We’re constantly hearing about how the lack of rain in much of the Southwest has contributed to the worst drought in the history of the region, but the subject of water doesn’t come up much with respect to data centers.
However, it should garner just as much attention—specifically water treatment programs—according to Data Center World speaker Robert O’Donnell, managing partner of Aquanomix.
“The water management program is a huge risk in data centers; one that many facility owners don’t understand or give enough credence to,” he says.
In O’Donnell’s session, “Cause & Effect: The Hidden Risk in Your Data Center,” he will focus on how a water treatment controller that monitors the quality of the water pumping through your chiller plant has a tendency to corrode, scale, foul, or support microbiological growth in the system.
“These effects can take your data center down, and quickly. The relationship between your system’s heat exchangers and water management is a vulnerable target that’s easily managed,” says O’Donnell.
Unlike the drought, the issue isn’t just the quantity of water used, but also the quality of that water. To operate at peak efficiency, facilities must ensure that the water they use is pure and that the piping is free of biofilm and corrosion.
Wherever water is used, biofilm and rust are concerns. Biofilms are formed by microbes that grow on the inner surfaces of pipes and other water containment vessels. Rust—iron oxide formed by the redox reaction of iron and oxygen—also forms inside pipes and deposits precipitates in the water.
Mild steel, galvanized iron with copper and zinc coatings, stainless steel, copper alloys and plastic are all used in water systems. Likewise, the water itself has varying properties that affect cooling systems, including hardness, alkalinity, total suspended solids, ammonia and chloride.
For example, chlorine, a common water purifying agent, corrodes most metals. Ammonia is used to produce chloramine, a less aggressive alternative to chlorine, but promotes biofilm development in heat exchangers and in the cooling tower. Additionally, with hard water, as water temperature increases, calcium salts precipitate out.
The costs of biofouling and scaling can be significant. For example, a 1,000-ton air conditioner operating 12 hours per day at a cost of 20 cents per kWh would cost $29,932 each year to operate with only 0.012 inches of scaling and biofilm. When that scaling and biofilm triples, so do costs.
“The variability of water quality DIRECTLY affects heat exchange, energy use, and water use. You need to recognize the criticality of continuously monitoring and analyzing the water quality and energy use,” O’Donnell says.
This first ran at http://www.afcom.com/news/cause-effect-hidden-risk-data-center/