Reducing energy consumption in process cooling is on the agenda for manufacturers looking to save money on their energy bills. The same strategy can also help them improve the reliability and resilience of their operations and remain competitive in the local and global marketplace.
The UK manufacturing sector is also subject to a range of environmental and sustainability regulations, which impact how industrial facilities operate, their carbon footprint and sustainability goals. The target to achieve net-zero greenhouse gas emissions by 2050 requires significant reductions in emissions across all sectors, including manufacturing. With heating and cooling accounting for the UK’s and Europe’s biggest energy use, implementing energy efficiency strategies to temperature control applications offers potential to reduce that demand.
Part-load performance
However, manufacturers thinking about improving the efficiency of their cooling systems and lowering their energy bills should consider technologies that maximise part-load efficiency. This matches output to demand, rather than systems that operate at one speed regardless of the cooling load. Constant volume cooling systems consume the same amount of energy, whether the cooling load is high or low.
By contrast, installing a VSD – an electrical/electronic system that provides variable speed control of AC induction motors – allows users to meet varying system flow rate requirements or just increase energy efficiency.
Variable speed components meet the actual load required during any given time over a wide operational range, meaning their speed and output varies to reflect the conditions and demands. By precisely matching output to the cooling demands, compressors and fans operate at their fastest levels when demand is high, and modulate to slower levels when demand is lower, for a high seasonal energy efficiency ratio (SEER), a measurement of part–load performance. The result is lower annual energy use and typically smaller annual energy bills.
For example, a cooling system with a fixed-speed motor may consume 100kW of energy, regardless of the cooling load. In contrast, a cooling system with a VSD motor may consume only 60kW of energy when the cooling load is low, and up to 90kW of energy when the cooling load is high. This results in energy savings, reducing the overall operating costs and improving the system’s efficiency.
In addition, VSD technology can increase the lifespan of the cooling system. Constant-volume cooling systems operating at a fixed speed place a constant strain on the motor and other components. Over time, this can result in wear and tear, leading to breakdowns and increased maintenance costs.
RETROFIT TO VSD
Generally, variable-speed technologies are used by chiller manufacturers across product portfolios, but they can also be retrofitted to existing chillers, making them an option for businesses looking to improve the efficiency and reduce the energy consumption of their cooling systems.
Retrofitting VSD technology to an existing chiller involves installing a VSD between the motor and the electrical supply. The VSD adjusts the motor speed to match the cooling load, reducing energy consumption and costs. Payback on an installed VSD system can take as little as four to six months.
Matching the right VSD to the application requires an understanding of the chiller’s cooling load, including peak and off-peak periods, as well as the chiller’s existing control system to allow for proper communication between the VSD and the chiller’s other components. Those interested can consult with industry professionals to assess the chiller’s existing system and make recommendations about retrofitting VSD technology.
Once the VSD is installed, it is essential to monitor and maintain the system to ensure optimal performance. Regular maintenance with a qualified professional can help identify issues before they become problems, reducing downtime and maintenance costs.
Also, getting a grip on a plant’s temperature control systems can reduce energy consumption and utility bills.
If VSD technology seems like an interesting option, companies can speak with their temperature control partner and undertake an energy analysis audit to understand how to improve their energy efficiency and reduce costs.
THE RENTAL OPTION
Today’s market often requires companies to be conscious of the money available in their budgets to ensure expenditure will provide a return on investment. When considering energy efficiency upgrades to temperature control systems and restrictions on capital expenditure budgets are an issue, companies can opt for a subscription rental agreement.
This model allows users to keep their process temperature control system up to date. They receive new equipment rather than existing rental stock units, plus preventive and 24/7 emergency maintenance, replacements and upgrades. The elements of the all-inclusive, monthly rate contract are tailored to the process’s needs and based on a detailed assessment by the service provider’s engineers.
Industrial cooling users can also adapt the capacity of their temperature control solutions according to changing requirements. They get bespoke systems installed with no up-front cost and capital investment, as well as the ability to exchange and upgrade equipment.
BOX: NHS TRUST MAKES GREEN INVESTMENT
In northern England, ICS Cool Energy retrofitted and decarbonised a heating system run by Hull University Teaching Hospitals NHS Trust with heat pump and multi-pipe chiller technologies.
The hospitals’ decarbonisation of heating project involving switching from gas fired boilers to renewable sources of heating. It is part of their Zero30 commitment to be carbon neutral by 2030.
Commissioned in October 2022, the Hull Royal Infirmary’s new heating system is based on an ICS Cool Energy multi-pipe Aptus chiller and an i-FH heat pump.
For the hospital, maintaining the right temperature, humidity, and air quality is essential to ensure comfortable and healthy conditions for patient care and staff comfort, all day and all night.
The existing heating plant, which served two wards, office areas and seven operating theatres in the Hull Royal Infirmary was based on 650kW gas boilers that were designed for a return hot water temperature of 80°C. This temperature range was also one of the main requirements for the new, environmentally friendlier technology.
The installed ICS Cool Energy Aptus multi-pipe unit offers simultaneously up to 574kW of cooling and 695kW of heating from mains electricity. Its capacity enabled shifting from a separate boiler and chiller to one single unit, reducing both operational costs and saving on energy. Featuring two completely independent water circuits, the unit ensures precise temperature control for both chilled and hot water. For the production of hot water, the unit uses renewable and recovered energy, and can replace the existing fossil-fuel boiler and chiller system to deliver both cooling and heating for the building with no direct greenhouse gas emissions.
To boost the hot water temperature to the 80°C levels desired by the hospital, the multi-pipe chiller was paired with the 429kW i-FH water-to-water heat pump. The i-FH can deliver hot water between 50°C and 80°C, with source temperatures from 5°C to 30°C.