Fennia office building, Helsinki
Type: Office, detailed studies
Summary: Retrofit of office building with high U-values. Ceiling heating/cooling panels, integrated to Sensus-system, were carefully dimensioned and positioned, resulting in good comfort and 25-35 % energy savings compared to tradition system.
The aim of the study was use radiant ceiling heating/cooling panels in a renovation project with relative high window and envelope constructions U-values. The ceiling panels were integrated to Sensus-system, which is developed by Are (one of the biggest HVAC contractors in Finland). The system suitability and possible energy savings were explored for system decision making.
In the Sensus-system the internal heat gains from the water based cooling panel network are used in AHU supply air heating with simultaneous free cooling effect to zones.
The system is controlled with developed special automation system with several control circuits and valves.
The challenge was to get comfort summer and winter time indoor conditions with none replaced windows (U=2.0 W/m2K, g-value 0.62) and fair and reliable energy use comparison between traditional system and Sensus.
More information about Sensus system
Special attention and care with heating/cooling panel sizing, panel positions in spaces and optimal panel surface area in order to fulfil indoor climate requirements. Avoiding extra costs of studied system with precise component dimensions and careful load simulations against manufacturer design data.
Modeled office building floor and nearest surrounding buildings causing shading to windows
Plant general view. Pipe connections were done with PMTMUX-objects within special macro
The energy savings were achieved mainly by the following improvements compared to the traditional system:
By proper dimensioning the required indoor climate conditions were fulfilled with the studied heating/cooling panel system. At some locations of the building with high windows water radiators were used instead/additionally with the panels, because of the high heating need. Water radiator network was already used/present because of secondary space use, so there was an existing network to connect the radiators.
Compared to traditional system Sensus system gave: