Ventilation Question

[Letterhead954]

I've recently expanded both my grow rooms, added a second light for flower and a MH for veg rather than my former T-5. . I put in a filter for the flower room and am venting outside through 6" ducting. Adding 1600 watts of lighting has significantly increased my temps. My veg room is currently venting directly into my basement, which is increasing the temp, so I have to vent that outside too. Thus my question. 

First of all, if possible I want to use my existing set-up. Since I just set this up I really don't want to have to change everything. What I'm wondering is how to best go about this. I had planned on buying a 6" ducting wye to connect the veg room duct to the flower room duct. The veg room duct would join the main duct right after the in-line fan. I have a 450 cfm inline fan for flower and a 6" duct fan (like you get at Home Depot) for veg. I know ideally I should use an 8" duct after the fans, but if I don't have to I'd rather not change it. So how do I best go about this? Do I just use a wye and keep my set-up like it is, or will back pressure be a problem? Should I use the in-line fan for both rooms and use the duct fan as a booster? If so, should I put the booster fan before or after the in-line fan? SInce the duct fan doesn't move as many air as the in-line, can I even use it as a booster? Any suggestions would be appreciated. 

[Mr. Wilson]

Depends on sizes of rooms, length of duct work, size of all components, temp and humidity of rooms, type of heating and cooling, floor level and possibly other factors.

 

More info needed or it's just wild guesswork, which sometimes it is anyway, but,...

[Letterhead954]

Got it figured out. The booster fan wasn't strong enough, so air was blowing backwards into my veg light from the wye. I bought another inline fan for my veg room and 8" ducting to run outside. I haven't put it together yet as I'm waiting on a vent from Home Depot. So yeah, I had to change everything. 

[pic book]

sounds about right.  if temps are good, every leaf is waving in the breeze and in the basement you smell fabreeze only, then you got the job done.