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Use Grey water produced by the public housing complex as a heating/cooling source replicating a geothermal system at a lower cost.



What is Grey water? It is waste water draining from bathroom sinks, bathtubs, commercial/residential/office kitchen sinks, showers and floor drains that does not contain human or animal waste products.

Grey water reused in today's modern plumbing infrastructure is exclusively for flushing toilets,  which in turn saves energy and water utility costs. This use of grey water (non-potable water) is stored and then recirculated to assist with the moving of effluence from bathrooms to municipal sewer systems.

In this proposal we expand the storage of grey water and use it as a baseline temperature for building HVAC systems similar to the geothermal heat concept. So instead of getting a baseline temperature from the Earth in the case of a geothermal heating system, the greywater system's heating baseline corresponds to the ambient interior temperature of the building.  In both systems there is considerable energy cost savings for heating and cooling the building. But unlike the geothermal system which requires considerable upstart costs for drilling into the Earth and burying PVC pipes for liquid storage the Greywater system works seamlessly within the floor by floor infrastructure for utilities, as it is merely an expansion of existing interior, plumbing systems.

Lastly, using grey water through a capture and re-circulation system reduces water use by over 30%/

Is this proposal for a practice or a project?


What actions do you propose?

The first step is the test case implementation of the system. The targeted demographic for the project  is low-income, or economically disadvantaged high-rise, public housing.

Who will take these actions?

This project would be primarily a non-profit/public partnership, and exclusively serve the public,and not the private sector.

Where will these actions be taken?

As the project gains support focus will follow. The test project will take place ( at the Regent Park housing complex) in a northern climate since that region of the globe experiences four seasons or heating and cooling, HVAC cycles.

In addition, specify the country or countries where these actions will be taken.


Country 2

No country selected

Country 3

No country selected

Country 4

No country selected

Country 5

No country selected


What impact will these actions have on greenhouse gas emissions and/or adapting to climate change?

Once implemented, the energy use required for the pilot, grey water system for heating and cooling of Regent Park will go down therefore the carbon footprint will shrink as well.

What are other key benefits?

  1. More people will need to be trained and hired for the types of positions needed to install these greywater heat pump systems.
  2. Future electric grid load demands will go down during peak heating and cooling times as compared to previous years with non-greywater heating/cooling systems.
  3. If these greywater heat pump systems are installed city wide a municipality may reach its' goals for carbon footprint reduction sooner than predicted since the concept proposed in this project was not considered.


What are the proposal’s projected costs?

There will be down time as with any infrastructure reconstruction project, but not any different than painting and replacing flooring in a remodeled office space.


It is anticipated that two years will be needed to have the first pilot project online. The first year for coordinating with the non-profit and governmental agencies, funding, and a public awareness campaign. The second year will be the installation of the Greywater Heat Pump system in the selected low-income, high-rise housing and the daily monitoring of said system for energy savings, CO2 reduction, usage, safety and maintenance.

About the author(s)

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