The Antec P180 side air duct is a nice idea and looks good in theory, but in practice it is pretty much useless. I tried it with a couple of different fans, with the assembly half taken apart so that the fan wouldn't make sucking noises (it is just too tight of a space inside the duct for the fan to operate properly), and with the fan positioned as intake and exhaust. All to no avail. No matter what I did, the duct blew air out of the case instead of pushing fresh air onto the video card, and it was noisey no matter what kind of fan you put into it because of the tight fit. The only good thing about this duct is that it does a good job of hiding any cables that may be coming up from the lower chamber lol, and that is a GOOD thing indeed!

Antec has since stopped shipping the P180 with this side air duct, which confirms that the thing is useless, reduces manufacturing costs and in the end reduce the price of the P180 to us, the user. If I am not mistaken, it is still available as an option, but I do not reccommend ordering one. 

I eventually came up with a replacement mod using a Zalman FB123 fan bracket and 2 x 120mm Antec Tri-cool three speed 79CFM fans. The bracket attaches to the PCI retention slots in the rear of the case and is very adjustable. Putting a 120mm fan right smack dab in the same spot as the side air duct, blowing right on top of your video card. Another 120mm fan can be placed in the top position of the bracket which will blast air on top of your CPU and RAM depending on your motherboard. With my DFI Ultra D, this worked out perfectly, keeping my BH-5 ram nice and cool.

However, I eventually added an Arctic Cooler Freezer Pro 64 heatsink fan to the system, and the hight of that cooler made using the FB123 impossible... at least from the left side of the case. The slots on the sides of the 5.25 drive bays on the right side of the case allowed mounting the FB123 upside down and on the oposite side of the case, putting the lower 120mm fan in just about the exact same spot, and the upper 120mm fan still on top of my ram. This is what you see in the first picture with all the fans numbered, the one with the fans mounted on angles.

Eventually, the AC Freezer went into another system and I put a Thermalright XP-120 on the cpu, and used a Sunbeam Wherever Rack to mount the fans. This facilitated the same number of six 120mm fans in the upper chamber, but a much better layout, cleaner look, and even more adjustability. The only problem is the main bracket is too long and I have to cut it so it doesn't partially block my main 120mm exhaust.

I've aquired some metal stock and plan to build my own Wherever Rack instead of cutting this original, those pics will be posted eventually when I get time to do the work.

These most recent pics that I've added were taken after I swapped the power supply with an OCZ GameXStream 600w, and rerouted the main lines from the lower chamber to the front area where the HDDs are stored, then up to the upper chamber. This cleaned up a huge mess of wires and made the final look to be nearly perfect.

With a P180, unless you have very little component-wise, you will never have perfect cable management, but you can have very clean with some patience and modification. When I get time, I'll add more pics of how to achieve this.