Hot air behind your fridge – the future of (sustainable) cooling

Friday, July 13, 2018

By Jürgen Fischer, President of Danfoss Cooling and Member of Danfoss Group Executive Team

Picture this – you live in a hot and humid climate, and you get access to energy. What´s the first thing you buy to stay cool? Yes, an air conditioner (AC). As incomes and standards of living increase, so is the use of ACs in buildings around the world. As a result, the global energy demand for ACs is expected to triple by 2050[1]. The problem is people are buying ACs whose average efficiencies are less than half of what´s available on the market today[2]. To respond to the growing demand for space cooling we must, first and foremost, think energy efficiency.

Cooling appliances, such as ACs, consume energy, emitting heat while running. Anyone who has ever put their hand behind their fridge knows what I´m talking about. In turn, these heat gains add to air-conditioning demand. This dynamic, combined with the rising demand for cooling, pushes up power needs but also drives up CO2 emissions. Hence the need to think energy efficiency.

Sustainable cooling solutions

If I am being blunt, I have a crush on cooling. I am fiercely passionate about supporting the development of technologies that cool people, products, and the planet. The recent launch of a new International Energy Agency (IEA) report on The Future of Cooling[1] inevitably caught my attention. The IEA came out showing that cooling appliances account for about a fifth of the total electricity in buildings around the world – or 10% of all global electricity consumption. In a nutshell, cooling is the strongest driver of growth in buildings electricity demand and just 3 countries – India, China, Indonesia - contribute to half of it!

It’s thus crucial that we lead the way towards a sustainable cooling sector. And we must start today. We must follow a path that focuses on the best available technology and helps reduce the impact of cooling on energy demand and CO2 emissions. Smart energy solutions - district energy, thermal storage or heat pump technology - can combine heating and cooling cycles and enable other innovations, such as heat recovery. Combining cooling and heating synergies is a highly energy and resource efficient, and an affordable solution to help stabilize the wider energy system. Take the next two examples of solutions that do exactly this and are available today.

Looking into the future with heating 

Remember the ‘hand behind the fridge’ illustration? So, the cooling process produces heat. Traditionally, the heat is not used but instead released into the air. Heat recovery is an innovative process where we recover wasted heat and integrate it into the local energy system. This is a new and very attractive way to make the use of cooling more efficient.

Think about your local supermarket. A supermarket´s refrigeration system generates a lot of excess heat while they cool down your ice-cream and frozen pizza. With a heat recovery solution, supermarkets can instead recycle the heat and use it to heat up their own store or get hot tap water for free. For example, heat recovery from milk cooling systems can be used to pre-heat washing water giving energy savings of 60%. Otherwise, supermarkets can also sell the heat to the local heating plant and distribute it through district energy systems. In the end, heat recovery solutions can save energy for other uses and reduce pressure in the cooling system.

Buildings are part of the solution

And what if buildings could deliver more energy than they use? We already know the growing demand for space cooling calls for technologies that can maximize energy efficiency. But did you also know buildings offer the needed flexibility for more innovative solutions and can play a significant role in smart and integrated energy systems?

Yes, it´s true. We can change cooling demand by starting with buildings. District energy is a future-proof system - connecting electricity, heating and cooling, demand and supply, all while utilizing big data to foresee and level out system peaks to increase efficiency dramatically. The same supermarket that used a heat recovery solution, if integrated into the larger energy system, can unlock excess capacities that amount to 70% of a compressor’s cooling capacity.

But this kind of innovative, smart solutions, require collaboration and a collective mindset. All the technologies exist today, but they are mostly utilized in “silo” fashion. Unlocking the enormous synergies derived from true connectivity and collaboration can turn a problem into a solution. It can lead the way to smarter, more efficient energy systems all over the world.

Achieving efficient and sustainable cooling for all

Increasing the availability of energy-efficient cooling technology is the solution to avoid facing a “cold crunch”[2], as the IEA called it. And system thinking must be front and center of energy efficiency solutions. Integrating heating and cooling sectors can deliver huge efficiency gains. Cooling is not luxury – it is an essential part of our modern society. And if we manage to do it sustainably, we will also keep the planet cool.

Yet, if the technology is already available today – which it is - we need to call for governments to do more on efficiency. Policy interventions can also address the problems resulting from the growing demand for space cooling and can have a significant and rapid global impact. The right policy action is critical to ensure a sustainable path to the future of cooling and allow people to stay cool without straining energy systems or the planet.

Implementation and enforcement of efficiency standards for ACs and building codes that reduce cooling needs, are key to meet the world´s space-cooling demand in a sustainable fashion. The proof is the average energy efficiency of the stock of ACs worldwide could more than double between now and 2050[3]. But without strong regulatory measures, efficiency would still be 40% below that of the most efficient ACs on the market today[4]. The technology is available. From where I sit, only policy action can get us onto a much more sustainable track right now.

[1] IEA (2018) The Future of Cooling: Opportunities for energy-efficient air conditioning.
[2] IEA (2018) The Future of Cooling: Opportunities for energy-efficient air conditioning.
[3] IEA (2018) The Future of Cooling: Opportunities for energy-efficient air conditioning, pp. 66
[4] IEA (2018) The Future of Cooling: Opportunities for energy-efficient air conditioning, pp. 66