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Energy from wastewater
Use wastewater heat for heating-cooling-hot water!

Energy from waste water for heating and cooling of buildings!

Technologies for the use of energy from wastewater are economical, efficient and highly innovative solutions – absolutely at the pulse of time! More than 50% of the world’s energy requirements are used for heating and cooling, including hot water preparation. With the heat of wastewater, we have a huge energy potential at our disposal, which can be used with state-of-the-art heat exchanger and heat pump technology – economically, efficiently and innovatively!

Sewer waste heat heats and cools buildings

If office and residential buildings, hospitals or shopping centers are located near canals with a waste water volume of at least 10 liters per second, these buildings can be heated and cooled with the energy from the wastewater in a particularly economical and environmentally friendly manner. Innovative heat exchanger systems and efficient heat pumps are used here, which significantly reduce energy costs and CO2 emissions for systems with an output of more than 100 kW.

With our proven technologies, we deliver a solution that meets your requirements:

Channel heat exchanger with dry weather channel

  • Suitable for all channel shapes, quick installation
  • Optimum use of heat, as it is completely overflowed even in dry weather
  • Supply and return lines are routed below the heat exchanger to ensure easy maintenance of the channel by the operator

In the tube integrated heat exchangers

  • For new construction of a canal
  • Fast and uncomplicated installation

External heat exchangers

  • For large projects with 500 kW power and more
  • Wastewater is pumped out of the sewer via a shaft and pre-cleaned via a mechanical filter
  • By means of externally mounted heat exchanger bundles and heat pumps, extremely high efficiencies (COP 7 to 8) can be achieved

Building services of the future - with hot water treatment

Day after day, a considerable amount of wastewater accumulates in buildings. With innovative, self-cleaning heat exchangers, it is possible to recover up to two-thirds of the heat from the wastewater and use it efficiently for hot water preparation. The result: less energy consumption, less costs, less CO2 emissions.

Rabmer supplies innovative heat exchanger systems for this:

Heat generator – static system

  • The wastewater is collected in the mantle of the tower and heats the fresh water in the inner tank.
  • The heated water is removed from the upper part of the inner container and fed as preheated fresh water to the existing water heating system.

Plate heat exchanger – continuous system

  • The pre-treated wastewater flows through the countercurrent heat exchanger and heats the incoming fresh water.
  • A cleaning scraper removes the dirt on the heat exchanger surface daily, whereby an optimal heat transfer is guaranteed.

Basic requirements

  • Waste water quantity: at least 2 m3 per day
  • Residential buildings: gray water pipeline separate from fecal waste water; Central hot water available
  • Spatial proximity of the sewer to central hot water

Area of applications

  • Baths, sports facilities
  • Hotel industry, wellness parks
  • Commercial kitchens, hospitals
  • Food processing industry
  • Laundries
  • Residential complexes
  • Retirement homes
  • And much more …


Our services for you:

  • We are looking for the best technology for your project.
  • We carry out a feasibility study for you and calculate the profitability.
  • We take over the implementation including delivery and installation with our partners.
  • If necessary, we also take care of the maintenance and operation of the system.

We are happy to help

Contact us:

Rainer Wiedemann
Head of energy from wastewater
+43 7230 7213 742

Inquire now