Booster Pump Sizing Guide

Booster pumps are required when available municipal water pressure is insufficient to meet building demand. Sizing involves calculating the pressure deficit at the design flow rate and selecting a pump that can deliver the required flow at the required head. Plumbing Booster's Pumps module automates this with imported Domestic Water demand or manual flow entry.

The Pumps module supports six canonical pump system types: 1. **Booster** — Pressure-deficiency analysis for buildings with insufficient municipal supply. 2. **Transfer** — Moving water between tanks or from source to storage. 3. **Hot-water recirculation** — Maintaining hot water circulation in domestic systems. 4. **Sewage** — Ejector pumps for sanitary waste, with basin and cycle-time sizing. 5. **Sump** — Groundwater or drainage collection with physical cycle model. 6. **Stormwater** — Pumping storm drainage from collection basins. Each type has type-specific fields, advisories, and calculation paths. The interactive tutorial covers a canonical booster-pump scenario; text lessons and video scripts cover the other types.

The Pumps module provides two friction-loss modes: - **Computed friction mode** (recommended): Uses a Hazen-Williams friction-loss engine with IPC Appendix E fitting equivalent-length data. Each fitting entry carries per-entry source provenance. The engine computes per-segment flow and associates fittings with their corresponding segments, producing an engineering-grade friction-loss breakdown. - **Manual friction mode** (fallback): The engineer enters friction losses directly. Use this when you have project-specific loss data or when computed mode is not applicable. The computed mode is traceable: every friction value can be traced back to the pipe material C-factor, segment length, flow rate, and fitting equivalent lengths used.

1. **Determine design flow rate** - From imported Domestic Water, Water Supply Tanks, or Drainage calculations, or manual entry. The governing scenario is the highest flow/head/worst duty. 2. **Calculate required pressure** - Fixture pressure (IPC Table 604.3) + static head + friction losses + safety factor. 3. **Determine available pressure** - Municipal supply pressure at the building connection. 4. **Calculate pressure deficit** - Required - Available. If positive, a booster pump is needed. 5. **Calculate TDH (Total Dynamic Head)** - Static head + friction losses + residual pressure + safety margin (default 10%, editable). 6. **Select pump arrangement** - Single, duty/standby (N+1), or multiple pumps in parallel. 7. **Generate system curve** - Plot system head vs flow to find the operating point.

The Pumps module can import duty points from other Plumbing Booster modules: - **Domestic Water** — Design flow and pressure requirements from pipe sizing calculations. - **Water Supply Tanks** — Tank refill flow rates and head requirements. - **Drainage System** — Stormwater and sump flow rates for drainage pump scenarios. When a source is linked, the duty point updates automatically when the source module's calculations change. This ensures pump selection remains consistent with the rest of the design.

- **IPC Table 604.3** - Fixture pressure requirements - **IPC Appendix E103.3** - Pressure analysis methodology - **IPC Appendix E** - Fitting equivalent-length data (with per-entry source provenance) - **Hazen-Williams equation** - Friction loss calculation - **ASPE Plumbing Engineering Design Handbook** - Pump selection methodology

A 5-story residential building: - Design flow: 40 GPM (imported from Domestic Water) - Required pressure at top fixture: 35 psi (flushometer) - Static head: 70 ft (21.2 psi) - Friction losses (computed mode): 15 ft (6.5 psi) - Total required: 35 + 21.2 + 6.5 = 62.7 psi - Available municipal pressure: 45 psi - **Pressure deficit: 17.7 psi (40.9 ft head)** - TDH with 10% margin: 40.9 x 1.1 = 45 ft at 40 GPM Pump duty point: **40 GPM at 45 ft TDH**. Select a booster pump or package meeting this duty. Note: The software reports **shaft horsepower** (water horsepower divided by pump efficiency), not motor horsepower. Motor selection requires consulting the manufacturer's motor efficiency and service factor data.

The Pumps module imports Domestic Water demand automatically. Select "Domestic Water" as the source in System Structure. The software calculates pressure deficit, TDH, and generates system curves. The Summary page shows the recommended pump family, arrangement, duty point, and advisory notes. A 10% design margin is applied by default and is editable. The governing scenario is automatically selected as the worst-case duty point across all scenarios.

Plumbing Booster performs **pump sizing** (calculating required flow and head) and **preliminary pump selection** (suggesting pump families and arrangements). It does **not** perform: - **NFPA 20 fire pump design** — Fire pump design requires a certified fire protection engineer and compliance with NFPA 20 standards. The software displays an advisory when fire-pump scenarios are detected. - **Pump product selection** — Final pump model selection requires consulting manufacturer performance curves, motor data, and project-specific constraints. - **Manufacturer-specific sizing** — Consult manufacturer catalogs for exact performance data, NPSH requirements, and warranty conditions. The software's advisories and disclaimers clearly distinguish between sizing, preliminary selection, and the engineering judgment required for final product selection.