Water cooling is often used for heat management in data centres, but that creates its own challenges. Corrosion, algae, bacteria and fungus can damage those cooling systems. Beware the prolific biofilm slime formers!
Lifehacker’s coverage of Data Center World 2014 is presented by the Microsoft Cloud, providing flexible enterprise cloud solutions for business.
During a presentation at Data Center World 2014 in Las Vegas, Fremont director of sales Rob Herbon highlighted some of the issues that can arise if water used in cooling systems isn’t fully treated to remove bacteria, algae, fungus and other lifeforms, and shared these images of damaged equipment encountered by the company.
Active corrosion on a chiller exchanger head.
While corrosion might seem like an obvious risk, Herbon said other areas could be more problematic. “We see more problems in the holding systems for chilled water loops — that tends to be the more critical issue.”
Corrosion on a chiller tube sheet.
Films that form in water can creates “mats” which in turn block the flow in cooling systems.
A mat of organic matter in a TES tank.
Avoiding these problems requires planning in advance and ongoing maintenance. “Get the water out if you’re not using a facility,” Herbon advised. “Keeping the system clean is vital.”
Corrosion can also create other byproducts (see the bottom left of the picture).
In some instances, untreated water can cause major dramas. “Bacteria can grow so fast it causes the cooling tower to fall over,” Herbon said.
There are also health risks for staff: if legionella or other bacteria develop in water systems, the results can be fatal.
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One response to “Gallery: How Corrosion, Algae And Bacteria Can Ruin A Data Centre”
I gather it’s not possible to use Distilled water? Perhaps in conjunction with some type of heat exchanger, therefore reducing the amount of components in contact with the untreated water.
What is occurring here is “Bio Fouling”, with the root cause being biofilm build up on the external and internal aspects of the HVAC / cooling system.
The external aspects of the coils are designed to strip the moisture out of the air, (in the case of Liebert units, which are most common in data centers, this occurs both on the units on the floor, as well as the roof top components), and so by default become biofilm generators. Biofilm is the greatest impediment to the thermal efficiency of any HVAC units (bar leaking ducts) and so its presence on the external aspects of the coils is costly in terms of energy usage.
When it comes to the internal aspects of the coil’s tubing, water treatment processes such as acid, chlorine dioxide and / or oxidizers such as hydrogen peroxide, have been proven to be ineffective at preventing the build up of biofilm on the internal aspects of the coil’s tubing (the photos above here are a prime example). Over time the biofilm creates bio-corrosion of the coil , especially the internal aspects of the tubing), as well as becoming a “glue” to which mineral deposits and oxidized metal generated from the bio-corrosion adhere, closing the diameter of the tubing and so becoming a “double whammy” in terms of reducing the efficacy of the unit.
There are 3 methods of removing biofilm; (a) abrasion, (b) chemical and (c) detachment. In HVAC units, especially those in data centers, abrasion is impractical to virtually impossible. Chemical water treatments are proven in effective and fail. So generating “detachment” is the “Holy Grail”.
Clean & Green HVAC, a new company in the US has after 3 yrs of infield testing and trials with “early adopter” clients demonstrated that its pH neutral, totally green HVAC cleaning agents (for use on the external and internal aspects of coils, as well as cooling towers, generates “detachment” of biofilm and so can be used to prevent the onset of bio-corrosion and in doing so reduce operating and energy costs, improve unit performance and extend equipment life cycles. Its website is under construction, but details can be obtained either by emailing: [email protected] and / or contacting one of its field contractor partners, Jeff Seippel via the http://www.greenairenviro.com website.