Warm effluent is a useful source
Laundry wastewater can retain significant heat. Screening, fouling and corrosion must be addressed, but the source often coincides with new hot-water demand.
Drying needs air-system analysis
A closed or semi-closed heat-pump dryer can recover latent and sensible heat. Product quality, humidity control, lint and required drying rate determine whether this is suitable.
Water and heat measures interact
Reducing water use changes both heat demand and effluent flow. The heat-pump design should follow the revised water balance, not the historical one.
Measure the revised water balance first
Warm wastewater can coincide closely with incoming wash-water demand, but water-efficiency measures change both flows. Establish the future rinse volumes, discharge temperatures and batch schedule before sizing recovery equipment from historical consumption.
Lint, detergent, pH and suspended solids affect fouling and materials. Screening, a cleanable exchanger or an intermediate loop may be necessary. Their temperature approaches and pumping power belong in the seasonal performance calculation.
Analyse drying as a separate cycle
A closed or semi-closed heat-pump dryer can recover sensible and latent heat, but air temperature alone does not define performance. Humidity control, recirculation rate, product moisture, drying time and lint management determine capacity and quality.
Compare water heating and drying as separate projects before combining them. They may have different operating hours, temperature lifts and resilience needs. Metering should distinguish useful heat from electricity used by fans, pumps and the compressor.
Sources
General technical explanation. No specific external source claims are made on this page.