Improve Chiller COP with Eqobrush: Benefit from High ROI and Efficiency

An approach to calculate the advantage and estimate ROI

Improve Chiller COP with Automatic Tube Brushing System

EqoBrush Automatic Tube Cleaning Brushing System For Heat Exchanger

Eqobrush Automatic Tube Cleaning System

WATCO Group PTE ltd.

The transformative impact of Automatic On-line Tube Cleaning Systems for Heat Exchangers and Chiller Condensers in both industrial and comfort cooling (HVAC) applications is stunning. Online cleaning technology have demonstrated remarkable effectiveness in enhancing efficiency and conserving energy, by keeping the cooling water tubes clean from fouling to facilitate optimum heat transfer. Uncover the multitude of benefits and advantages of Automatic Tube Cleaning with the Eqobrush Tube Brushing system to improve Chiller COP, ensuring a high ROI and retrofittable to existing installations. 

Improve Chiller COP with Clean Condenser Tubes

The impact of Fouling on the Chiller COP

James E. Piper observes in his Industry Authority handbook: Operations and Maintenance Manual for Energy Management:

For example, a layer  of slime deposits only one one-hundredth of an inch thick (0.01” = 0.3 mm) on a chiller’s condenser tubes  raises the fouling factor by nearly 0.001 and causes the chiller to use approximately 10% more energy to produce the same amount of cooling.

Improve Chiller COP with clean condenser tubes
SEi vs COP
Introducing ClimaCheck's SEI as improved KPI

Limitations of COP as Chiller KPI

The chiller COP experiences a significant decline as the lift, the disparity between condenser and evaporator pressure, increases. Conversely, the SEI (System Efficiency Index), calculated by comparing achieved COP to Carnot COP, remains relatively stable across various operational conditions.

We advocate utilizing SEI as the primary Key Performance Indicator (KPI) for chiller evaluation and benchmarking purposes.

Note: Carnot COP refers to the theoretical maximum coefficient of performance achievable by a heat pump or refrigeration system.

Keep the Condenser Temperature low to Improve Chiller COP

Calculate Impact via plotting the refrigerant cycle on the Enthalpy Diagram

The Chiller COP (Coefficient of Performance) is defined as:

COP = Net refrigeration effect (kW) / Heat of Work (Compressor electricity use)

Plotting chiller operation data in the tool in the interactive p-h diagram (courtesy of demonstrates a loss in COP (loss in efficiency) of over 3.5% for each °C in condenser temperature.

If we assume that the heat load of the chiller remains unchanged (and the cooling water temperature remains unchanged), the loss in heat transfer effectiveness will eventually lead to an increase in condenser temperature.

The p-h diagrams demonstrate a negative impact of 7% on COP via a mere 2°C increase in condenser temperature that is caused by a minimal layer of fouling.


Calculate Chiller COP TLK-1
Improve Chiller COP with clean condenser tubes
Empirical method over Mathematical Approach

How to Calculate the Impact of Fouling in your project

Mathematically predicting the impact of fouling on condenser temperature is difficult due to nonlinear interactions between fouling, flow dynamics, and heat transfer. Fouling affects heat transfer coefficients and flow patterns, making accurate calculations difficult. Furthermore, fouling patterns and accumulation rates differ, limiting reliable predictive modelling.

A practical method for evaluating fouling impact entails measuring condenser temperature before and after cleaning intervals. This assesses the fouling effects and potential benefits of Eqobrush as an effective way to provide Chiller COP, facilitating detailed ROI assessment. Maintaining consistent running conditions during evaluation ensures precise comparisons and reliable results.