Illustrative c5 buffer volume example
71.8 L required; 21.8 L additional effective volume for the stepmodeled
| Value kind | modeled — Interpret this value according to its displayed kind, scope, source, and as-of date. |
|---|---|
| Scope | Assume 60.0 kW extra heat for 10.0 s, no incremental rejection initially, idealized water density 1.00 kg/L and specific heat 4.18 kJ/(kg·K), permitted rise 2.00 K, and 50.0 L already participating at maintained flow. For the alternative assume rejection rises linearly from zero to 60.0 kW over the same interval. These are proposed waveforms and effective inventory, not measured response; they exercise 5.1 conservation under this chapter’s transport constraints. |
| 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 | With no incremental rejection, excess energy = 60.0 × 10.0 = 600 kJ. Required effective volume = 600/(4.18 × 2.00) = 71.8 L; additional volume = max(0, 71.8 − 50.0) = 21.8 L. Select added storage only if the actual tank supplies that effective contribution within the interval; this result does not qualify lost circulation. With linear rejection recovery, the excess-energy triangle is 0.5 × 60.0 × 10.0 = 300 kJ. Required volume is 35.9 L, so the existing 50.0 L suffices and added volume is zero. The crossover excess energy is 50.0 × 4.18 × 2.00 = 418 kJ; below it a new tank buys no required capacity. Demonstrate the imbalance and participation before choosing tankage over control changes. ASHRAE’s energy-balance boundary provides measurement context; 5.1 owns conservation and 13.5 accepts the installed transient. |
| Review | checking…cadence-derived review 2027-01-03 · standard cadence |
| Recorded changes | none recorded |
| Claim id | p5-c5-buffer-volume-example |
Where the guide uses it
Not quoted in a chapter yet; it is kept in the curated register.
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