The main mining room is in a detached large garage with 6 inch ducted intake of outside ambient air using a 530CFM inline fan:
http://www.amazon.com/gp/product/B005XNNYMU/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B005XNNYMU&linkCode=as2&tag=jedislair-20&linkId=NF4UYTVCZHA7P3CU



Hot air exhausts through a box fan raised on an old dog kennel near the room's door to the main garage space.

The desktop USB miners are cooled using white LED Coolermaster JetFlo 120 fans using a desktop fan controller.

The Drillbit boards also use JetFlo 120's.

There's also a vornado fan blowing on the ASICMiner BlockErupter 49port USB hub.

The GPU ScryptMiner just uses a large box fan.

I have various temp/humidity sensors setup in the Mining a Room and in the main garage space as well as security cameras so I can monitor temp/humidity and cameras from my ipad or phone. Doors are touchpad locked with remote unlock capability.

I have a mix of 120v/20a and 230v/30a power distributed in the garage which is on a separate electric meter than my house and has a separate commercial/agricultural electricity rate/bill (much much cheaper than the household rates).

I use HP Server PSUs with Gigampz Adapters and Klondike_bar's PCI-E cables powering most of the S1's (except for two powered by a Seasonic 1200w Platinum). You can find out more about the Gigampz here: https://bitcointalk.org/index.php?topic=622783.0