Lennox FLEXY II Series Installation, Operating And Maintenance page 40

VENTILATION : AIRFLOW BALANCING
AT15-15G2L(*)
(*) The performanc es of twin fan units can be calc ulated starting from the c orresponding oper ation point for a si ngle fan
(see the figure behind) by appl ying the formulas below.
- pressure : PT win = P x 1
- vol ume flow rate : Qb = Q x 2
- impeller power: Wb = W x 2,15
- fan s peed : Nb = N x 1,05
- Lws : Lwsb = Lws + 3 dB
IOM – FLEXY II – 1007 – E Page 38