ZEMCH 2019 International Conference Proceedings April.2020 | Page 295
Figure 1. Left: original house design; Right: house design adapted (own elaboration)
The building materiality of the outer envelope is modified to improve their thermal conditions.
An additional insulation is established on each envelope surfaces. External cladding with expanded
polystyrene is applied in the walls; window frames with double glass and air‐chamber, high density
polystyrene insulation under the floor and glass wool in the ceiling of the upper floor. With the
insulation proposed and resulting U values the house is simulated with TRNSYS® software and its
TRNBUILD® (Type 56) to get the energy demands for internal comfort. Then, PV and thermal efficiency
according to irradiation levels is calculated with F‐Chart tool, to get a possible energy production for
60 years of life expectancy according the Powerhouse standard [13]. After that a conversion on
Gigajoules is calculated, to express the energy embodied expectancy to reach the carbon neutrality
requirement.
3.
Results
The energy simulation of the house studied done with software TRNSYS 17.0 regarded local
climatic data from Meteonorm@, and TRNBUILD module was used to calculate demands and solar
capture in different inclinations and orientations of the roof. This tool considers local weather, thermal,
solar irradiation (direct, diffuse and albedo) and winds in the model analysed. Based on this, the
simulations show the indoor performance, with the energy demands for schedules occupation of each
space (living room, kitchen and bedrooms). As expected, the results show an increase in heating
consumption when the back façade increases its deviation from the solar exposition toward real north
orientation. When the main façade for solar collection is facing to north, the average annual demand is
34.45 kWh per m2. The higher demand for heating is observed with the maximum deviation analysed
(94º), getting a requirement of 41.91 kWh/m2; in intermediate conditions ‐ with deviations between 19º
and 55º ‐ an average annual demand of 35.83 kWh/m2 and 35.90 kWh/m2, respectively, is observed.
Consequently, there is a considerable reduction in irradiation capture when the deviation from the best
deposition for solar capture is consistent. If the collector façade has a deviation greater than 45º in
relation to the optimum, the thermal demand increases by 21.7%; however, with intermediate
deviations from north the increase is reduced (4.0% and 4.2%). Then, with passive strategies, a
reduction of thermal demands is achieved from 74%, in an average day of June (winter season), to 70%,
in an average day of an inter‐seasonal month according to typical demands.
3.1. BIPV technology potential
The geometry of the roof surfaces allows to install 54 BIPV panels according size of commercial
products available in the region; corresponding to a net solar capture area of 70.2 m2. In this option,
the ratio of collection surface to the building surface is 0.71. As well for the passive solar capture, the
simulation shows that the sunlight reaches an important slope during June specially. On the contrary,
between December and January the direct solar incidence is high, then it is required to avoid
overheating in summer. According to simulation, electrical production of panels is matched to energy
Evaluation of Energy Self-supply in Single Family Homes of Concepción, Chile
284