1#feinet2001 & ?4 [0 W6 F O1 G0 l \) M3 k; Y0 A' x( @3 R, {% l# g
option 1: Two seperated furnances and seperated control- {% v8 K1 F0 p
(for big house > 3000 ft) O0 M7 g2 K' F( s8 \4 Joption 2: One furnance with Zone Control device 3 @, m9 C. U* E* v! Y (three zones or fours zone will be good) - total efficiency will be higher# F/ f3 L" m0 L0 e' L
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Total cost is not big difference.