ZEMCH 2015 - International Conference Proceedings | Page 470

The DB4 simulation results showed that this model has the potential to reduce its energy consumption almost to cero with the help of renewable source of energy. With this step one complete loop of the energy efficiency stage is completed and two models already fulfil the passive
house standards. Moreover, the model can still be improved by taking it again through some
steps of the loop process if more options are needed or wanted.

DB5 simulation
This simulation will work as an example of how the design can be improved by the same looping
system. Therefore, the model will pass through the step of improving its fabric envelope again
trying to improve its thermal performance. Materials with lower U-values than 0.15 will be contemplated for the procedure of this simulation. (Table 12).
Table 12: DB5 building parameters.
Building
parameters

Site

Treated floor External wall
area TFA
U-value
(m2)
(W/m2K)

DB5

Londrina, Brazil

66.67

0.140

Windows
(including
frames)
U-value
(W/m2K)

Roof surface
U-value
(W/m2K)

Floor slab
U-value
(W/m2K)

Average
thermal
envelope

1.15

0.130

0.150

0.264

The DB5 simulation results and the achievement of the Passive house requirements are clarified
in the following table (Table 13).
Table 13: DB5 energy consumption parameters and Passive house requirements.
DB5

Heating*

Cooling*

Energy

Annual heating
demand
(kWh/m2a)

Heating load
(W/m2)

Overall space
cooling demand
(kWh/m2a)

Cooling load
(W/m2)

Consumption
parameters

0

9

17

7

Fulfil Passive
house
requirements

X

X

X

Primary Energy Energy reduction
(kWh/m2a)
through
renewables
(kWh/m2a)
113

83

X

X

*It is enough when only one of the parameters is fulfilled.

The DB5 simulation results showed that even the thermal materials have been improved and the
heating load reduced, the primary energy consumption kept almost still. Therefore, this model
does not represent a real environmental improvement. However, if the designer wants to keep
improving the project energy efficiency towards a zero energy house the next steps should be
followed. For purpose of this study only the 5 aforementioned models will be compared as eligible options during the next methodology stage.

Selecting the accurate choice
During this stage all the design options (DBx) are evaluated in order to obtain the economic,
energetic and CO2 emissions values that can be compared against each other to assess the user
and designer to select the most appropriate design option choice. Due to the characteristic of this

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ZEMCH 2015 | International Conference | Bari - Lecce, Italy