ZEMCH 2015 - International Conference Proceedings | Page 81

Table 1 : General data of building

Unit

Value

Gross heated volume

m3

3962

Outer surface encircling the heated space

m2

1923

S/V

m-1

0.485

Usable surface

m2

948

Number of heated floors

--

3

Net internal height

m

2.7

Number of units

--

12

Table 2 : Constructive data of building
Thermal transmittance
[W/m2K]

Construction element

Description

Opaque vertical envelope

22 different stratification, as described in table 3

Transparent vertical elements

Windows with solar transmittance of 0.67 without
shielding, except for those shielded by projection of
the building

Upper horizontal enclosure

Attic in brick and cement

0.297

Lower horizontal enclosure

Attic in brick and cement

0.21

Roof covering

Pitched roof with roof tiles

0.623

Internal partitions

11 cm Brick dividers

Vertical divisions between heated
areas

Multi-Layer brick wall with inserted thermal
insulation

0.393

Horizontal divisions in heated areas

Attic in brick and cement

0.576

1.4

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Building envelope technologies as design variables
Twenty two different alternatives are considered for opaque envelope of the exterior wall. They
are picked based on their spread in the Italian building sector. This selection includes single-layer,
multilayer, with or without insulation panels as seen in Table 3, with thermal transmittances ranging from 0.134 W/m2K to 0.267 W/m2K calculated according to EN ISO 6946:2008.
Moreover, their periodic thermal transmittances (Yie) are calculated according to EN ISO 13786
and are all within the required range of national standard described in DPR 59/2009. Only the alternative No. 22 is a monolayer wall in brick with the transmittance as the limit value requested in
the standards for climatic zone E. Heating system for spaces and domestic water is assumed as the
gas boiler and no mechanical cooling and ventilation are considered according to the common
practice in traditional construction systems in Italy.
Energy simulations were conducted for all 22 alternatives and primary energy needs of the RB
for space heating and domestic hot water are obtained by means of the professional simulation
software, “Termo” which is compatible with national standard for determination of energy performance (UNI TS 11300) and models the entire building in semi-stationary state with climatic data of
city of Bologna to obtain the total primary energy needs.

Uncertainty effects of input data on cost optimal NZEB performance analysis

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