User Manual

101
Calculation procedure per EN 15232
The basis for energy demand calculations in buildings are…
· the "Energy flow diagram for a building" presented earlier,
· procedures as per standards for the corresponding partial installations of building and HVAC
partial plants.
The building type corresponding to the occupancy profile is considered when calculating energy
demand. The building’s exterior shell is subjected to defined outside weather patterns.
You can determine the impact of BAC functions on the energy efficiency of a building by
comparing two energy demand calculations for a building using various building automation
functions.
The calculation of the impact of the building automation and control and building management
functions on the energy efficiency of a building can be accomplished using either a detailed method
or the BACS factor method. The following figure illustrates how to use the different approaches.
Differences between the detailed and BACS factor method in EN 15232 (the arrows only serve to
point out the calculation process and do not represent the energy flow and/or mass flow)
Key:
a Energy use for heating, cooling, ventilation, DHW or lighting
b Delivered energy is the total energy, expressed per energy carrier
(natural gas, oil, electricity, etc.). [CEN/TR 15615, Figure 2]
BACS Factor method
(Refer to EN 15232, Section 6)
Building
Energy use
Energy use
Energy use
Detailed or simplified
calculated with
reference BACS class
b
b
Detailed method
Delivered energy Delivered energy
a
a
Plants/systems
Detailed calculation
of energy use with
BACS
BACS efficiency
factor