base-case in order to fulfil the regulation demands in terms of heating and cooling needs. Table 8 and Table 9 show the results of heating and cooling needs plus the final energy for water heating and the total primary energy consumption (as a ratio between the actual result and the maximum allowed) as well as the resulting energy class. The results confirm that with the envelope changes identified it is now
possible to fulfil the heating and cooling requirements (first two lines). The results also show that the final result of (Ntc/Nt) and the corresponding energy class depends very strongly in the equipments used for heating, cooling and especially for DHW production. With the equipments scenario 3, which relies solely on electric resistance for DHW it is not possible to fulfil the regulation in any of the location, while with scenarios 2 and 6, which make use of solar collectors, all buildings become class A or A+.
|
Table 7: Changes in the envelope implemented to fulfil the regulation RCCTE.
|
Location
|
Apartment
|
Dwelling
|
|
Braganja
|
— Wall insulation increased to 6 cm (U= 0.41 W/m2.°C)
— Insul. of plan. th. br. increased to 3 cm (U=0.88 W/m2.°C)
— Floor slab insulation increased to 6 cm (U=0.53)
— Night occlusion device at kitchen window, U decreasing to 3.1 W/m2.°C.
|
— Wall insulation increased to 6 cm (U=0.45 W/m2.°C at walls and 0.52 at planar thermal bridges)
— Insulation of interior envelope walls increased to 6 cm (U=0.48 W/m2.°C)
— Natural ventilation air intake grills and windows with air tightness class 2, decreasing air change to 1.0 ach-1
|
|
Guarda
|
— Wall insulation increased to 6 cm XPS (U= 0.38)
— Insulation at planar thermal bridges increased to 3 cm XPS (U=0.81 W/m2.°C)
— Floor slab insulation increased to 6 cm (U=0.46)
— Window frames with thermal break + night occlusion devices, resulting in U=2.7 W/m2.°C.
|
— Wall insulation increased to 8 cm (U=0.37 W/m2.°C at walls and 0.41 W/m2.°C at planar thermal bridges)
— Roof slab insulation increased to 8 cm (U=0.32 W/m2.°C)
|
|
Penhas
Douradas
|
— Wall insulation increased to 7cm XPS (U= 0.34 W/m2.°C)
— Insulation at planar thermal bridges increased to 6cm XPS (U=0.49 W/m2.°C)
— Floor slab insulation increased to 7cm (U=0.48)
— Window frames with thermal break + night occlusion devices, resulting in U=2.7 W/m2.°C.
|
— Wall insulation increased to 8 cm (U=0.37 W/m2.°C at walls and 0.41 at planar thermal bridges)
— Insulation of interior envelope walls increased to 6 cm (U=0.48 W/m2.°C)
— Roof slab insulation increased to 8 cm (U=0.32 W/m2.°C)
— Night occlusion device of windows + rubber strips, resulting in windows with U=2.7 W/m2.°C
|
|
Viana C.
|
—
|
— Wall insulation increased to 5 cm (U=0.51 W/m2.°C)
|
Lisbon, Faro, Evora: No changes required
|
|
Table 8: Results for the apartment after the changes in the envelope to fulfil the regulation in terms of
heating and cooling needs.
|
|
Lisboa
|
Bragan^a
|
Faro
|
Evora
|
Guarda
|
P. Dour. as
|
Viana C. l°
|
|
Nic /Ni
|
92%
|
99%
|
95%
|
97%
|
95%
|
97%
|
98%
|
|
Nvc /Nv
|
46%
|
14%
|
46%
|
45%
|
15%
|
15%
|
12%
|
|
Eqpt. 1
|
Nac / Na
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
|
Ntc /Nt
|
52% [B]
|
57% [B]
|
52% [B]
|
53% [B]
|
57% [B]
|
58% [B]
|
53% [B]
|
|
Eqpt. 2
|
Nac / Na
|
22%
|
26%
|
21%
|
21%
|
26%
|
27%
|
28%
|
|
Ntc /Nt
|
23% [A+]
|
32% [A]
|
21% [A+]
|
23% [A+]
|
32% [A]
|
35% [A]
|
26% [A]
|
|
Eqpt. 3
|
Nac / Na
|
68%
|
68%
|
68%
|
68%
|
68%
|
68%
|
68%
|
|
Ntc /Nt
|
136% [NC]
|
132% [NC]
|
137% [NC]
|
136% [NC]
|
129% [NC]
|
128% [NC]
|
137% [NC]
|
|
Eqpt. 4
|
Nac / Na
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
|
Ntc /Nt
|
50% [A]
|
52% [B]
|
50% [A]
|
50% [B]
|
52% [B]
|
53% [B]
|
50% [A]
|
|
Eqpt. 5
|
Nac / Na
|
16%
|
20%
|
14%
|
15%
|
20%
|
21%
|
21%
|
|
|
1st International Congress on Heating, Cooling, and Buildings, 7th to 10th October, Lisbon — Portugal /
|
Ntc /Nt
|
38% [A]
|
49% [A]
|
35% [A]
|
36% [A]
|
48% [A]
|
51% [B]
|
48% [A]
|
|
Eqpt. 6
|
Nac / Na
|
22%
|
26%
|
21%
|
21%
|
26%
|
27%
|
28%
|
|
Ntc /Nt
|
21% [A+]
|
27% [A]
|
19% [A+]
|
21% [A+]
|
27% [A]
|
29% [A]
|
24% [A+]
|
NC. = Not Compliant
|
|
Table 9: Results for the dwelling after the changes to meet the heating and cooling needs requirements
|
|
Lisboa
|
Bragan^a
|
Faro
|
Evora
|
Guarda
|
P. Dour. as
|
Viana C. l°
|
|
Nic /Ni
|
87%
|
100%
|
91%
|
93%
|
99%
|
99%
|
98%
|
|
Nvc /Nv
|
44%
|
16%
|
44%
|
44%
|
15%
|
14%
|
12%
|
|
Eqpt. 1
|
Nac / Na
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
|
Ntc /Nt
|
53% [B]
|
61% [B]
|
53% [B]
|
54% [B]
|
61% [B]
|
62% [B]
|
56% [B]
|
|
Eqpt. 2
|
Nac / Na
|
26%
|
30%
|
24%
|
24%
|
30%
|
30%
|
31%
|
|
Ntc /Nt
|
27% [A]
|
39% [A]
|
26% [A]
|
28% [A]
|
40% [A]
|
42% [A]
|
33% [A]
|
|
Eqpt. 3
|
Nac / Na
|
68%
|
68%
|
68%
|
68%
|
68%
|
68%
|
68%
|
|
Ntc /Nt
|
134% [NC]
|
129% [NC]
|
135% [NC]
|
133% [NC]
|
127% [NC]
|
125% [NC]
|
133% [NC]
|
|
Eqpt. 4
|
Nac / Na
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
74%
|
|
Ntc /Nt
|
50% [A]
|
54% [B]
|
50% [A]
|
51% [B]
|
54% [B]
|
55% [B]
|
51% [B]
|
|
Eqpt. 5
|
Nac / Na
|
19%
|
23%
|
18%
|
18%
|
23%
|
24%
|
25%
|
|
Ntc /Nt
|
45% [A]
|
56% [B]
|
42% [A]
|
43% [A]
|
56% [B]
|
58% [B]
|
56% [B]
|
|
Eqpt. 6
|
Nac / Na
|
26%
|
30%
|
24%
|
18%
|
30%
|
30%
|
31%
|
|
Ntc /Nt
|
24% [A+]
|
33% [A]
|
23% [A+]
|
24% [A+]
|
33% [A]
|
35% [A]
|
29% [A]
|
|
