This report is based on the work I have done during my internship at Badeanstalten Spanien. I got aware of the massive amounts of hot water from the showers that just got led direcly into the sewers after use. This meaning a lot of energy is wasted on heating the water, so I decided to look at ways to use the energy from the used water to help heat the fresh water, before using the district heating.
The report is made of two main parts. The first part is about a European standard, that makes companies able to build a system to lower their energy consumption, by using excess energy to – as an example, heat water, instead of using district heating only. While working towards this, all directions will be reviewd, in order for a company to be approved.
In the second part, Badeanstalten Spanien's useage is reviewed and also other swimming pools, that have have gotten an installation to re-use the wasted water from the showers. Badeanstalten Spanien got closed in 2010 for improvements, and was closed for a year. This meaning that an overview of the consumption for a full year, have not been possible to make. An old overview can't be used, because of the showers being replaced with ones that is better for the enviorment.
In the report, two possible solutions on how an installation can be made, is discussed. These solutions are made in coorporation with two companies that got expertise in the field. In both, the installation is a pipe-in-pipe heat exchanger. The pipe-in-pipe means that in the inner pipe, the waste water from the showers flow, and in the outerpipe, new and fresh water that is on the way to the showers. This way, the heat from the waste water is used to heat the new and cold water.
The diffrence between the two installations, is that one is made by 32 copper pipes with a length of 2.1 meters, where the other is 4 pipes with a length of 6 meters, that is joined by u-shaped pipes, giving it a total length of 24 meters. The pipes in this is made by stainless steel.
At the end of the report, a messurement of how big the savings of the installations are calculated. These calculations are made from the companies that produces them, thinks their product can recover, what I belive the savings can be in theory, from the numbers that should be possible to achive. The numbers are taken from experience from a similar installation.
The conclution is that the installation can pay it self over a timespan of three to five years, by looking at the calculations.