A 5-Step approach to sustainable cooling - Count on Cooling

  • Home
  • A 5-Step approach to sustainable cooling

To provide sustainable cooling and minimise the aforementioned risks in the most cost-effective way, it is helpful to consider five distinct steps in the design and use of cooling systems. If these steps are fully implemented, the cooling systems will have minimum cooling demand, be highly efficient and be well integrated with the power generation system.

STEP 1 : Optimise the need for cooling

Optimising the cooling demand should always be the first step – in many cases it will lead to a smaller system being required and a significant reduction in energy use. Savings of 30% to 60% are often possible. There are numerous ways in which this can be achieved, for example:

  • Building design measures to reduce the thermal load, such as shading (savings up to 54%), high performance glazing (savings up to 29%) and improved insulation (savings up to 90%).
  • Improved control systems to avoid poor consumer habits such as “over- cooling”. For example, using a higher temperature set point for an air- conditioned building has the dual benefit of reducing the number of hours when cooling is needed and improving the equipment efficiency at times when cooling is required. Just a 1 degree C increase in set point can save 5% of energy use. Control systems also help to avoid cooling when no people are present in the room.
  • Doors on chilled retail displays can reduce the cooling demand significantly.
  • Designing data centres to operate at a higher temperature to reduce the energy needed for cooling.

STEP 2 : Improve the energy and resource efficiency of cooling equipment

There can be massive differences between the energy consumption of different cooling systems used for the same application. There are many potential reasons for poor performance, falling into 5 main areas:

  • Design: A state of the art design might use half the energy of an older design. Technologies such as variable speed compressors and optimised heat exchanger designs can deliver significant efficiency improvements.  Savings of 30% to 50% are often possible.
  • Sizing: Cooling equipment is often found to be oversized due to inadequate cooling load calculations, leading to inefficient operation of the equipment and increased energy use.
  • Control and operation: Modern control systems can ensure that the use of a cooling system is minimised and that the correct control settings are always used. Many inefficient systems have poor controls or the controls are not well optimised. Good controls are relatively inexpensive and might save 20% to 50% of energy use.
  • Maintenance: Over a period of time the performance of a cooling system can deteriorate due to a range of maintenance issues, such as fouled heat exchangers or refrigerant leakage. A good maintenance regime is essential to minimise energy consumption. Savings of up to 30% are typically achievable.
  • Monitoring performance: It is common to find that end users are unaware their cooling systems are operating inefficiently. Good instrumentation helps generate the savings possible through improved control, operation and regular maintenance.

A sustainable cooling approach requires responsible use of the natural resources used to produce the cooling equipment (for example copper, aluminium, steel, refrigerants, etc…). This includes the need to reduce, recover and reuse these materials, contributing to a Circular Economy approach. Heating and cooling products are subject to different Regulations (e.g. in the EU: Ecodesign, RoHS, WEEE), and therefore contribute to Circular Economy across their whole lifecycle, for example:

  • End of life: Heating and cooling products are not allowed to be disposed of by consumers directly, but only by professionals and installers that ensure proper handling of all materials.
  • Extended Producer Responsibility (EPR): Significantly improved end-of-life recycling techniques that enhance material recovery.

STEP 3 : Mitigate the climate impact of refrigerants

The direct impact of refrigerants can be minimised by a combination of various factors, such as:

  • The GWP of refrigerants: When new equipment is being purchased the “traditional” high GWP HFC refrigerants should be avoided. In the EU, the F-Gas Regulation has already led to the availability of lower GWP alternatives in almost all parts of the refrigeration, air-conditioning and heat pumps market. The Kigali Amendment of the Montreal Protocol will lead to rapid uptake of lower GWP alternatives throughout the world.
  • Proper installation, maintenance and servicing, by working with qualified installers
  • Set up of refrigerant recovery and recycling schemes to avoid that refrigerants are emitted into the atmosphere during servicing or at end-of-life.

STEP 4 : Address the investment cost for higher efficiency solutions

In most countries there is little or no interaction between decisions made to purchase cooling equipment and decisions affecting the supply of electricity. If end users continue to select inefficient cooling appliances, for example because they have the lowest capital cost, there will be unnecessarily high peak electrical demands created. These must be met by building extra power stations and by creating larger electricity transmission and distribution networks. Working in this way leads to:

  • Unnecessarily high electricity use and cost to the end user.
  • Further extra cost, as the price of electricity will need to reflect the excessive peak demands created by the widespread use of inefficient appliances. Ultimately these extra costs must also be paid by end users.

To overcome this issue, there needs to be close cooperation between the parties involved, to create a more integrated approach to the delivery of more cooling and to optimise the balance of capital investment between new cooling equipment and power generation. 

By encouraging end users to only use the most efficient equipment, the overall cost to the country or region can be minimised. This type of integration can be considered in a number of different ways:

  • By ensuring that cooling appliances meet high standards of efficiency, for example by using Minimum Energy Performance Standards (MEPS).
  • By informing users about the energy efficiency differences between products offered on the market, for example by Energy Labels.
  • By supporting buyers to overcome the financial challenge of a higher investment cost, for example by offering different types of financing schemes or incentives.
  • By incentivizing power supply companies to support investments in high efficiency cooling.
  • By facilitating it for end users to “sell” the waste heat from their cooling equipment to other users that require heating. For example, supermarkets could sell their rejected heat to a district heating system.

STEP 5 : Shift to renewable energy sources with an integrated approach to cooling and heating of individual buildings or whole cities

To maximise the cost-effective uptake of renewable energy it is important to integrate the design of energy supply systems (supply side) with the design of energy using systems (demand side). This means, for example, that buildings need to be considered as a key element of the energy infrastructure with heating and cooling demand being at the core of long-term planning.

An important opportunity is to ensure optimal use of energy between different categories of users (residential/commercial/industrial), by coordinating building clusters at local and at city level. Such an approach enables the provision of minimal energy input, without sacrificing the functionality of the system (whether dedicated to comfort, manufacturing processes, or other functions).

Examples for system integration include:

  • District heating and cooling systems for individual large buildings, building clusters or whole cities, enabling the development of highly efficient cooling systems operated with low carbon energy and optimised with sophisticated technologies such as energy storage.
  • Decentralised systems such as heat pumps or photovoltaics to relieve burden from the electricity infrastructure, while guaranteeing delivery of energy without interruption, thus increasing supply reliability.
  • On-site energy storage where cold (and heat) are used as thermal energy batteries and demand response schemes, where heating and cooling systems provide flexibility to the grid and shift peak demand which is increasingly important with the transition to renewable energies.
  • Integration of decentralized systems into thermal networks empowering consumers to help share cooling and heating capacities, be it on a local level or on the level of building clusters. Again, this can be a great opportunity to increase efficiency and flexibility while reducing investment in large central heating and cooling plants.
  • Integration of decentralized systems into thermal networks empowering consumers to help share cooling and heating capacities, be it on a local level or on the level of building clusters. Again, this can be a great opportunity to increase efficiency and flexibility while reducing investment in large central heating and cooling plants.