Huippuenergiatehokkaan asuintalon kaukolämpöratkaisut: District Heating Solution for Very-Low-Energy Residential Building

A number of prospective district heating solutions were investigated in the context of buildings needing 75% less energy as compared with standard solution today. Holistic approach was used, covering the entire system from room space, through the distribution piping, district heating substation to the district heating network. A district heating solution was proposed that fits very low-energy house. A number of different solutions were analysed from the life cycle cost point of view. The most cost-effective district heating solution was based on ventilation integrated heating. The solution included domestic
hot water system equipped with a storage tank connected through heat exchanger.
Conducted analysis suggests that district heating with traditional room heaters and current billing tariff structure may not be cost effective due to high investment costs. Present values (of energy and investments) of all investigated solutions projected over 30 years span remained within the range 0.23–0.33 €/m2 per month. The full load heat pump system was the most expensive and the ventilation integrated heating system using electricity with domestic hot water prepared by heat pump was the least expensive. The apparently narrow range band indicates that in addition to costs also other features should be considered when selecting the energy system. These could be e.g. achievability of high indoor comfort level, functionality, outlook of heating terminals.