City of Mäntsälä

Project manager: Mr Vesa Tammienn

Project’s name: Combined Data and Heat

Project details: 

  • The project will in its first phase, provide heat for about 1500 households. The final target is to heat 4000 households.
  • The project is a good example of successful multi partnership: where the city of Mäntsälä use of waste heat via district heating, Yandex datacenter is willing to provide their waste heat and Calefa was selected to deliver the suitable heat recovery and heat pumps systems to fulfill the needs.

Technically the project is built in two main part:

  1. First part are the heat exchangers at Datacenter to convert the heat present in exhaust air into liquid.
  2. Second part is the district heat power plant (CDH) where the heat pumps rise the temperature level up to +85C.
  • The CDH system is connected to the district heat network and its control system. The CDH heat is always used as much as possible. It is estimated that even in the first phase it covers the total heat demand during the summer season.
  • The heat exchangers are designed to optimize pressure drop and heat exchanging.
  • The heat pumps are optimized for high COP and high temperature. The total power of almost 4 MW in first phase led in using R134a as refrigerant with reciprocating compressors. This enabled a long term, safe and high COP solution.
  • The role of the heat pump is crucial for this project. The temperature coming out from datacenter is about +40C which is too low to be utilized.
  • 75% of the district heat is origin from absolute clean source.
  • The reduction of CO2 emission in district heat will be in first phase 4 000 tons / annual and in the final phase about 11 000 tons. The need of natural gas is reduced dramatically.

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