DWHR / Green Building & Sustainable Home Renovation Information & Advice

A  copper drain water heat recovery unit in a residential plumbing stack.
Hot water

Drain Water Heat Recovery: Efficient Energy Recycling

...dwhr for slab on grade foundations In brief How drain water heat recovery works How the falling film effect transfers heat The most common DWHR systems consist of a copper potable water tube wrapped tightly around a central copper drain pipe. As warm shower water flows down the drain, it does not fill the pipe; inste...