3 ms·
I think you'd need a reservoir to hold the hot water before it drained for a heat pump to be effective when the inflow occurs before the outflow (as with a dish
by pingswept 17y ago
I think you'd need a reservoir to hold the hot water before it drained for a heat pump to be effective when the inflow occurs before the outflow (as with a dishwasher). The reason that the coil systems are relatively efficient is that they are pulling cold water past hot. Using hot water to heat the warm water in a tank will be much less efficient.
If you're interested, see http://en.wikipedia.org/wiki/Thermal_efficiency http://en.wikipedia.org/wiki/Thermal_efficiency
- stcredzero 17y agoI suspect that the reason why some drain heat exchangers incorporate a significant amount of brass, is to act as a heat reservoir. You'd often be better off putting that money towards a solar hot water system. Thermomax evacuated heat tubes work almost anywhere, and aren't subject to the same service life limitations as photovoltaics and batteries.