## 3 Results  
In the following figures, the results of the acoustic predictions made for the day period at a height of 4 m, as is specified in EU DIRECTIVE 2002/49/EC, and also at 10 m are presented for each scenario. Predictions with noise levels at 10 m were performed in order to observe the noise propagation at upper floors. Considering in this case that the noise sources are situated at 6 m height from the ground on a reflective surface, the noise propagation must be evaluated at different heights. The noise map resulting from Scenario 1 at a height of 4 m (see Figure 5) emphasizes that the noise emission produced by the cooling systems is screened by the roof of the building, the supply ramp source is stronger than the other sources and the noise propagation is directed towards the two buildings in the north and east. In the noise map obtained at a height of 10 m, it is observed that the noise is widespread and the building facades are exposed to higher noise levels due to the fact that the levels of the two noise sources are summed. By installing a barrier with a height of only 2.3 m in parallel with the unloading area (see Figure 6) at heights under 4 m, the supply activity noise will be directed along the barrier, while at higher heights, the noise has almost the same mode of dispersion as in Scenario 1 but with lower amplitudes. A better reduction in noise propagation at a higher height can be achieved only by installing very high acoustic barriers, as shown in Scenario 3. Figure 4: 3D model with the cooling systems, supply ramp and residential buildings ((**A**) Scenario 1, (**B**) Scenario 2, (**C**) Scenario 3, (**D**) Scenario 4, (**E**) Scenario 5). Figure 5: Scenario 1 with no technical solution—Lday with all noise sources (**left**: 4 m, **right**: 10 m). As is presented in Figure 7, at low heights, these acoustic barriers with a total height of 5.5 m lead to an accentuation of the noise propagation along them. It can also be seen that the space left between the barrier and the centre of the building leads to multiple reflections between them, producing a leak of noise that spreads to the north of the building. Due to the height of the barriers and the sloping portion, the noise is \"trapped\" and the propagation at upper floors is smaller than in Scenario 2. The next technical solution is designed to maintain and absorb the supply noise without letting it propagate freely. In Scenario 4 (see Figure 8), an interesting effect is produced which can be observed in the noise map from 10 m. The noise from the supply ramp, which until now was the major one, in this case it have almost the same amplitude as the noise generated by the cooling systems from the roof. This effect is given by the uniform directivity of noise and the absence of acoustic lobes. Due to the continuous functioning regime of the chiller and its tonal character, another solution is proposed to be studied, in which a set of acoustic barriers is mounted on the roof next to the cooling systems. Figure 6: Scenario 2 with acoustic barrier of 2.3 m—Lday with all noise sources (**left**: 4 m, **right**: 10 m). Figure 7: Scenario 3 with a sloped acoustic barrier and higher height—Lday with all noise sources (**left**: 4 m, **right**: 10 m). The noise maps for Scenario 5 (see Figure 9) highlight that the acoustic barriers have an outstanding effect at both studied heights, the noise being reduced especially in the north and in west parts. In the east part, the remaining noise is caused by the transmission of the supply ramp noise through the enclosure walls which was presented in Scenario 4. Figure 10 presents the noise levels calculated in each receiver point for each scenario for the day period. The sound pressure levels were evaluated at 1.5 m, in accordance with the national legislation. Figure 8: Scenario 4 with a supply ramp inside a construction—Lday with all noise sources (**left**: 4 m, **right**: 10 m). Figure 10: Noise level in each receiver at 1.5 m—Lday with all noise sources.