Project 5: Vlario – Heat recovery from the sewer system

Planning Realisation Monitoring Evaluation
Vlario – Heat recovery from the sewer system

One of the possibilities to reduce the need of conventional energy for households is sewage heat recovery. At this moment, recovering heat as a source of energy doesn’t really exist in this field. Investigating heat recovery from municipal sewers opens the scope of possibilities for this kind of sustainable energy. VLARIO will tackle a project involving a heat exchanger placed in a local sewer, directly supplying thermal energy to 100 nearby situated houses.

The following questions will be taken into account:

  • What is the viability of the municipal sewer system – which is the minimum diameter and flow velocity?
  • To what limits is the system of heat recovery using heat exchangers possible?
  • What should be taken into account when constructing this system?
  • What are the parameters / constraints that need to be taken into account when implementing the project?

Another issue that will be investigated by VLARIO is the legal part. The main question to be answered here is: are there any regulations, orders or laws dealing with the recovery of heat out of wastewater in sewages? The focus will be on the installation of equipment, and use and maintenance of the equipment.


  • Insight in the potential applications for thermal energy from local sewers, including answers on questions like: which is the most ideal application? What are the constraints?
  • Insight in the legal aspects to be taken into account when recovering heat from sewers.


  • The feasibility study has been done and the implementation of the project is planned in the spring of 2014
  • The juridical screening is also be done in the spring of 2014