Excavation for wastewater tanks has begun.
Two years ago, Norran reported (in Swedish) that Heimstaden and SBB had installed drain water heat recovery (DWHR) systems in the newly built residential area in Västra Erikslid.
HSB, a Skellefteå housing association is set to become the first to utilize this technology in an existing building by capturing heat from shower and dishwater drainage. The system recovers heat from wastewater, essentially recycling the warmth you have already paid for.
This initiative follows similar installations two years ago by Heimstaden and SBB, who focused on newly built residences in Västra Erikslid.
However, HSB is taking a pioneering step by implementing the system in an existing residential building – the Bostadsrätsföreningen Linden with 127 apartments, which is installing tanks specifically designed to capture heat from wastewater. The homes were built in 1960.
Here's how it works: Instead of flowing directly into municipal pipes, wastewater enters a tank where a heat pump extracts thermal energy. After the heat is captured, the cooled wastewater continues its usual disposal route. Wastewater with the highest heat content typically comes from showers. DWHR can reduce hot water requirements for showering by 40-60%. The system is most cost-effective for households with three or more occupants who use the shower more often than the bathtub.
How drain water heat recovery works.
Ann Åström, the association's chairperson, expressed her vision in a press release. "We believe this is the future," she stated, "and we aim to be a role model for other housing associations by demonstrating the effectiveness of drain water heat recovery."