Chiller plants consume the most power of any component in a lot of buildings. Cooling demand accounts for typically 40-50% of those building’s total energy consumption. So it is important to pay attention to your chiller’s efficiency, as it can be both costly and wasteful. If you have an old or “standard” chiller – or if you have one that is not operating correctly – you might as well be throwing money out the window.
The most standard way of measuring chiller plant efficiency is based on “kW/RT”, or kilowatt hour per refrigerant ton. It is similar to the way we measure fuel economy of a car. The ratings km/l or mpg show how far you can drive per liter or gallon of fuel. If you have an electric car, then it’s defined as W/km.
The same methodology can be used for chiller plants, which consume electric energy (kW) to deliver refrigerant tons (RT) of the required cooling. So the lower the kW/RT, the more efficient your chiller.
As illustrated, the efficiency of chiller plants can range from anything between the good end of 0.5 kW/RT to the very bad 1.2 kW/RT. Having a new chiller plant is not necessarily equal to having high efficiency. Chiller plants need constant monitoring and adjustment to run optimally. Having an older chiller plant doesn’t mean that you have to replace the whole thing to become more efficient either. There is plenty you can do to optimize it and save money and CO2 emissions.