• The additional space and gross floor area (GFA) for adding ventilation façade might extrude from the existing structure and out of site area. Details checking has to be made prior to design process.
• Different material of the ventilation façade should have different degree of energy efficiency. E.g. tiles, glass-fiber reinforced concrete panel, and stone, etc.
• Drainage system should be integrated in order to have better design result.
• Building submission for the alterations and additions works is needed. 

QFACADE = [Af*SF*SC*a*(1-F_FIN)(1-F_HANG)(1-F_VENT)]_PRE – [Af*SF*SC*a*(1-F_FIN)(1-F_HING)(1-F_VENT)]_POST

QFACADE = [Ag*SF*SC*min(ESM_FIN, ESM_HANG)]_PRE – [Ag*SF*SC*min(ESM_FIN, ESM_HANG)]_POST+ [Ag*Ug*a*DT_EQ,V+ Asky*Usky*a*DT_EQ,H]_PRE – [Ag*Ug*a*DT_EQ,V+ Asky*Usky*a*DT_EQ,H]_POST+ [Asky*SF*SC]_PRE – [Asky*SF*SC]_POST

kW_FACADE = 1/COP*QFACADE*OPHR,yr

where   Ag = glazing area; Asky = skylight area

                Ug, Usky = U-value of glazing and skylight

SF = solar factor (orientated); SC = shading coefficient

                a = outer surface absorptivity of façade

DT_EQ,V, DT_EQ,H = equivalent temperature different of wall and roof (orientation)

ESM_FIN, ESM_HANG = external shading multiplier of fin and overhang

F_VENT = Heat penetration prevention factor for ventilated façade, it affect U-value of glazing by adding air-insulation, and increase h-value, as well as reducing solar transmission (i.e. SC may change)

Please click HERE to view the list of terminology.