Many of the engagements that we work involve producing the initial conceptual layout for construction of a data center. As a certified design consultant, we draw upon best practices reflected in the BICSI-002 standard, TIA-942, et. al. Even when the raw space with which we’re working is a nice big rectangle, this job can be much more complicated than it may appear.
Included in the complexity of data center design layout are factors such as physical security of the IT space with respect to the perimeter walls, personnel and material traffic flow for daily operations and equipment refresh, power cable and plumbing topology, fire/building codes, and a basket full of other topics. One of the most prevalent in this context is to design sufficient space for the Back-of-House (BOH, comprised of electrical switchboards, transformers, batteries, UPS systems, PDU’s, pumps, chillers, et. al.) equipment while still delivering the required yield of the IT or Computer Room floor.
Payload Space vs. Back of House Space
The financial model for a given data center will assume a certain yield of the IT floor. Said another way, realizing the financial benefits of the investment is dependent upon the facilities ability to support some minimum number of cabinets, racks, systems, or whatever basic component the yield metric is built upon. As a simple example, let’s say we’re given a 5,000 square foot space to work with, and we have to support 100 IT cabinets at an average of 4kW per cabinet. Will that work? How much of that 5,000 square feet is dedicated to BOH equipment? Maybe we can do it, maybe we can’t. The point is that the electrical and mechanical equipment necessary in the facility often can require as much space as we plan for the IT equipment payload for which we’re building the data center in the first place.
Let’s go 3-D
Clever data center designers are finding success thinking beyond the traditional two-dimensional layout model and taking advantage of vertical space. If the BOH equipment can be designed onto a level above or below the IT Computer Room floor, then we relieve the space restrictions on our payload area.
The following video is from Power Loft, which recently deployed a data center based on this clever thinking. This is a two-story data center in Manassas, VA that places the BOH infrastructure on the bottom floor, and the IT Computer Room equipment on the upper floor. The result is a facility that facilitates growth and expansion of the IT footprint without disruption to the raised floor area.
We are seeing increasing activity in this way of planning data center space for high capacity and high yield. Some providers, for example, are beginning to locate Computer Room Air Handlers (CRAHs) on an elevated mezzanine above the Computer Room floor so that payload space is not compromised by cooling equipment. This design brings other advantages too, as the high ceiling provides ample room for hot air to rise away from the IT racks. Even Remote Power Panels (RPPs) are suspended from above near Customer cages for efficient delivery of rack power without impacting floor space.
The caveat in whether this is an option for a given site of course depends on the physical architecture of the building. That is, the space has to be very tall in order to take advantage of this, or the building has to have the right sort of space available on adjacent stories. When assisting our Clients with site selections, we keep in mind the potential benefits of tall spaces or multi-story buildings, for delivery of necessary yield in the project.