HEAT RECOVERY

RECOVERING HEAT, INCREASING EFFICIENCY AND REDUCING EMISSIONS

The energy used for heating water for domestic purposes such as washing dishes and showering is wasted down the drain. This waste heat can be repurposed for use in space and water heating in buildings, increasing efficiency and reducing emissions

Using sewer heat to warm radiators, sinks and showers

During sewage heat recovery, waste heat from flowing sewage is captured by heat pumps. In some cases, other heat sources such as natural gas can be used to supplement the heat supplied, especially on the coldest days of the year.

Heat exchangers transfer this energy to water which is distributed to buildings in the neighbourhood. Each building that is part of the distribution network would have an energy transfer station that transfers thermal energy from water to the building’s mechanical system which distributes heat and hot water to the building occupants. Cold water, after heat has been removed, is circulated back to the system.

Photo Credit: Alfred Hermida

BENEFITS

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REDUCES UPGRADES

Heat recovery systems reduce the size and frequency of heating upgrades and new machinery.

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INCREASES EFFICIENCY

By capturing heat that is otherwise wasted, heat recovery systems increase resource efficiency.

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OTHER RESOURCES AVAILABLE

Besides thermal energy, other resources are available for reuse from waste water, including organic matter, phosphorus, nitrogen, and heavy metals.

Photo Credit: Alfred Hermida

Considerations

COSTLY TO IMPLEMENT

A heat recovery system requires a lot of equipment and installation, making the up-front cost high.

NEEDS OTHER ENERGY SOURCES

Heat recovery often needs to be supplemented by other energy sources. Capturing waste heat lowers the required energy needed but an energy source is still required.