Free cooling uses cool ambient air temperatures to reduce the energy consumed by a cooling circuit as well as the electrical power load of a system.
Mr Metcalfe says: “The UK’s mild climate presents a significant opportunity for energy savings in process cooling applications via this method. Capital expenditure may put some industrial end-users off investing in free cooling systems, but the great news is that most systems offer a pay-back period of just 18-24 months.”
When it comes to refrigerants, end users have the opportunity to reduce operating costs and improve system efficiency while complying to current legislation, by opting for low global warming potential (GWP) refrigerants.
Mr Metcalfe explains: “The best example of this is that newer chillers, more often than not, incorporate screw compressors, meaning they can operate using the likes of R513A which is both non-flammable and efficient, and benefits from a much lower GWP than its predecessor, R134A.”
“The benefits of re-using excess heat from hot discharge refrigerant are undeniable, and include tangible efficiency savings, more comfortable working conditions and reduced environmental impact to name but a few,” says Mr Metcalfe.
“To access these benefits, end users must purchase equipment which facilitates heat recovery or retrofit an existing chiller of 250kW upwards with a heat recovery unit. With the latter scenario though, end users should consider the age and condition of the plant, as well as its thermal output and load profile, to ensure a healthy return on investment.”
Power factor correction
Power factor correction, which measures how effectively electrical power is converted into useful output, is often overlooked by industrial end users, despite its impact on energy efficiency.
Mr Metcalfe explains: “With a chiller, compressor efficiencies average a power factor of around 0.86 but many operate with a power factor as low as 0.81-0.82. Industrial end-users should target any areas with lower power factors and correct them to as close as 0.95 as practical to reduce on-going running current and, therefore, utility bills.”
Thinking outside of the box and adopting some lesser known techniques when it comes to improving the efficiency of temperature control equipment will quickly help industrial end users to take back control of their site’s energy consumption and improve profitability.
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