Illustrative c5 low delta t capacity
209 kW at the assumed low-rise flow ceilingmodeled
| Value kind | modeled — Interpret this value according to its displayed kind, scope, source, and as-of date. |
|---|---|
| Scope | Use 320 kW liquid IT duty, idealized water at 1.00 kg/L and 4.18 kJ/(kg·K), and the 10.0 K IT rise of 5.1. Assume an installed flow ceiling of 600 L/min and a useful rise reduced to 5.00 K at full heat. These inputs isolate the IT branch from the CDU auxiliary heat and illustrate the bypass/flow constraints described here. |
| As of | 2026-09 |
| Source | Guide calculation from expressly assumed teaching inputs. Primary reference supplies method or equipment context, not evidence that this design was built or tested. |
| Derivation | Required flow at 10.0 K is 459 L/min; at 5.00 K it is 919 L/min. At 600 L/min the reduced rise carries only (600/60) × 4.18 × 5.00 = 209 kW, leaving a 111 kW shortfall. Restore useful ΔT or change the qualified flow path before adding IT load. The crossover at 600 L/min is 320/[(600/60) × 4.18] = 7.66 K. At half heat, however, 459 L/min and 5.00 K carry 160 kW and are consistent; the issue becomes part-load pump energy rather than a capacity failure. Use 5.1 for the balance and 5.13 for the pump/system curve, with the ASHRAE CDU rating boundary keeping internal heat separate. |
| Review | checking…cadence-derived review 2027-01-03 · standard cadence |
| Recorded changes | none recorded |
| Claim id | p5-c5-low-delta-t-capacity |
Where the guide uses it
Not quoted in a chapter yet; it is kept in the curated register.
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