Do this one thing

Write down the water temperature, the flow and where the heat would go.

Record only these

  1. Water temperature and flow, with units
  2. The lowest temperature this stream is allowed to leave at
  3. Whether the heat would go to an in-plant loop or a heat network
  4. Whether that demand exists in the same season and the same hours

If temperature, flow or the destination is still blank, measure them first. Do not treat the whole stream as useful heat.

When the stream and the destination are named, open the wastewater and heat-network pathway

Name the liquid stream and where the heat would go. An in-plant loop and a heat network are different boundaries, and the whole stream is not useful heat.

Name the liquid and where the heat goes

This page is for wastewater, process liquid and sewage. An in-plant hot-water loop and a district or campus heat network are different boundaries. The required temperature, the contract and who operates the network are not the same decision as heating a tank inside the plant.

Measure these together

Flow, fouling, the minimum outlet temperature, and whether demand exists at the same time all change how much heat can be taken. Cooling a stream below its allowed outlet can break a process limit or a discharge limit. A source that exists only in summer and a network that needs heat only in winter do not automatically match.

This page does not design a heat network or size a heat exchanger. Fouling that has not been observed stays blank.

Other sources stay outside this page

Flue gas, seawater and ambient air can also feed a heat pump. They fall outside this wastewater and process-liquid checklist. Seawater is a liquid source and needs its own checks for intake and discharge, corrosion and ecological constraints. When the source is one of those, continue from the opportunity atlas and name the source before screening.

Choose the next step

If the destination is still unclear, mark the stream and the user it might serve on one sketch, including the seasons each one runs. When flow, temperatures and overlap are known, open the wastewater and heat-network pathway, then the focused screen. Screening does not design the network.

Sources and limits

This is an editorial learning guide, not a plant audit or a measured savings result. Site inputs remain unknown until supplied and checked. Detailed design, procurement, hygienic and pressure-equipment decisions require qualified review. Read our editorial principles.