1#feinet2001) c% l x A8 Z( Z1 l; r! t# Y
( o/ f/ L$ v+ `" b
option 1: Two seperated furnances and seperated control+ y) [1 k& ~/ C, ?3 E% `
(for big house > 3000 ft) $ c4 ~. H5 }0 y1 D) v' Doption 2: One furnance with Zone Control device ' r, ^+ s- _. `/ v
(three zones or fours zone will be good) - total efficiency will be higher8 {9 V# f; [0 ?4 B0 M4 a6 i% r
: E; `5 t3 e! ?% WTotal cost is not big difference.