The European Heat Pump Association (EHPA) has awarded the fifth edition of its internationally coveted Heat Pump City of the Year prize. This year’s ceremony saw Calefa Oy win the award for a project in Mäntsälä, Finland.
The clearly defined objective of the project is to efficiently exploit the waste heat from a computing centre for district heating and to protect the environment. The process begins with heat exchangers which initially use the hot air extracted from the computing centre to heat water. Subsequently, the next step sees heat pumps in a district heating facility then raising the temperature of the water from 40 to 85°C. By doing this, 75% of the energy originally used can be reused. Not only is this process very efficient, it also protects the environment. In the first phase, it is estimated that CO2 emissions will be reduced by 4,000 metric tons per year and, upon completion of the project, this figure will rise to 11,000 metric tons of CO2 saved every year. Calefa’s precise role in this process is to ensure the entire technical conversion of waste heat into useful heat.
One notable feature of the project is that this is the first time such a large amount of waste heat from a computing centre has been directly exploited for district heating. The project requires particularly powerful and efficient heat pumps to increase the water temperature to 85°C. In this process, the heat pump system features 24 six-cylinder Ecoline compressors from Bitzer, which can each offer flow rates of up to 150 m3/h (at 50 Hz).
At this present moment in time, the heat pumps, which have a total capacity of four megawatts, supply around 1,500 homes with energy. This number is expected to rise to about 4,000 homes. As it stands, this system already complies with the environmental targets of 40% lower CO2 emissions as specified by the EU for 2030.
“We chose compressors from BITZER because they have stood for high quality, reliability and good performance for decades,” declared the CEO of Calefa, Vesa Tamminen. “That builds confidence where the long service life of the compressors is absolutely vital for us. We also know from experience that we can work together well with BITZER and can rely on their service. Our team have been successfully using BITZER compressors since 2007.”
The schedule for the project was very tight and challenging as work began in June 2014 and the system to recover the waste heat had to be completely installed by December. This deadline was reached thanks in no small part to the excellent cooperation between the operator of the computing centre (Yandex Finland), the district heating company (Mäntsälä Sähkö Oy) and the contractor (Calefa Oy).
Work has continued to progress well and the entire system is expected to go into operation in October of this year. Presently, the heat recovery unit in the computing centre has already been declared operational and can be connected to the heat pump system. The installation of the heat pumps commenced upon completion of the building work in the middle of June. The necessary pipework was also laid at this point in early June.
“We would like to offer hearty congratulations to all of Calefa’s staff on their great performance and their well-deserved award,” commented Ralf Gasper, the Director of Sales at Bitzer Northern Europe and Baltic States. “We are very happy about the confidence placed by Calefa in BITZER and that our ECOLINE compressors could contribute to the success of the project.”
