FOCUS COOLING
Issue 5, Aug/Sep 2009
evaluation, only a comprehensive laboratory analysis can determine the actual constituents.
Understanding processes will influence the decision of whether it is a physical, chemical or statistical reason to perform a water quality test. Does the water contain materials that will inhibit the heat transfer process? Will the water in question corrode your heat transfer system? Will filtration or pre-processing be necessary before use in the cooling system?
Chemical testing to determine these answers may include data points for pH, hardness, chlorides and iron. Additional testing can address contaminant in the water such as turbidity, BOD/COD, dissolved solids and organophosphates (see figure 8.)
Water quality can also be inflected by seasonal or environmental effects. Does the water emanate from a single source (well, river or reservoir) or does it vary between several sources during the year? Are there any potential pollution sources that can influence the water quality or availability? What effect will a drought or service interruption have on water quality?
STEP 4: High-level TCO analysis will once more serve as the point of measurement for the holistic evaluations made during steps one, two and three. Similar to the analysis for air, the water assessment will seek to create a high- level baseline for evaluation and comparison. The financial and cost-dependent variables remain the same with cost of implementation, annualised operations and maintenance costs and associated energy costs being the most important to consider. The industry metric of IT refresh rate continues to be one possible point of comparison in determining the viability of the high-level TCO (see figure 7.)
The result from this exercise is that IT cooling needs must be assessed at a fundamental level that is not influenced by preconceived ideas or trend-setting influences.
Assessment must begin with an understanding of each installation’s assets and limitations and how this will influence your particular application. Stakeholders must be transparent in their attitudes towards risk and appraisal of how that risk can be mitigated or managed – from business, IT equipment and system performance standpoints.
Using air or water as the medium must be grounded in an understanding of resource access or delivery concerns, climactic limitations, quality or suitability and economic viability.
34
www.datacenterdynamics.com Figure 6: Air quality analysis Figure 5: Climate analysis
Figure 7: High-level TCO analysis
Figure 8: Water quality analysis
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56