The flow chart for designing an optimal HVAC system is shown
in Fig. 1. TRNSYS is utilized in this study in order to calculate the
energy demand for cooling and heating of an objective building
[22,23] . And then an optimal operation pattern and combination of
HVAC system to minimize primary energy consumption are suggested using the MIGA, which includes input conditions such as
equipment system data, GA parameters and demand data. In this
research, MIGA is adapted to select combination of HVAC system
which needs enormous calculation practice [23,24] . MIGA is superior to avoid converging partial optimal solution that is easy to occur
in Simple GA. MIGA is one of the optimal methods of parallel distribution. MIGA performs calculation among islands, which divide population into some island (sub-population). Exchanging of the
individual information called “migration” among each island regularly evades the outbreak of the partially optimization every several
generations once [5,6,24] .