Method
Daily and peak-hour hot-water demand aggregation over explicit usage rows.
Equations
Vday = Σ(n · qd)
Vph = Σ(n · qd · fph)
Symbols and units
| Symbol | Quantity | Unit |
|---|---|---|
| Usage rows: one row each | ||
| n | Quantity of units | no. |
| qd | Daily hot water per unit | L/unit/day |
| fph | Peak-hour factor | – |
| Results | ||
| Vday | Total daily hot water | L |
| Vph | Total peak-hour hot water | L |
Assumptions and limits
- Usage rates and peak factors are explicit row inputs; no defaults.
In practice
- Usage per unit and the peak-hour factor are project inputs; take them from the plumbing code or design guide your project follows.
Worked example
The input values are the calculator's own verification test, run through the calculator. They show the working; they are not design values.
Inputs
Usage rows
| n (no.) | qd (L/unit/day) | fph |
|---|---|---|
| 2 | 50 | 0.5 |
Results
| Vday | Total daily hot water | 100 L |
| Vph | Total peak-hour hot water | 50 L |
A preliminary check for engineer review, not an engineering approval. The project calculation to the applicable codes, authority requirements and specification governs.