How to Choose Fire Pumps for Multi-Zone Buildings

In multi-zone buildings such as high-rise towers, hospitals, malls, and industrial complexes, fire protection is more complex than in low-rise structures. The design and selection of fire pumps in these settings are crucial for ensuring that each zone—whether on the first or fiftieth floor—receives adequate water pressure and flow during a fire emergency.

As a leading fire pump manufacturer, we understand that choosing the right fire pump for a multi-zone building is not just a matter of flow and pressure—it’s about designing a system that remains operational, compliant, and efficient under challenging conditions. This article explores key factors, industry standards, and selection strategies for fire pumps in multi-zone buildings.

1. Understanding What “Multi-Zone” Means

A multi-zone building refers to any structure with vertical or horizontal divisions that require separate pressure zones due to significant elevation differences. This typically includes:

• High-rise residential and commercial towers

• Hospitals and medical centers

• Multi-level shopping centers

• Industrial facilities with varying elevation levels

These zones are created to manage the pressure differences in sprinkler and standpipe systems, since water pressure decreases as elevation increases.

2. Key Challenges in Multi-Zone Fire Pump Systems

Selecting fire pumps for multi-zone buildings involves addressing these critical challenges:

• Pressure Zoning: Preventing over-pressurization in lower floors while maintaining sufficient pressure at the top.

• Pressure Reducing Valves (PRVs): Required to manage pressure in lower zones but add system complexity.

• Water Supply Reliability: Ensuring that the pump can supply the needed flow and pressure even in peak demand or failure scenarios.

• Code Compliance: NFPA 20, NFPA 14, local fire codes, and insurance standards must all be met.

3. Step-by-Step Guide to Choosing the Right Fire Pump

Step 1: Conduct a Building Risk Assessment

Begin by analyzing the building’s layout, height, usage type, and fire risk profile. Ask:

• What is the building height?

• How many pressure zones are needed?

• Are there combined sprinkler and standpipe systems?

• Are water storage tanks on-site or are you relying on municipal supply?

This will help define the flow demand (GPM) and total dynamic head (TDH)—the two fundamental parameters for pump selection.

Step 2: Determine Flow Requirements per Zone

Each zone will have a unique required flow rate, depending on:

• Type of hazard (light, ordinary, or extra hazard)

• System type (wet or dry pipe)

• Connected devices (sprinklers, hose valves, hydrants)

For example, a standpipe system may require 500 GPM for the most remote outlet, plus 250 GPM for each additional standpipe, up to a maximum as per NFPA 14.

Step 3: Calculate Pressure Requirements

Vertical elevation greatly impacts the pressure a pump must provide. Use this formula:

TDH = Elevation Head + Friction Loss + Residual Pressure Requirement

• 1 meter = 0.433 psi

• For high-rises, each floor typically adds ~10 feet (3m) = ~13 psi

• Include loss in pipes, fittings, PRVs, and minimum outlet pressure (~100 psi for standpipes)

Example: A 30-floor building (~300 ft):

• Elevation head: ~130 psi

• Friction loss: ~20 psi

• Required outlet pressure: ~100 psi

• Total = 250 psi TDH

Your fire pump must be able to meet this pressure while still delivering the required flow.

Step 4: Decide Between One Pump or Multi-Pump Strategy

You can serve all zones with one large pump or divide them using multiple pumps:

Single Pump Strategy:

• One large fire pump with PRVs on lower zones

• Easier to maintain and operate

• Risk: failure affects the entire system

Multi-Pump Strategy (Zoned Pumping):

• One pump per pressure zone (e.g., low, mid, high zones)

• More reliable with redundancy

• Higher upfront cost and space needed

Tip: If zones exceed 275 psi, consider using pressure boosters or multiple fire pumps to manage the demand efficiently and safely.

Step 5: Choose the Pump Type

The most common fire pumps for multi-zone applications include:

Each has its pros and cons depending on your layout and pressure demands. Vertical turbine and multistage pumps are especially suitable for high-rise applications.

Step 6: Comply with NFPA 20 and NFPA 14

Always ensure that fire pump systems comply with NFPA standards:

• NFPA 20: Governs fire pump design, installation, and testing

• NFPA 14: Covers standpipe system requirements by zone

Key NFPA Requirements:

• Minimum 100% rated flow and 65% at 150% of rated flow

• Fire pump must start automatically in case of pressure drop

• Controllers must meet UL/FM or local authority approval

Also check with AHJ (Authority Having Jurisdiction) and local fire departments for additional compliance requirements.

4. Additional Components to Consider

A complete multi-zone fire pump system includes more than just pumps:

• Jockey Pump: Maintains system pressure to prevent false starts

• Diesel/Electric Motor Drive: Ensure backup power source

• Pump Controller: For automatic startup and shutdown

• Test Header: For routine performance testing

• Check Valves and Isolation Valves: To control backflow and system sections

• Pressure Gauges and Flow Meters: For real-time monitoring

Make sure the control logic supports sequential pump starting if using multiple pumps for different zones.

5. Importance of Factory Testing and Site Commissioning

Every fire pump must be factory performance tested per NFPA 20 standards. This ensures the pump delivers the rated flow and pressure.

Site commissioning involves:

• Checking suction conditions

• Verifying controller logic

• Testing all zones for correct pressure

• Simulating a fire event to monitor system response

Engage certified fire protection professionals during installation and testing for NFPA-compliant documentation and approval.

6. Maintenance for Multi-Zone Fire Pump Systems

Maintenance is critical, especially for high-rise buildings where downtime can endanger lives. NFPA 25 provides guidance for inspection, testing, and maintenance:

• Weekly: Visual inspection, controller checks, battery charge

• Monthly: Pump churn test

• Annually: Full flow test through test header

Ensure that each zone is periodically tested and that PRVs are recalibrated to maintain accurate control.

Conclusion

Choosing the right fire pump for a multi-zone building requires detailed planning, accurate calculations, and strict compliance with international fire codes. Whether you're designing a system for a new skyscraper or retrofitting an existing high-rise, the key is to balance pressure requirements, zoning strategy, pump type, and redundancy.

By working with experienced manufacturers like us, you ensure not only that your fire pump is reliable and code-compliant—but also that lives and property are fully protected when it matters most.