/ p: \8 Y5 h' R, p% ~3 V: k8 N Aoption 1: Two seperated furnances and seperated control o6 Z0 Z! ?; `, S (for big house > 3000 ft) , ^# s9 l: f: ]/ u5 @3 Joption 2: One furnance with Zone Control device - d, |2 {+ W9 W9 ?. F/ e; r
(three zones or fours zone will be good) - total efficiency will be higher8 |# G; `% v. _
3 b3 l) D7 G" e) b9 [
Total cost is not big difference.