ZEMCH 2015 - International Conference Proceedings | Page 590

Each material is then, from time to time, assessed through the linear thermal transmittance U
achievable in the related final system, consisting of the initial stratigraphy with the addition of
the insulating panel.
This analysis must be conducted according to the current regulations on the thermal requirements of the building envelope, such as the UNI EN ISO 6946:2008 “Building components and
building elements - Thermal resistance and thermal transmittance - Calculation method”.

Cases of study
In the case of residential buildings, it must act in order to respect of the common rules, such as the
planning instruments or the regulations inside the apartment building of belonging. This case it is
problematic in the case of an intervention that acts on the exterior, which could deface or modify
the original shape of the envelope. In these conditions, the most suitable solution, especially in
the case of an energy retrofit of individual building units and not of the whole apartment building, provides for the intervention from the inside, by acting through the affixing of insulating
panels placed on the inner face of the wall.
The dwelling being examined has a floor area of 170 square meters and is used as private residence. (Figure 6).
The building was built according to a common technique in the construction of the 60’s-70’s in Palermo, through a frame system in reinforced concrete, and vertical closures in pumice concrete blocks.

Figure 6: Plan of the dwelling chosen as object of analysis.
The initial stratigraphy, having a total thickness of 25 cm, is as follows (Table 1):
- Outer surface layer: plaster type «Li Vigni», 3 cm;
- Concrete blocks of pumice stone, 25 cm thick;
- Inner layer of civil plaster and gypsum, total thickness of 2 cm.
Each layer, taken with the relative values of thermal conductivity λ and of the thickness (cm),
allows to understand the total resistance Rtot, which is in turn equal to the inverse of the transmittance U.

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ZEMCH 2015 | International Conference | Bari - Lecce, Italy