Now as to the PUE claim of 1.05, like many other broad-stroke, headline-making PUE efficiency claims, this one seems no different at first. The aggressive PUE number seemed to only cover the 'efficiency' of the EcoPOD itself, and only when the unit is using 100 percent fresh air and the DX cooling units are not running. It did seem to include any energy losses related to external infrastructure systems such as the UPS and transformer. So while the EcoPOD is a very efficient and innovative design, it seemed somewhat disappointing that HP appeared at first to have succumbed to proclaiming an ultra-low PUE, which is essentially meaningless if it is based on calculations for the EcoPOD alone. In its defense, it should be noted that HP is not alone in this practice, because many other containerized data center manufacturers have also done this, so perhaps it felt that it was a necessary evil.
Nonetheless, this seemed very unlike HP. In a follow-up telephone conversation with Wade Vinson, distinguished technologist at Hewlett Packard and chief architect for HP POD family of modular scalable data centers, aka "The Podfather," he explained that the PUE of 1.05 was correctly calculated and included a UPS operating in the so-called 'eco' mode at 98.5 percent efficiency. He went on to state that 'PUE Measured from 480V side of utility MV transformer, all the way to the server C13 & C19 plugs, so it really is the whole data center not just the POD.'
It should also be noted that the EcoPOD uses 415/240V power distribution to minimize the UPS and distribution losses and also to maximize the operating efficiency of the IT equipment power supplies (by running at 240V instead of 208V or 120V). This distribution voltage in the data center has been slow to catch on in U.S. data centers where it is primarily 480V stepped down to 208/120V, but of course in Europe 415/240V is the normal operating voltage.
HP has a multi-pronged data center offering. It began its foray beyond just offering computing hardware with the original HP POD, a containerized data center, available in 20- or 40-foot ISO-style containers. Then last year HP offered its prefabricated Flexible Data Center based on a 'butterfly' design. And all this is part of its Hybrid Delivery Strategy that allows HP to enable its Instant-On Enterprise.
The EcoPOD is not just a containerized data center on steroids. It is the next evolutionary step from the original HP POD, which is a closed environmental unit with closed-coupled cooling based on externally supplied chilled water. The EcoPOD design is also based on closed-coupled cooling, but uses direct outside air as the primary source for cool intake air and heat removal, and only uses mechanical cooling (DX units mounted overhead on a second level) if the ambient air is beyond the desired equipment intake temperature and humidity range.