The chiller, recirculating pumps, and fans are the main energy consumers in water-cooled air conditioning systems, and chiller efficiency can have a significant impact on the amount of energy required to produce a ton of refrigeration. Effective water treatment keeps the evaporation and condenser heat exchange surfaces clean and corrosion-free. That means the water is flowing and heat is transferred such that the chiller is optimally efficient and energy costs minimized.
The chiller transfers heat absorbed from the building by the chilled water system to the cooling tower, where it is dissipated into the atmosphere. Thus, deposits that interfere with this process need to be minimized. Scale deposit buildup also inhibits the compressor, which is designed to work within a certain pressure range for a given load, creating the conditions for “high head pressure,” which causes the compressor to work harder.
Even a 1°F increase in refrigerant temperature will cause the compressor to consume 1.5% more energy. Scale deposit thickness of only 0.05 inches reduces efficiency by 45% and can massively increase annual electricity costs. Biofilm (slime) deposits result in even greater reductions in efficiency and thus greater costs. And with a thick enough deposit of either (or both), condenser head pressure can exceed limits—and the chiller will shut down.
Clearly, then, not all deposits are created the same. Slime deposits are actually the most problematic. Calcium carbonate scale transfers heat up to four times better than slime, so slime is more likely to shut down a chiller than scale. Of course, condenser deposits can also be a mixture of slime, scale, corrosion byproducts, and even suspended solids scrubbed from the air.
Effective water treatment that eliminates scale buildup and provides good microbiological control is vital for efficient chiller operation. Both pressure and costs can be decreased by keeping the evaporator and condenser heat exchange surfaces clean and free of corrosion.
A customized water treatment program from Chem-Aqua does more than just protect your cooling water system from the ravages of corrosion, deposits, and microbiological growth. It helps maximize the life, efficiency, reliability, and safety of your cooling water system while keeping energy, water, and maintenance costs to a minimum. Chem-Aqua provides innovative and effective treatment technologies for all types of cooling system designs and applications, including open recirculating systems, closed loops, and once-through systems.
Since 1919, Chem-Aqua has provided custom-designed programs that solve water treatment problems and make boiler, cooling, and process water systems more efficient. Our success is built on our Total System Approach to water treatment. Long ago, we recognized that good results require a comprehensive program of products, equipment, and services that address the unique mechanical, operational, chemical, and human requirements of each system.
To learn more about the impacts of water treatment in chiller energy costs, visit our website today!