It has been a long time since we've updated you with progress on our datacenter expansion, mostly because the project has been delayed by weather. The last part of our current expansion involves work on our roof, and we've had roughly six straight weeks of rainy weather here in the Pacific Northwest. Not shocking to anyone, but usually September and early October are rather mild and dry around here. That is until we want to open up holes in our roof!

So here is what the roof looks like as of today:

Sharp eyed observers will note the lack of rainfall and unusually clear skies. The forecast calls for stable, mostly clear weather for the next several days. That means we're rolling again! Our primary contractor McDonald-Miller should be starting their roof penetrations very soon. We have to create openings in the roof for cold air supply, and hot air return for the datacenter. The supply goes into the existing cold air plenum, and the returns will be new openings in datacenter two. These should happen between now and Friday, along with roofing work to surround them.

After that we'll be erecting a steel superstructure across the section of rooftop you see above. This will be attached to the main vertical supports of the building. On top of that will be room for several HVAC units. We'll start with just two, which will more than double our current cooling capacity. The beauty of this design is that it will allow us to expand our cooling capacity easily, with minimal impact on the building itself. It also means we can add much more cooling capacity than was envisioned by the building's designers. They originally planned for HVAC units that sit directly on the roof itself. Here are photographs of our existing units:

Above: This is our main HVAC system. It is a 75 ton Trane Intellipak with a humidity control unit. It is hard to see from this angle due to the duct work hiding the main unit, but it is HUGE and covers virtually all of the south end of the building's roof.

Above: This is our Secondary HVAC system. It is also a Trane IntelliPak, but has a capacity of 48 tons. It is much smaller than our primary since it lacks a humidity control unit and has less capacity and no external duct work.

You can see how these units sit directly on the roof, requiring large curbs and tie-down systems. Our new units will be attached to the steel superstructure which will actually be above the roof itself by a meter or so. This takes the load bearing job off the roof and transmits it directly to the building's frame. The original design planned for four HVAC units, with this new design we'll be able to accommodate double that.

Stay tuned for updates as work progresses.