Structural Design of the mCCHP-RES System - Design for Micro-Combined Cooling, Heating and Power Systems - page 195

electricity consumption of the residence. The monthly average consumption of
electric energy can be considered constant for a residence that does not use air
conditioning inside the residential space during the summer period. The standard
monthly consumption of a Romanian residence is (100

- 300) kWh and can be

considered constant for a residence.

5.4 Synthetical Estimation Based on the Residence Energy
Certi cate

5.4.1 Energy Certi cate of Building

Chapter 5 of EN 15217 states that is

represented by an overall indicator energy performance (EP) determined according
to EN 15603. The overall indicator is related to the total

“ the energy performance of a building ”

oor area A TFA in order to
facilitate the comparison of the energy performance between buildings. The type of
dimensions used to calculate A TFA is not standardized yet because there are many
different conventions in the member states. Therefore, internal dimensions, external
dimensions, and overall internal dimensions may still be used. According to EN
15217 the type of dimensions shall be speci

cation procedure. The
type of dimensions has a high impact on the indicator EP. The indicator obtained
using internal dimensions could be 20 % higher than the one obtained using the
external dimension of the same house. The type of dimensions used in the calcu-
lation has an impact not only on the indicator EP, but also on the values calculated
for the heat transfer, the hot water demand, lighting, etc. This should be remem-
bered when choosing the type of dimensions and also when setting up the calcu-
lation methods to be used when including these building services.
Different indicators can be used on a certi

ed in the certi

cate shall contain an
easy-to-understand global indicator of the energy consumption of the certi

cate. The certi

ed
building. Different forms of energy can be delivered to a building: e.g., gas, elec-
tricity, wood. The indicator will be a weighted sum of these delivered energies.
Depending on the weight chosen, the indicator can represent either primary energy,
CO 2 emissions, and total energy cost, or a weighted sum of the net delivered energy
weighted by any other parameter de ned by national energy policy.

In selection of the relevant indicators, the following points should be taken into
account:

￿ For new buildings, a measured energy indicator is not available, so a calculated

rating based on design data is the only practical means of assigning an indicator.

￿ A measured energy indicator will no longer be valid after a change of building

occupant or a change in the pattern of use of the building.

In existing public buildings where there is no change in ownership, the mea-
sured energy indicator can be a measure of the quality of the facility manage-
ment and can be used to motivate building operators and users.

￿