Low-temperature district heating operations using heat cost allocators in apartment buildings

In the transition to Fourth-Generation District Heating (4GDH), buildings play a key role in determining the operating temperatures. Existing heating systems have the potential to operate at lower temperatures, as they are designed for extreme conditions that rarely occur. However, current space heating systems often operate with unnecessarily high supply temperatures, and there is no established methodology to quantify the possible reduction from the requirement of the building side.

The study proposes a data-driven method to determine the apartment with the highest relative heat load in multi-apartment buildings and then calculate the minimum required supply temperature curve based on heat cost allocation data and energy meter data.

The method was verified through simulations and validated in three Danish buildings over three years. All buildings successfully operated at the proposed level, maintaining indoor comfort with a supply temperature of 55 °C at an outdoor temperature of 0 °C. No occupant complaints were reported, and the indoor temperature sensors confirmed that indoor temperature was well maintained. The method offers a robust approach to prepare the building side for the transition to 4GDH.