0 ^7 R$ }8 a0 u! j: Uoption 1: Two seperated furnances and seperated control9 ~2 o# f- E7 k5 g8 V, K
(for big house > 3000 ft) ' `1 Q& {+ r# G# Y* Uoption 2: One furnance with Zone Control device / M# {" J% {: o5 `7 s (three zones or fours zone will be good) - total efficiency will be higher# ^( O5 y1 f4 a" W7 k
; v. n) E ?& E5 [
Total cost is not big difference.