1#feinet2001 ; ^0 h# r! k- |# _ 0 O; b* s6 u# O* V/ ]8 _% `option 1: Two seperated furnances and seperated control : N* I: Y" Z% t5 @# b8 R! H (for big house > 3000 ft)! P: o4 f6 v" {% k) Y
option 2: One furnance with Zone Control device " A% o$ S5 y! v% S( B- t (three zones or fours zone will be good) - total efficiency will be higher ; V; @- Y5 C& k5 {6 G' E6 Q D6 X4 W, \5 h
Total cost is not big difference.