4 T6 |7 y9 z8 {( X& l; zoption 1: Two seperated furnances and seperated control( E, V, T- v; s5 \0 _
(for big house > 3000 ft) ( w0 A% a) X3 ~; zoption 2: One furnance with Zone Control device 0 C9 L# ?3 [6 U7 y' \
(three zones or fours zone will be good) - total efficiency will be higher! ?4 N9 L3 ~$ c
; |7 T7 G# w2 f* YTotal cost is not big difference.