Method
Total dynamic head as the sum of supplied head components; friction is not calculated here.
Equations
H = Hst + Hf + Hfit + Heq + Ht + Ho
Symbols and units
| Symbol | Quantity | Unit |
|---|---|---|
| Inputs | ||
| Hst | Static head | m |
| Hf | Pipe friction head | m |
| Hfit | Fittings head | m |
| Heq | Equipment head (coils, heat exchangers, chillers) | m |
| Ht | Terminal head (control valves, terminals) | m |
| Ho | Other head | m |
| Results | ||
| H | Total dynamic head | m |
Assumptions and limits
- Negative static head is permitted when geometry supports it.
In practice
- In a closed loop the static lift cancels between supply and return, so the static head is zero; it counts in open systems. Friction is worked out separately and entered here.
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
| Hst | Static head | 12 m |
| Hf | Pipe friction head | 8 m |
| Hfit | Fittings head | 3 m |
| Heq | Equipment head (coils, heat exchangers, chillers) | 5 m |
| Ht | Terminal head (control valves, terminals) | 4 m |
| Ho | Other head | 0 m |
Results
| H | Total dynamic head | 32 m |
A preliminary check for engineer review, not an engineering approval. The project calculation to the applicable codes, authority requirements and specification governs.