A high-temperature heat pump developed in Finland is revolutionizing industrial energy production


A cutting-edge, energy-saving innovation for industry: new heat pump technology produces temperatures up to 130°C.

The high-temperature heat pump was unveiled at the Energia 2018 energy fair in Tampere, Finland.

Calefa has developed a high-temperature heat pump to meet industrial requirements. Using waste heat at 20-90°C, the high-temperature heat pump can efficiently generate temperatures up to 130°C. The heat pump can achieve a CoP (coefficient of performance) of 7, which means that 100 kilowatts of energy can produce 700 kilowatts of thermal energy.

The high-temperature heat pump is expected to revolutionize energy use within the process industries. For instance, it enables the energy-efficient and carbon-neutral replacement of low-pressure steam, which is widely used in the industry. Traditionally, steam is inefficiently produced using natural gas or oil.

Calefa’s high-temperature heat pump has been tested and run for 1.5 years in real district heating systems. The test results have been excellent.

- The high-temperature heat pump has proved itself reliable and performed very well throughout a long testing process. We have been able to efficiently produce up to 130 degrees of heat, says Calefa's Supply Chain Manager Petri Vuori.

More for less – and carbon neutral

Calefa Ltd. specializes in innovative solutions for re-using waste heat from industrial processes and power plants. These permanently decrease energy consumption. Emissions decrease with the size of the energy bill because energy that has been purchased once can be re-used multiple times.

Calefa’s solutions use heat pumps. The company has taken heat pump technology to a new level with regards to waste heat re-use systems. Heat pumps have previously faced the challenge of being unable to produce the high temperatures that industry requires. Apart from this, they have not been able to practically process high-temperature waste heat sources.

- Old units have been unable to generate more than 70°C. Heat sources over 35°C have already been too hot to handle. By developing heat pump technology we have found a cost-effective solution, says Calefa’s Managing Director Vesa Tamminen.

The heat pump was unveiled at the Energia 2018 energy fair in Tampere, Finland.

- The product has been received with great interest and enthusiasm. Discussions are being held with district heating companies and process industry representatives, says Petri Vuori.

The Finnish Patent and Registration Office has granted Calefa utility model protection for the connection of a high-temperature heat pump to the district heating network.




“Our intention is to concretely realize extensive action on environmental matters,” says Mikko Viljanmaa, vice president of Kiilto Oy, explaining the Finnish chemical giant’s growing investment in recycling waste heat.

Since the beginning of 2018, Kiilto has harnessed the waste heat produced in its adhesive production to heat the factory buildings on its three-hectare site in Lempäälä. The plant manufactures industrial adhesives products for the construction industry.

Kiilto had already been utilizing waste heat to warm the factory’s polymerization facility, but these benefits multiplied with the implementation of the new hybrid system. Recycled energy now heats almost all the factory buildings. This generates an annual saving of 80 000 euros in heating costs alone. Production was also improved by a cooling system that utilizes heat pump technology. The CoP for the heat pump in this facility is 4.

The hybrid system is a system that utilizes several different energy sources. Apart from waste heat, the heating and cooling in the Kiilto plant utilizes geothermal heating and cooling. Drilled geothermal wells in the bedrock act as a battery to store extra waste heat that can be reused in the future. The geothermal wells have been realized by Rototec Ltd. The refrigerants used in the production process heat pump and geothermal heat pump are R134a and R410a respectively.

The combination of geothermal heating and coolant pumps has given a significant additional boost to the cooling capacity of the plant, which has led to a subsequent improvement in its production capabilities. More importantly than anything else, Kiilto’s technical manager Vesa Juhannusvuori says that production plans no longer have to be adapted to accommodate the cooling capacity.

“Coolant water remains at a stable temperature during the entire process throughout the year, which improves the consistency of the quality of production,” says Juhannusvuori.

The hybrid system, which utilizes waste heat along with geothermal heating and cooling, is thought to be the only one of its kind in Europe, and probably also the whole world.

Despite being so new, the system has lived up to all its promises, starting with its energy-saving targets.

“Industrial heat recovery systems are extremely complicated, especially when they are connected to the plant’s production process. Everything has been working as it should,” Juhannusvuori says of the complete system that Calefa Ltd implemented

More than three hectares of industrial buildings are heated by 1800 MWh of recycled waste heat. Carbon dioxide emissions were at the same time reduced by 310 tonnes per year.

Success is inspiring

Success has inspired Kiilto to expand their utilization of almost free energy. Waste heat is always produced at the point of production but in the summer months, when there is a minimal need for heat, extra heat also remains unused in the factory area.

The hybrid system automatically guides waste heat to either the buildings, to storage in the bedrock or, as a final option, blows it out into the air. The goal is for the energy to be utilized as much as possible, so there is a continuous search for new recycling targets.  

One good target is water: heating the water with the hybrid system leads to an annual saving of 120 MWh.

“This is a relatively small addition to the old system but it is very useful, especially in the summer when there is no need for waste heat to be used anywhere else in the heating network,” says Calefa’s supply chain manager Petri Vuori with regards to the expansion.

A new angle on environmental issues

Environmental values are close to Kiilto’s heart. New targets where waste heat can be re-used and profitably exploited are constantly being mapped. Thanks to this project, Kiilto will decrease its co2 emissions to 310 tonnes per year.

“We have been systematically working to promote environmental issues since the beginning of the 1990s. Energy consumption in buildings and processes have been continuously mapped to find out where improvements can be made,” says Kiilto’s deputy managing director Mikko Viljanmaa.

Speaking about the recycling of waste heat, Viljanmaa says, “At some point it felt that we had run out of easy options. In that sense, it was really great that we discussed the matter with Calefa and found a new way to approach things.”

Finland’s northern location challenges its industry to continuously look for optimal solutions to energy consumption that do not affect the ability to compete while allowing energy to be used in an environmentally-friendly manner. Re-used waste energy is almost free energy.

The system that has been realized at Kiilto has demonstrated that we are on the right track. Hybrid energy systems open the door to a future in which waste heat can be re-used in conjunction with the use of other carbon-free forms of energy.

Utilization of waste heat

According to Statistics of Finland, industry uses 45% of Finland’s total energy use, buildings account for 27%, and traffic uses 15%. Motiva has estimated that 37% of the energy consumed by industry escapes into the environment as waste heat. Calefa Ltd. Estimates that 10-50% of the waste heat produced by industrial processes could be profitably recycled. The best results are obtained by using waste heat from the drying process.



Official Statistics of Finland (OSF): https://pxhopea2.stat.fi/sahkoiset_julkaisut/energia2017/html/suom0000.htm

Motiva: https://www.motiva.fi/files/8501/Tuotannon_hukkalampo_hyodyksi.pdf



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