These areseveral smallhot water tankswith heat
exchangerlocated ineach unit always withone or
morelayers ofcollectorson the roof.It is adistribution ofhot wateror liquidcoolantwhich in turnheats the waterin the water storage
tank.This system is usedmore frequently in theapartment complex,
itcan be coupled toaheat recoverysystemon a group ofcold production.Theheated wateris only
used toheat waterstorage tank.This system providesaseparatemeteringof water consumptionin homes.