I am starting a new room.
8.5'w x 6'd x 8.75'h 450cf
the room division is some what determined by door placement.
6'x6.5' flowering room 400-600 watt hps?
6'x2.5'x6' veg room, 400 watt mh, clone top 2.75' cloning florescent
The exhaust will be in the ceiling of the vegetative room.
The floor is concert so fresh air will come through a wall or a door.
The climate here can we very warm and humid 90-110°F and 20-30°F on the other end.
So my thought is to either run through a door to my garage, however, I don't think that will be much different that direct outside venting with fresh air replacement, or;
vent through a wall in my house which would be hid by a dryer. However, I am very concerned with cost of additional heating cooling. It sounds like opening a window with a fan
in it.i Is this cost prohibitive or will I just need to cool or heat the room any way?

2 other exhaust issues:
I plan to use wire closet shelving for my cloning shelve and hang my MH light on a that. Is this strong enough or is heat an issue with this?
i only need about 90 cfm fan to clear the room in 5 minutes, which is a medium bath fan. is that going to move the air adequacy or is there a better way to handle it? Also will venting to my attic cause moisture issues?

Any other suggestion in design appreciated.

snew