NCAR Uses MeeFog System to Prevent Electrostatic Damage to its New SupercomputerData Centers
“Wyoming is very dry, so you need to avoid any static discharge situations,” says Autry. “The MeeFog system is there to avoid reaching too-low humidity in the data center.”
Krista Laursen, NWSC Project Director
When the National Center Atmospheric Research built its new supercomputing data center, it wanted to take advantage of the free cooling available from the high, dry Wyoming environment. This made humidification a necessity in the building, because introducing the dry air would put the $35 million supercomputer at risk for electrostatic damage.
For reliable, energy-efficient humidification, NCAR installed a MeeFog system delivering fog into the air handlers, allowing them to safely use outside air.
Mark Labac, president of Edge Mechanical Systems, was the Mee representative responsible for the NCAR humidification system. The MeeFog system consisted of two FM-200-B271P ceramic plunger pumps producing 2 gpm at 1000 psi. The pumps send the water through stainless steel tubing to arrays of impaction pin nozzles in two of the Air Handling Units and in the air supply for one of the data rooms. “The MeeFog system has some very thorough water treatment systems upstream so that the water is very clean by the time we are discharging it,” says Terry Autry, PE, a mechanical engineer and senior vice president for RMH Group, the engineering and design firm that oversaw the construction and commissioning of the NWSC’s mechanical and electrical systems. “The network of distribution nozzles discharge that fog into the return air path up high, then as that air continues down into the fan walls on the lower level, that fog is absorbed into the air stream.” The MeeFog system is tied into the Johnson Metasys control system that runs the AHUs, ensuring that the both the temperature and humidity stay in the appropriate ranges no matter what the outside temperature and humidity. “Every AHU is set up for full outside air economization,” says Autry. “The offices, the UPS and battery rooms, the computing spaces, everything has that capability.”
MeeFog systems have far lower energy costs than other types of humidification systems. For example, assuming a $.065 cost per kWh for electricity, 3500 hours of operation per year and 1000 lbs. of moisture output per hour, a MeeFog system costs $700 per year, compared with $14,350 for compressed air atomizers and $128,800 for electric steam humidifiers. In addition the MeeFog systems cool the air as they humidify it. “We do get some beneficial cooling from the MeeFog humidification so the other cooling systems have to work that much less,” says Autry. But, he doesn’t include the energy savings from the cooling in any efficiency calculations. Instead, he says the real value just comes from preventing damage to the equipment. With tens of millions of dollars of equipment at stake, that value overshadows any other. “Wyoming is very dry, so you need to avoid any static discharge situations,” says Autry. “The MeeFog system is there to avoid reaching too-low humidity in the data center.”
Benefits Of Meefog Technology:
Allows data centers to safely use outside air for cooling without damaging equipment.
Lower operating costs compared to other types of humidification systems.
Cools as well as humidifies the air
The MeeFog system uses only 1hp for every 600 lbs/hr of water. That’s far less energy than used by other humidifiers.MeeFog systems can provide very precise humidification control, +/- 1% or better.
“The network of distribution nozzles discharge fog into the return air path up high, then as that air continues down into the fan walls on the lower level, that fog is absorbed into the air stream.”