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Leading in greywater recycling

For over 25 years, INTEWA has been a technology driver in the field of rainwater management and utilization. For over 12 years, INTEWA is having experience with greywater recycling. Several hundred INTEWA greywater recycling systems are now running in over 20 countries worldwide. With our NSF/ANSI 350 type commercial certified systems are leaders in the market. Every day, numerous new customers choose INTEWA technology. You too can become a greywater recycler. It is worthwhile. We are looking forward to your project.

Greywater recycling for Commercial

Up to 65% of the water demand of many buildings is used for showering, bathing, washing hands and for the washing machine. The resulting wastewater is the so-called greywater. With AQUALOOP technology, this water is treated in a membrane bioreactor and then stored in a clear water tank. The heat contained in the water can also be recycled via a heat exchanger using a heat pump. The treated water is of excellent quality and is reused for toilet flushing, irrigation and washing machine use by means of a pressure boosting system and further UV disinfection.

Especially for sports facilities, schools, hotels and apartment buildings with significant amounts of shower and bath water and a matching service water demand for toilet flushing, washing machines or irrigation are suitable for a greywater recycling plant. However, many office buildings can also use water from hand washing sinks. Unlike rainwater harvesting systems, greywater systems are independent of roof surfaces and precipitation conditions.

A particular advantage is also that the greywater yield and demand have a good degree of coverage in terms of time. During vacation periods, for example, when less water is needed, less water is produced.

Only a correspondingly small amount of water is also treated. Since a separate greywater and process water piping system is required for greywater recycling plants, new buildings or renovation projects are usually suitable. Here, the separate pipelines cause justifiable additional costs. To allow good accessibility and maintenance of the plant, the installation of the plant should be inside the building.

Particular advantage of greywater recycling


Saving of drinking- and wastewater charges at the same time

In view of constantly rising costs in conventional drinking water supply and wastewater disposal, saving water is becoming increasingly important. But where saving drinking water is no longer enough, new sources of water must be found. What could be more obvious than reusing your own water? Greywater recycling can be the ideal solution. This double use saves both drinking water and wastewater fees. In many countries, drinking water and wastewater costs are already over 6.00 $ /m³ together.  


Heat recycling and thus saving energy costs

In modern, well-insulated buildings, more energy leaves the building with the warm wastewater than is needed for heating. Most of this energy is contained in the greywater. If a greywater recycling system is installed in a building anyway, it makes sense to extract this energy from the treated greywater shortly after the point of origin via a heat exchanger using a heat pump and to feed it back into the hot water system.

More information about heat recycling with treated greywater


Greywater recycling is economically worthwhile

INTEWA greywater recycling technology has been continuously developed and optimized in recent years. Depending on the water price, the size of the system and whether the heat is also recycled, our systems can soon have very short payback periods, which make the use of a greywater recycling system one of the most economical technologies in the construction sector like the following example shows.

Read more why greywater recycling is economical

Achieve sustainable building standards and increase building value

With a greywater recycling system you make a significant contribution to achieving the sustainability goals of the United Nations. Greywater recycling saves valuable water.

  • Increase in building value
  • Higher classification in building certification, DGNB, LEED, BREEAM and many more
  • Financing advantages (interest) due to EU taxonomy sustainability classification
  • sustainable investment, ESG (environmental, social, governance)

Read more about achieving sustainable building standards and increasing the building value

INTEWA's solution for smart greywater harvesting

Pre-assembled greywater recycling systems

Our complete greywater systems with AQUALOOP ultrafiltration membranes as well as biological and chemical cleaning offer the best technologies for the production of reusable process water in the smallest of spaces. We offer our systems in nine different sizes in order to be able to present a suitable solution for every commonly required treatment volume. Find out more about the technology and the structure of our complete systems.

Read more about pre-assembled greywater recycling systems

The greywater recycling system of the future can be controlled from anywhere. Reading consumption and statistics as well as optimising the system parameters with recommendations for maintenance are just a few tangible advantages that this technology brings. For large buildings, integration into the local building management system is possible via the already integrated interfaces. This significantly optimises the operating and maintenance costs and contributes to further optimising the economic efficiency of the systems.

Expert control

  • I-CONNECT controls
    • Condition monitoring
    • Process control
  • I-CONNECT web application / app
    • Remote monitoring


References greywater recycling

Our greywater systems have already been in use for several years in various countries around the world.

Project service from A to Z

We will guide you through all phases of planning your greywater recycling system, from design to execution of your project.

  1. Concept creation and price calculation for the preliminary planning
  2. Support in implementation planning
  3. Creation of CAD system drawings
  4. Compilation of tender texts
  5. Support for executing companies during execution/installation
  6. Commissioning Service
  7. System monitoring This is where our I-CONNECT comes into play

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