Credit to: PHI Press-release from 2.01.2014


Photo: PHI Monitoring confirmed efficiency in Passive House indoor swimming pool Lünen.

Experience with the “Lip – Bath” provides a good basis for follow-up projects.
With a Passive House indoor swimming pool, a few years ago the spa association Lünen broke new ground. Measurement data now demonstrate that courage has paid off: When energy consumption compared to other pools high savings were achieved – the heat demand as with electricity. The monitoring of the Passive House Institute also shows that during operation further optimizations are possible. The Pioneer Building in Westphalia, it’s making it an excellent foundation for future projects. In detail, the results can be found immediately in the online platform Passipedia.
Swimming pools are very energy intensive. Since many baths were built in Germany in the 70s, there is coverage rehabilitation needs. “The potential for savings is enormous – and the interpretation of data from Lünen clearly shows that the Passive House standard also is a viable solution”, –  Søren Peper, researcher says at the Passive House Institute. Hundreds of cities and Municipalities can exempt them from high operating costs.
Among the key points for achieving the Passive House standard also includes an indoor swimming pool with a thermal-quality building envelope, including windows. Thus, the comfort is not only increased, but the bath can be also operated at higher humidity, without causing condensate loss. Due to low evaporation, air humidity may also by the increased, the heating requirements of the bath be reduced.
Further savings are possible in the ventilation: The heat losses are reduced here by the use of high quality ventilation heat exchanger, and an appropriate ventilation control. When electricity demands provide lower air volumes and the use of efficient appliances for a significantly lower consumption. Improved swimming pool equipment with energy-efficient electrical systems and the reuse of filter backwash are further pillars of the concept.

The project in Lünen was scientifically supported from the start. In 2009 The Passive House Institute created this support by initiating a baseline study. The results were directly introduced into the planning. The main findings from this process, including first energy balances, were published in a report of the integral planning team. Then in September 2011 the “Lip -Bath” began operations – as a sports pool with five pools. More than a year, ending in March, 2013, the energy flows in the buildings were systematically collected and analyzed.
As usually in complex new buildings, the period of the measurements was still marked by the regulation of the building. The energy consumption values were still in the range of forecasts: based on the net area of  850 m² a heat reference of 1,189 kWh / (m² a) and a current reference of 718 kWh / (m² a). Nearly twelve percent of electricity consumption generated by solar systems.
In future, the final energy demand could be further reduced substantially in the “Lip -Bath”, especially by a plant for the processing of rinse water filter which was not in operation during most of the period of monitoring. Even when electricity demands, further savings can be anticipated. The pilot project is thus similar to the built about the same time “Bambados” in Bamberg that the efficiency of the Passive House a model for the future is also in swimming pools. The entire monitoring report and the studies which plan are available online through the knowledge platform Passipedia.

Entrance area of the new “Lip -Bath” with more than 200,000 visitors in 2012.

Photo: © PHI