2.1 Combination Central - Decentral

Heat distribution and temperatures levels

In this solution the higher temperature level for the DHW is provided by an additional (small capacity) heat pumps in each apartment. The central heat pump for the space heating (or for delivering the heat source for decentral heat pumps) can be optimized for lower temperature levels.

Size of building, number of apartments

This solution is suitable for all sizes of buildings with the preference for average and larger ones.

DHW and storage characteristic

DHW is produced separately in each apartment with a decentral heat pump. The heat distribution losses are significantly smaller than in case of a central solution. The size of DHW storages can by reduced. This solution allows an easier solution for the legionella issue. 

Energy standard, insulation level 

Depending on the final realisation of this solution, this concept can be used for buildings with any energy standard. The solution with a low temperature level for the heating and booster heat pumps for DHW is rather for buildings with a high energetical standard.   

Complexity of installation

Rather a complex solution, which requires higher number of heat pumps. Possibility for a convenient usage of outside air as a main source of the central heat pump using roof top heat exchangers (evaporators).

Heat Sources

For the main heat pump, all types of heat sources are possible. For the decentral heat pumps – exhaust air or the or the return water pipe of the space heating may be the heat source.

Specific issues of the concept

May be convenient as a solution for high-rise buildings. Using different temperature levels. Boosting of temperature possible.

Positive aspects

• Individual DHW
• High efficiency possible
• Smaller distribution losses

Negative aspects

• Higher investment