1#feinet2001 Y' S# o+ N" @3 k+ U
, C, g8 ` S. v/ ~/ G
option 1: Two seperated furnances and seperated control+ Q. Y" ]3 D! w! T
(for big house > 3000 ft)8 ~9 W' Y) Z) F" K' g& z0 n
option 2: One furnance with Zone Control device & b6 [, E; Y* l (three zones or fours zone will be good) - total efficiency will be higher8 ]* l+ m3 m5 M% t u
) T* R$ Q$ V) }: ` A9 r+ n
Total cost is not big difference.