Is water quality important for system performance?

In water-cooled HVAC systems—especially high-capacity, long-running equipment such as Aurashu water-cooled screw chillers—water quality directly affects heat transfer efficiency, operating stability, maintenance frequency, and overall lifecycle cost.

A water-cooled screw chiller relies on two major water circuits:

Chilled water loop (supplying cooling to terminals or processes)

Condenser water loop (rejecting heat via cooling tower)

In both circuits, water flows continuously through heat exchangers, pipes, valves, and pumps. Poor water quality can lead to scaling, corrosion, fouling, and biological growth, all of which reduce system performance and may cause serious equipment damage over time.

Aurashu designs its water-cooled screw chillers for high-efficiency and long-term industrial operation, but even the most robust equipment requires properly managed water conditions to perform at its full potential.

(1) Reduced heat transfer efficiency

Scale deposits (calcium carbonate, magnesium salts) form insulating layers on heat exchanger tubes

Even a thin layer of scale can significantly reduce heat transfer

Chiller must run longer or at higher load → increased energy consumption

In Aurashu chillers, precision-machined shell-and-tube heat exchangers are designed for optimal thermal performance, but scale buildup directly offsets these advantages.

(2) Increased energy consumption

Fouled heat exchangers raise condensing temperature

Compressor power increases to maintain cooling capacity

System COP (Coefficient of Performance) declines

Over long operating periods, poor water quality can increase annual energy costs by 10–30% or more.

(3) Corrosion and equipment damage

Improper pH, high dissolved oxygen, or aggressive ions (chlorides, sulfates) accelerate corrosion

Corrosion can cause:

Tube leakage

Reduced pressure resistance

Refrigerant contamination

Premature heat exchanger failure

Aurashu offers optional anti-corrosion materials, tube coatings, and water-side protection designs, but correct water treatment remains essential.

(4) Biological fouling and blockage

Algae, bacteria, and biofilm can form in untreated water systems

Biofouling reduces flow area and heat exchange efficiency

Can cause unpleasant odors, hygiene issues, and system instability

This is especially critical in cooling tower condenser water systems.

Aurashu recommends managing water quality according to industry standards and project-specific requirements, typically including:

pH value (usually 6.5–8.5)

Hardness (calcium & magnesium content)

Total dissolved solids (TDS)

Chloride and sulfate concentration

Dissolved oxygen

Microbial content

Suspended solids

Maintaining these parameters within acceptable limits ensures stable chiller operation and extends service life.

Aurashu water-cooled screw chillers are engineered with water quality considerations in mind:

High-quality shell-and-tube heat exchangers

Optimized tube velocity to reduce fouling risk

Optional cupronickel, stainless steel, or enhanced copper tubes

Intelligent control system with temperature and pressure monitoring

Compatibility with standard water treatment and filtration systems

However, equipment design alone cannot replace proper water treatment.

For optimal long-term performance, Aurashu strongly recommends the following measures:

Water softening (to reduce scale formation)

Chemical water treatment (corrosion inhibitors, biocides)

Side-stream filtration (to remove suspended solids)

Automatic blowdown systems (for cooling towers)

Regular water quality testing and reporting

These measures significantly reduce maintenance costs and unplanned downtime.

Good water quality results in:

Longer heat exchanger life

Fewer tube cleanings

Reduced compressor stress

Stable capacity output

Lower total cost of ownership (TCO)

Poor water quality, by contrast, often leads to:

Frequent shutdowns

Emergency repairs

Reduced system reliability

Shortened equipment lifespan

For large commercial buildings, industrial plants, data centers, and hospitals using Aurashu chillers, water quality management is a critical operational strategy, not an optional extra.

Aurashu provides:

Water quality guidelines during project design

Coordination with EPC contractors and water treatment suppliers

Custom material selection for special water conditions

Operation & maintenance recommendations tailored to local water quality

This ensures that each chiller system delivers stable, efficient, and reliable performance throughout its lifecycle.