Table 4: DB energy consumption parameters and Passive house requirements.
DB Heating * Cooling * Energy
Annual heating demand( kWh / m2a)
Heating load( W / m2)
Overall space Cooling load( W / cooling demand m2)
( kWh / m2a)
Primary Energy( kWh / m2a)
Energy reduction through renewables( kWh / m2a)
Consumption parameters
Fulfil Passive house requirements
0 54 65 65 295-
X
* It is enough when only one of the parameters is fulfilled.
In the DB simulation results, it is observed that the cooling demand got higher due to the solar direct penetration and less heat is lost because of the east and west walls transformed into partition walls. However, the cooling loads considerably decrease and therefore the primary energy consumption as well. After this process the bioclimatic features should be applied in the next steps.
DB1 simulation
The first step during the energy efficiency upgrading stage consists on improving the thermal characteristics of the fabric materials by reducing their U-values and thermal bridges. If the modifications made during this step do not achieve the passive house requirements this model should not be consider as a design option. This study will name the prototype as DB1 in order to examine the full method and be able to generate a comparison table that shows all the modifications made. The prototype will be conceived with the sustainable materials provided by the LP Company( Table 12)( Figs. 18,19).
Table 5: DB1 building parameters. |
Building parameters |
Site |
Treated floor area TFA( m2) |
External wall U-value( W / m2K)
Windows( including frames) U-value( W / m2K)
Roof surface U-value( W / m2K)
Floor slab U-value( W / m2K)
Average thermal envelope
DB1 Londrina, Brazil 66.67 0.369 2.556 0.400 1.200 0.886
Figure 18: DB1 plan, section and heat sources.
Design decision-making process of affordable low energy homes in Latin America 463