Condenser Water Pump Cooling Tower​

A condenser water pump (CWP) in a cooling tower system is the main circulation pump that moves heat-laden water between the condenser (chiller) and the cooling tower.

What a Condenser Water Pump Does

1. Draws cooled water from the cooling tower basin

2. Pumps it to the chiller condenser

3. Absorbs heat from the refrigerant inside the condenser

4. Returns hot water back to the cooling tower for heat rejection

It is a closed loop between chiller ↔ cooling tower, but open to atmosphere at the tower.

Typical Condenser Water Pump Flow Path

Cooling Tower Basin → Condenser Water Pump → Chiller Condenser → Cooling Tower Spray System → Basin

Common Types of Condenser Water Pumps

1. Horizontal Split Case Pump (Most Common)

* High flow, low head

* Very high efficiency

* Easy maintenance (top casing removal)

* Used in medium & large HVAC plants

2. End Suction Centrifugal Pump

* Compact and economical

* Small to medium systems

3. Vertical Turbine Pump

* Installed in cooling tower basin

* Used where NPSH is limited

* Common in industrial plants

4. Inline Pump

* Space-saving design

* Packaged chillers and rooftop towers

Typical Design Parameters (HVAC Systems)

Item	Typical Value
Flow rate	3 gpm per ton  (≈ 0.054 m³/h per kW)
Head	15 – 40 m
Water temp (in/out)	32–35°C / 27–30°C
ΔT (range)	5 – 7°C
Pump efficiency	80 – 90%
Motor	TEFC, IE3/IE4

Example Pump Sizing

500 TR chiller

* Flow = 500 × 3 = *500 gpm (≈ 340 m³/h)

* Select pump head based on:

 * Piping losses

 * Condenser pressure drop

 * Cooling tower elevation

Materials Commonly Used

* Casing: Cast iron / ductile iron

* Impeller: Bronze or stainless steel

* Shaft: Stainless steel

* Seal: Mechanical seal (carbon / ceramic)

Installation Best Practices

* Install pump below cooling tower basin water level

* Use suction diffuser or strainer

* Provide flexible connectors

* Include VFD for energy savings

* Avoid long suction piping to prevent cavitation

Common Problems & Causes

Problem	Cause
Cavitation	Low basin level, high temperature
Low flow	Fouled condenser tubes
Seal failure	Poor water quality
High power draw	Oversized pump

Condenser Water Pump vs Chilled Water Pump

Condenser Water Pump	Chilled Water Pump
Open loop	Closed loop
Larger pipe size	Smaller pipe size
Lower head	Higher head
Water exposed to air	Clean treated water