Demonstration of an innovative 2-pipe active beam system
Development of an innovative 2-pipe active beam system for cooling and heating of buildings
has been finalized with support from PSO-2013. The system fulfills expectations.
In this project the system will be demonstrated in use in large scale in an office building with
many floors and many rooms with different use.
In a PSO-project (345-010) requirements and conditions for a 2-pipe active beam system for
cooling and heating of office buildings are layed down. The advantages of a 2-pipe active beam
system are that the energy use for pumps are halved and overall fewer components are required.
This result in lower costs for installation and more simple regulation of the system. The 2-
pipe system differentiate from 4-pipe systems as the temperature levels of supply and return
water temperatures are close to room temperature thus a greater part of the year there is no
need for cooling and heating.
The PSO-project have shown that the system is able to provide heating and cooling as a 4-pipe
system but with 10-15 % lower energy requirement due to the direct transfer of heating and
cooling between rooms. Further reduction of energy requirement can be reached through the
use of free cooling.
In PSO-project applied for here, the developed system will be installed in a new office building.
The object is to demonstrate the performance of the system in different rooms with different
use and analyse the energy reduction compared to a traditional 4-pipe system.
The building, where the system is installed, is in 16 storeys and comprise mainly offices but
there are also meeting rooms, restaurant and gym. In each storey 36 beams will be installed,
thus in total about 600 beams will be installed.
This project aimed at analyzing the full-scale operation of a novel two-pipe system, which was installed for the first time in a real building in Jönköping, Sweden. Aspects such as indoor climate and energy performance of the system were investigated.
Generally, it can be concluded that the two-pipe system is able to maintain a quite constant thermal environment in the space throughout the year (22 °C ±1.5 °C), without the use of any feedback controller. No significant vertical air temperature difference was noticed, and the draught rate was below 10% for most of the cases.
Occupants in the building were satisfied with the thermal conditions provided by the two-pipe system. In winter, 71% of the respondents to the questionnaire provided an answer related to a state of thermal comfort. In summer, 92% of respondents replied to be in a situation of thermal comfort.
In terms of operation and energy use, the two-pipe system operates as designed. The supply water tempera-ture was in the range of 23.4°C (winter) to 19.6°C (summer). Heating and cooling annual energy use were 27 kWh/m2 and 15 kWh/m2, respectively.
In conclusion, the two-pipe system represents a valuable alternative to conventional four-pipe systems in office buildings. Besides annual energy saving for heating and cooling, the design of the two-pipe systems allows to save installation cost due to the need of only one water circulation pump, fewer pipes and no control valves.
Thanks to the results provided during this project, the two-pipe system is currently being installed in two other office buildings located in Jönköping. Lindab A/S is also investigating possibilities to install the two-pipe system in Denmark.
This project also resulted in the initiation of a new ELFORSK project (350-013 Energibesparelse til komfortkøling ved anvendelse af PCM i 2-rørs-kølebaffelsystemer), which aims at developing a novel PCM-based heat exchanger that will be able to significantly reduce the cooling energy use of the two-pipe system.
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Lindab A/S |
