: C1 |; o$ o# J! Woption 1: Two seperated furnances and seperated control 9 y6 s- j% ?) x8 n" _( y+ ~ (for big house > 3000 ft) - c; b" E4 o7 coption 2: One furnance with Zone Control device ; r* T% Z4 H1 z m U0 k5 o (three zones or fours zone will be good) - total efficiency will be higher& d. @3 W- r/ o# U3 @. g* u
P5 i0 @9 q ^0 v# B0 uTotal cost is not big difference.