The standard EN 15232, today in its second edition, gives a list of BACS and TBM functions that can affect the energy performance of buildings (omitting however other important functions able to improve domestic or electrical safety [15]), and introduces four different efficiency classes for buildings according to BACS and TBM systems installation:
• Class A: High energy performance BACS and TBM systems;
• Class B: Advanced BACS and TBM systems;
• Class C: Standard BACS;
• Class D: Non-energy efficient BACS.