IBM 8408-44E Site And Hardware Planning page 89

– Failure of mechanical hardware, such as a hose quick-connect coupling
v Organic contamination, such as bacteria, fungi, or algae. This contamination can cause the same
problems as described for scale deposits.
Contact a water quality and water distribution services expert for designing and implementing the
infrastructure and water chemistry of the secondary loop.
Control and conditioning of the secondary cooling loop
The water that is used to fill, refill, and supply the heat exchanger must be particle-free deionized water
or particle-free distilled water with appropriate controls for avoiding the following problems:
v Metal corrosion
v Bacterial fouling
v Scaling
The water cannot originate from the primary chilled-water system for the building but must be supplied
as part of a secondary closed-loop system.
Important: Do not use glycol solutions because they can adversely affect the cooling performance of the
heat exchanger.
Materials to use in secondary loops
You can use any of the following materials in supply lines, connectors, manifolds, pumps, and any other
hardware that makes up the closed-loop water-supply system at your location:
v Copper v brass with less than 30% zinc content
v Brass with less than 30% zinc content
v Stainless steel 303 or 316
v Peroxide cured ethylene propylene diene monomer (EPDM) rubber, non-metal-oxide material
Materials to avoid in secondary loops
Do not use any of the following materials in any part of your water-supply system:
v Oxidizing biocides, such as chlorine, bromine, and chlorine dioxide
v Aluminum
v Brass with greater than 30% zinc
v Irons (nonstainless steel)
Water-supply requirements for secondary loops
Learn about the specific characteristics of the system that supplies the chilled conditioned water to the
heat exchanger.
Temperature:
The heat exchanger and its supply hose and return hoses are not insulated. Avoid any condition
that might cause condensation. The temperature of the water inside the supply hose, return hose,
and heat exchanger must be kept above the dew point of the location where the heat exchanger is
being used.
Attention: Typical primary chilled water is too cold for use in this application because building
chilled water can be as cold as 4°C - 6°C (39°F - 43°F).
Important:
Site and hardware planning
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