Increasing energy efficiency with cooling and heating

HEATING AND cooling accounts for UK's and Europe’s biggest energy use and industry is the second largest energy user after residential sector. Implementing energy efficiency strategies to temperature control applications offers a significant potential to reduce that demand.

It is also the right thing to do. Decarbonisation of heavy industrial processes is central to reaching the Government’s target to achieve net-zero greenhouse gas emissions in the UK by 2050. With industry being the third-largest carbon contributor after energy production and transport, energy efficiency measures in industrial processes contribute to the decarbonization efforts, reduce costs across the system and improve the competitiveness of UK industry.

But where and how to start? While plant and facility managers might be intimidated by the task of cutting energy costs, the temperature control industry has been developing the tools, technologies and service offerings needed to meet this demand.

Let's look at several short and long-term actions that can be easily implemented, to start delivering more efficient systems that will reduce both carbon emissions and energy bills.

1. Designing the system. Energy efficiency audit

An initial consultation with experts ensures an informed start. Whether you’re considering a new cooling or heating system or planning to upgrade the existing one, working closely with a partner and expert capable to design or redesign your cooling and heating systems, one that could then remain as your service provider, is much more important than finding and purchasing the right chiller. Partnering with an industry expert opens the door to having the right equipment tailored to your needs and generates opportunities to enhance your temperature control process and HVAC systems.

To get a true picture of all areas that need to be addressed, by far and away the most comprehensive solution is to undertake an energy analysis audit. This can be carried out by a temperature control partner with good technical knowledge of your applications and temperature control equipment.

An energy audit records the existing energy use as well as usage patterns. It identifies opportunities for energy saving strategies, including technology replacements. Finding opportunities for energy, sustainability and efficiency gains in in case of chillers and temperature control equipment in operation isn’t easy, and decisions on what and how to improve need to be based on hard data. Audit will show the overall measurement results, analysis of these measurements and a proposition of enhancements to the chiller plant.

2. Free Cooling

Practically speaking, Free Cooling is the cheapest and greenest way to provide cooling. It allows businesses to reduce mechanical energy consumption, lower the carbon footprint, reduce load on mechanical parts and therefore reduce maintenance cost and extend life of your cooling equipment. In the case of a chiller, smaller load demands can also lessen the depreciation value of the unit over its lifetime. It is a solution that is easy to retrofit (space permitting) and can deliver a quick payback for the new equipment.

Practically any organisation using an externally sited chiller to cool their process can benefit from free cooling. Whenever the outside temperature is low enough to cool down the process fluid without the intervention of a chiller (mechanical cooling), we can implement a free cooling solution. This can be in the form of partial free cooling (where the chiller’s compressors are still doing some of the work to cool) to full free cooling (where the full load on the chiller is offset). In contrast, an externally sited chiller’s compressors with no free cooling capabilities will be working flat out to achieve the same.

Depending on the time of the year, as the ambient air temperature continues to fall, the amount of process heat taken out of the process fluid by the air increases, progressively reducing the load on the chiller. At 5 degrees Celsius below the process supply fluid temperature, all the process heat is removed by the ambient air in the free cooler – providing full free cooling. This makes free cooling the cheapest and greenest way to provide cooling.

In the UK, Ireland and much of Western Europe, the relatively cool climate and ambient temperatures allow for partial or full free cooling for much of the year. This means that substantial energy savings can be achieved particularly between the months of October and April, in some cases reaching up to 80% electricity savings.

3. Free Heating. Heating and cooling as part of the same equation

Something less obvious than Free Cooling, but equally effective, can be applied to the heating load. For analogy, we can call it “Free Heating” and heat pump is the technology that enables it.

While heat pumps were traditionally known for their residential applications, many industrial processes now look at heat pumps as an efficient heating solution for a wide range of their processes, recognising the economic and emission reduction benefits.

Heat pumps rely on one of the most energy-efficient methods of heating: the transfer of free thermal energy from outside to inside based on the difference in temperature between the two. What not everybody in the industry does though is look at cooling and heating at once. There are new opportunities ahead if we start looking at heating from the cooling perspective and the opposite.

Heating, cooling, heating while cooling, heating or cooling – we can make choices to satisfy heating and cooling demands in practically any application. Different heating demand profiles come with efficiency opportunities and allow for significant improvements by choosing the right heat pump solution – allowing also to combine it with other technologies.

While pure heating heat pump solutions require external (sustainable) heat sources such as air or (ground) water, combined heating and cooling applications provide the unique opportunity to reclaim or harvest energy which is available within the same plant or building. Chillers and cooling plant used to cool manufacturing processes and facilities generate waste heat that typically gets lost to atmosphere. This heat does not just have to be wasted and can be harnessed effectively by Industrial Free Heating (i-FH) units.

Over the last few years, innovations in process cooling and heating systems have led to innovative designs that can offer significant benefits compared to the systems that they are designed to replace.

With new generation, low global warming potential HFO refrigerants, it’s possible to achieve temperatures of even 120 degrees Celsius with water-sourced heat pump systems.

Energy efficiency, reliability, sustainability, options for customization and TCO all play a role in finding the right process heating solution that best fits your process needs. With technologies available at our fingertips to massively increase the efficiency of processes or buildings, we should not waste time to second-guess the opportunities we have.

4. Retrofit to VSD

When paying attention to your energy bills, it’s important to use technologies that maximize part-load efficiencies. Variable-speed technology is a cost-effective way to do this and should be taken into consideration not only when selecting a new unit, but also as a modernization effort of the existing system.

Controlling the flow of air and water in process temperature control systems is an effective, permanent way to meet the ever-changing demands put on a system and enhance its efficiency. By installing a Variable Speed Drive or VSD (an electrical/electronic system that provides infinitely variable speed control of AC induction motors) you can meet varying system flow rate requirements or just increase energy efficiency. Payback on an installed system can be as little as 6 months.

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 less, for a high Seasonal Energy Efficiency Ratio (SEER), a measurement of part – load efficiency. The result is lower annual energy use and typically smaller annual energy bills. This is especially true when compared to constant volume units, where the load is either on or off.

5. Be Flexible – benefit from easy upgrade to more efficient technologies

Innovation and new technologies usually bring increased efficiencies and other benefits to the customers. But today, organizations are focused on doing more with less, which also means counting every penny in their capital budgets to ensure the expenditure will provide the best return on investment. This applies to the temperature control systems in the same way as to any other element of the business.

When capex is an issue, the traditional alternative to capital investment in a way of purchasing and installing new equipment has been hire. But now there are more flexible options in the rental schemes. A membership or subscription type of a long-term rental agreement offers access to the latest process temperature control technology, maintenance, and equipment upgrades – all with the flexibility of an operating expense. This new subscription model allows manufacturers to transform their process temperature control system from a fixed asset into a dynamic solution that will be up-to-date with their changing business and process needs.

This type of a complete HVAC and process temperature control packaged solution includes new equipment vs. existing rental stock units, preventive and 24/7 emergency maintenance, replacements, and upgrades. The elements of the all-inclusive, monthly rate contract are tailored to the process’ needs and based on a detailed assessment by the service provider’s engineers.

Manufacturers receive the right temperature control solutions for their process needs with the flexibility to adapt their capacity according to changing seasonal and operational requirements. They get bespoke systems installed in their processes – with no upfront cost and capital investment. You only pay for the temperature control you need and when you need it.

Additionally, unlike in the case of a traditional long-term hire, they benefit from the flexibility to exchange and upgrade the equipment as their requirements change or technology improves. All this with the peace of mind of complete maintenance and contingency plans.

6. Planned preventive maintenance

The traditional approach to maintenance relies on a calendar or hour meter to determine when equipment is serviced. But technology gives us actionable information that allow performing maintenance when it is needed and not just because the schedule says it is time.

Preventative, predictive or reliability-centred maintenance uses testing, diagnostics and computer modelling to identify actual maintenance needs. This approach hinges on establishing a performance baseline for the temperature control systems based on the performance of similar systems. Systems are continuously monitored, and their actual performance is compared to benchmark data. As a result, it is possible to identify potential problems and schedule maintenance before they can cause systems to fail.

With their budgets under pressure, predictive maintenance is a good mean of controlling costs and reducing the likelihood of a temperature control system failure that could shut down your operations.

7. Remote monitoring services

Alongside a preventive and predictive maintenance approach, there are technologies and services available that allow you to have 24/7 access to live condition updates and the history of your assets, allowing you not only to oversee performance, energy consumption, but also remotely change set- points for better uptime, productivity, and efficiency. With these capabilities, you can combine data analytics, connectivity and expert support to maximise productivity, operational and energy efficiency of the heating and cooling systems.

Remote Monitoring Services enables remote technical performance and energy monitoring as well as thorough fault diagnosis, reducing unnecessary site visits and optimising maintenance operations. We calculate that with Remote Monitoring Service customers can reduce maintenance visits at their site by 50%, resolve even 75% of the issues on a first visit and by up to 55% reduce the operational expenses related with the temperature control equipment.

Remote monitoring technology incorporates internal watchdogs for performance verification and reliability of temperature equipment like chillers, boilers, pumps, air handling units and fan coils. It is also compatible with new and legacy equipment, rented or owned and works with customer’s building management systems.

By putting data to work, and pairing it with technical expertise, you can not only have full visibility of the units and expert support to optimise and maximise the equipment’s productivity, but you can also leverage this intelligence to better plan investments and resources to improve your business’ profitability and growth.

8. Water Treatment

Water treatment is the most forgotten service element in the chilled water industry but is also one of the most important ones for system’s reliability and its efficient operation. Most maintenance engineers know that if a chiller’s water and glycol mix is incorrect, the effects can be rapid and disastrous, leading to corrosion, system deterioration, and leaks, as well as the build-up of rust, scale, algae and debris. Chilled water needs to meet several criteria to be used as such. PH needs to allow the chemical makeup to remain stable and not create a chemical reaction.

This means that system-specific inhibitors need to be added for the metallurgy makeup of the system, system-specific glycol needs to be added for the type of process and biocides may also be needed and then monitored to suit a particular system issue. Whether its adding glycol, inhibited glycol, inhibitor and/or a biocide, each element has a benefit as well as a negative impact within a system and careful monitoring and dosing is necessary to ensure efficient and reliable operation.

9. Quality of chiller components – the EC fans

From an energy usage point of view, chillers are effectively comprised of two halves – high pressure and low pressure, and the closer those two sides are to each other, the more efficient the chiller. However, the quality of the components that make up a chiller can go a long way to improving the efficiency of a unit over the course of its operational life. One of the key components within a chiller that will impact performance and energy consumption are the EC (Electronically Commutated) fans.

EC fans operate using a DC motor rather than an AC motor, which in turn not only offers a much more efficient fan performance, but also lower noise levels. Engineers are often put-off by the investment in EC fans given the number of fans that can be found on a chiller. However, with a payback period of just 6-12 months, industrial end-users can start to make permanent energy savings from just the second year. If we add variable fan speed control, a further 12-14% energy savings can be made compared to standard on/off fan speed control.

10. Adiabatic cooling

The addition of adiabatic coolers offer a cost-effective alternative to a cooling tower by improving the carbon footprint and providing significant savings on water usage. These evaporative coolers are designed to operate at optimal efficiency in high ambient temperatures. The units use fans to operate the cooling for a high percentage of the year with a spray system which only activates during periods of high ambient temperatures.

The spray activity is tightly monitored using a pulsing mechanism to ensure minimum adiabatic cooling is provided for any given load and ambient condition. This control reduces water consumption and running costs for a long, fault free lifespan.

Adiabatic enhancements can be fitted to both new and existing air-cooled equipment. Without requiring energy to provide the cooling effect, the adiabatic enhancement can reduce the temperature of the ambient air by as much as 20°C. A reduction of 10°C alone can generate a 13% reduction in energy consumption – delivering immediate cost savings and environmental benefits.

Conclusion

Given the process-heavy nature of the UK's industrial landscape, getting a firm grip of a plant’s temperature control systems can quickly result in a reduction of energy consumption and consequently, utility bills. From upgrading the internal elements of a chiller to factoring free cooling or free heating technologies, this variety of tips and techniques will allow you to start taking back control of your site’s energy consumption and improving profitability.

Start by calling your temperature control partner and undertake an energy analysis audit to get a true picture of all areas that need to be addressed to improve your energy efficiency and reduce your overall costs.

Dave Palmer, general manager for the UK and Ireland at ICS Cool Energy

For more information: 

www.icscoolenergy.com

Tel: 023 8052 7300