Katri Vala heating and cooling plant

Katri Vala is the largest heat pump plant in the world to produce heat and cooling. Its carbon dioxide emissions are 80% smaller than for example in separate heat production with heavy fuel oil.


  • What: heat and cooling
  • What from: purified waste water, return water from district cooling and electricity
  • Where: under the Katri Vala Park in Sörnäinen
  • When: 2006
  • How much: heat 126 MW, cooling 80 MW

Katri Vala

How heat pumps work

The heat pump operates on the same principle as, for example, a refrigerator.

Condenser (warm side) – The refrigerant is in liquid state in the condenser.

Evaporator (cold side) – In the evaporator the pressure is lower, which vaporises the refrigerant. The change in the state requires energy, which the refrigerant obtains by absorbing heat from its environment. That way, the temperature will fall.

Compressor – The pressure of the refrigerant is raised with a compressor, and this will make it return to liquid state in the condenser. At the same time, it will transfer energy as heat into its environment.