The retrofit of aerodynamically designed high efficiency EC condenser fans can reduce chiller energy consumption by 10-20%.
Heat rejection is critical to chiller efficiency, most air-cooled condensers are compromised by both fan design and control, this reduces efficiency and increases energy consumption, particularly if low noise fans have been specified.
The replacement of existing AC fans with high efficiency EC fans improves airflow through the condenser, increasing heat rejection and energy efficient refrigeration, while overcoming many issues with operation at peak summer temperatures.
Typical condenser control is achieved by cycling fans on and off to maintain the required discharge pressure, this means that for example with a 4 fan condenser 2 fans could operate to achieve the required condition, however only 50% of the condenser is being utilised.
EC fans can be efficiently speed controlled from 0 – 100 % which allows all 4 fans to operate simoultaenously drawing air through the entire condenser while operating efficiently at low speed and reduced noise levels.
Many condensers also suffer from short circuiting, where hot air leaving the condenser is drawn back into the inlet, often caused by low noise fans or obstructions which prevent heat rejection. In extreme situations the temperature of air entering the condenser could be 10-15 deg c higher than the general ambient temperature, this effect will further reduce efficiency and often result in the chiller struggling to maintain the required temperatures during peak summer temperatures.
The aerodynamic design of replacement EC fans increases airflow while also projecting air further away from the condenser to overcome this short circuiting and improve energy efficiency, resilience and reduce costs.