Cooling configuration accuracy and design guidelines
Cooling configuration accuracy
The Potential Flow Models (PFM) used in this application are typically within about 10% of CFD for Capture Index, Average Rack Inlet Temperature, and perforated tile airflow; they are not as good at predicting maximum rack inlet temperatures.
Cooling design guidelines
For the most efficient cooling design, equipment should be placed in clusters. An equipment cluster is two nearly-equal-length rows of equipment separated by a hot or cold aisle. A row of equipment can be a member of one or two clusters.
All heat generating equipment (racks and UPS) properly positioned in rows will show up color-coded in the Floor layout. However, you will experience better cooling performance with well formed clusters:
- All rows are of similar length and aligned across hot or cold aisles.
- The equipment rows do not include blocks, gaps, or spaces.
- In Hot Aisle Containment Systems (HACS), cooling units are positioned in pairs directly across from each other.
Example: Well formed cluster
Cooling performance predictions, which assume the racks are populated evenly, will be more accurate if racks are populated in bottom-to-top order and for more regular room shapes and well-formed hot/cold aisle layouts.
If you flip a row to face front to back, it affects the cooling simulation for up to 3 rows.
Cooler airflow specifications
Cooler airflow in cubic feet per minute (CFM) is assumed to be:
InRow RC (300 mm)
InRow RC (600 mm)
InRow RP (600 mm Chilled Water)
InRow RP (600 mm Air Cooled)
InRow RD (600 mm Air Cooled)
InRow RD (300 mm Air Cooled)
InRow RD (300 mm Fluid Cooled)
- Rack airflow is by default assumed to be 160 CFM/kW based on the total rack power. This value can be changed by right-clicking a rack and selecting Properties, to change to, for example, 105 CFM/kW for blade server racks.
- CRAC airflow is, by default, assumed to be 6000 CFM. This can be changed by right-clicking a CRAC and selecting Properties.
- UPS airflow is automatically calculated by the system based on the UPS size and the number of power modules (assumed to be 10kW each).
- Airflow through each tile is calculated as the tiles are positioned in the layout.
- Airflow for generic powered equipment is not included in the cooling calculations by default. This can be changed by right-clicking a piece of generic powered equipment and selecting Properties.