Wow. Nice set up.
That's alot of work. I built the stand for my 180... but I didn't incorporate a hood or side unit. That is really creative.
Let me see if I have things correct.
Looking at your system from the front. See link:
http://www.reeffrontiers.com/forums/attachment.php?attachmentid=23440&d=1186943740
Hood.
The left wall is solid... no vents... and is clear on teh other side.
The top is solid with no vent holes... but unobstructed on the top.
The right wall is solid, and obstructed by storage and electrical.
Tha back is open... looks like about 2" from the wall.
It looks like the left side has a gap between the tank and the left wall... is this open? can air travel up the glass on the left into the hood?
Stand:
Left wall is solid. Unobstructed.
Top is open to the glass of the tank
Right wall is open to the chiller. See link.
http://www.reeffrontiers.com/forums/attachment.php?attachmentid=23434&d=1186943291
The back looks enclosed... is it?
Now, my guess is that an air temp check would reveal this:
Hood: Hot and humid.
Below tank, hot and humid... VERY.
Storage, dry and warm.
Room temp: cooler, dryer.
We know this: We do NOT want to add moisture to the air in the storage.
We do NOT want to emmit tank lighting into the room through holes in the hood.
We DO want to introduce cool air into the hood, and below tank
We DO want to vent hot air out of the hood.
If this was me and i was very intimate with this system (which i don't feel I am). I would consider the following.
1: Place 2-3 4" fans mounted into the stand wall drawing air from behind the tank. These would be placed evenly across the back wall where ever convenient. Maybe 2 near the pump (1 high, 1 low) and 1 over the sump? (I'd draw from the area of the chiller... but the chiller produces hot air (I think) and we don't want to pull hot air in.)
This will pull cool air from behind the tank and force the air to vent through the open wall over the chiller and out into the living space.
Why: This eliminates hot air under the fish tank, and cools the water in the sump... also cools the air your pump is in.
2: Small fans (2) pushing air up on the left side of the tank into the hood. These will be mounted as if they are lying flat. "--" instead of "|".
3: Install 1 or 2 fans pushing air into the canopy from directly behind the tank. You can mount these to your house's wall on an L bracket to keep them off the wall.
This will draw cool air in from 2 different points and create a little cool air turbulance and random air flow... this avoids dead spots the same way we do with water in our tanks.
4: All of these fans should be plugged into an electrical outlet that is wired to a thermostate. The thermostate can be mounted in the hood if your home is airconditioned, or set on a timer.
I like thermostats because if my lights fail to light, the AC poops out, or what ever... I don't cool when I don't need to, and I don't quit cooling when the air is still too warm. Timers don't know that.
Last...
If possible, or necessary... create a couple vent points in the top of the hood. However, to avoid light escaping, i'd build out of plastic (not clear) or metal a scoop. basically a lid over the hole/vent that allows a ton of air to pass around... but not light to pass straight through. Think of the vents on the roof of your house that stop the rain from falling in, but let the air out of your dryer, stove fan, etc.
I'd only drill the wood if I HAD to and ONLY if I KNEW FOR A FACT that it was of great benefit. Otherwise I'd experiment more.
I'm going to build a topless hood for my tank this winter to block the light bleed that hits my TV. I will use alot of the baffles i mentioned above to alow freeflow of air... but not light.
Hope that helps.
My 1 disclaimer is this. i spent an hour looking over your system... you've got way more than that. you are far more intimate with the ins and outs of it. I am always here to help someone, let me know where I have something incorrect about your set up, and I'll rethink it.
thanks for the opportunity to give input. That is a really impressive set up.
And a ton of work. my hat is off to you.