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How green is your heat pump?

Right now, large investments are being made in green technology, and the demand for sustainable products is great. But it is not entirely easy to determine which products are truly environmentally friendly, when almost all are marketed as green. This is not least clear in the refrigeration and heating industry, where most products that are more environmentally friendly than boilers powered by fossil fuels are marketed as green. The environmental impact of heat pumps varies greatly, so our industry must set higher goals.

More people than ever are trying to reduce their carbon footprint, as they realise we need to be careful with our planet. But despite great efforts to reduce our carbon footprint, greenhouse gas emissions have never been greater than they were in 2019. It is then not easy to get an environmentally friendly production when almost all products are marketed as environmentally friendly, although they are really only a little better than old-fashioned technology based on fossil fuels.

Heat pumps are much better than boilers that run on fossil fuels

It is best if the heat pumps are powered by electrical energy from renewable resources. But even if the electrical energy is generated by power plants that are fired with fossil fuels, heat pumps have a much higher efficiency than the most efficient boiler with fossil fuels. This means significantly lower consumption of primary energy and lower carbon dioxide emissions into the atmosphere. In other words - electrically powered heat pumps consume less energy than solutions where boilers are used. This in turn contributes to reducing the heating plant's environmental impact.

Not all heat pumps are equally environmentally friendly

Thus, we see that heat pumps are a more sustainable solution than boilers powered by fossil fuels, but exactly how durable a heat pump is varies depending on the technology used. We can compare with the automotive industry. Electric cars are marketed as the solution to how the transport sector can reduce its carbon dioxide emissions, and of course electric cars - even if they are powered by a poor energy mix - are better for the environment than internal combustion engines for the transport itself. But one should be able to, without being an expert on electric cars; say that the environmental impact of car batteries varies greatly. Factors such as carbon footprint in manufacturing, the mixing of metals in cathodes and - not to forget - the transparency of the purchasing chain and waste management and recycling processes for batteries. So it is important that we do not just settle for a solution that is better than the internal combustion engine. This is something that the entire plumbing and refrigeration and heating industry must be seriously involved in - we must not settle for a simple solution just because it is better than boilers powered by fossil fuels.

TEWI (Total Equivalent Warming Impact) is a good measure

By using other techniques in heat pumps, we can influence the heat footprint of the heat pumps. To measure the difference between heat pumps, an index called TEWI (Total Equivalent Warming Impact) should be used.

When using TEWI, simulation of seasonal efficiency for the specific facility and specific climate regions is taken into account. Different heat pumps have different energy consumption if they are used in Italy or Sweden, for example. Energy classification with simulation of seasonal efficiency is much more accurate and relevant than measuring nominal efficiency, which is what is used for many stimulus and government programs.

Calculation for refrigerant greenhouse effect (GWP) is also included in the TEWI index. GWP shows how large an equivalent carbon footprint the refrigerant has (how many kilograms of carbon dioxide correspond to the greenhouse effect from 1 kilogram of refrigerant). The carbon footprint of the most widely used refrigerant in heat pumps today is 2,000 times higher than carbon dioxide. In addition, filling and potential leakage of refrigerant are also included in the TEWI measurement, as the environmental impact of the units increases the more refrigerant used.

In summary, it can thus be said that TEWI measures the actual greenhouse effect generated by the carbon dioxide footprint, both directly and indirectly and throughout its life - the lower the TEWI value, the smaller the carbon footprint of the heat pump.

A smart system is crucial for low TEWI

Modern commercial buildings often require simultaneous heating and cooling in different parts of the building. A multifunction heat pump or a liquid cooling unit with recycling function can move energy between areas in the building, which further improves the overall efficiency of the system and lowers its TEWI. But we must not be content with only evaluating individual products. The entire system must be taken into account when evaluating the carbon footprint. Therefore, it is crucial to use an intelligent control system that integrates and can demand-control liquid cooling units and heat pumps with, for example, air treatment units, circulation pumps and climate baffles in order to achieve a low TEWI value for the entire building.

Of course, Swegon focuses our development on achieving a low TEWI in commercial refrigeration and heating systems. The technology in these products together with advanced control functions will make it possible to maximize the efficiency of the entire system. It is not just the car industry that is changing rapidly towards more sustainable solutions - the same applies to plumbing and the refrigeration and heating industry. So check out our products and systems, and do not forget to work together to ensure the best possible environment, both indoors and outdoors.