Drain Water Heat Recovery Diy

Shower with dwhr installed our mission is to develop and market a small and affordable heat exchanger for shower cabinets and promote the use of drain water heat recovery dwhr systems in homes.

Drain water heat recovery diy. With a drain water heat recovery system the cold water heading to the water heater first picks up some of that waste heat from the drain pipe. A lot of this energy can be recovered. As warm water flows down the waste drain incoming cold water flows through a spiral copper tube wrapped tightly around the copper section of the waste drain. Thus it enters the water heater pre warmed and will take less heat energy and money to get it up to temperature.

The energy department estimates that energy losses in hot water amount to 80 to 90 a good argument for installing a drain water heat recovery dhr system. By preheating cold water drain water heat recovery systems help increase water heating capacity. In a gravity film heat exchanger gfx drain water flows through a copper pipe that is wrapped in smaller diameter copper tubing. The building inspector will not certify my job because the powerpipe does not comply to the building and plumbing.

This increased capacity really helps if you have an undersized water heater. The devices being promoted are supposed to recover heat that would normally go down the drain and use that energy to. Wrap the soft copper around the pvc and slide it into the 4 drain pipe. Take 1 or 2 pvc whichever will support the fit.

When doing this encourage the soft copper to be a snug fitting spiral between the pvc and the 4 drain pipe. Since drain water hugs the wall of the pipe when draining lets encourge the path. This preheats the incoming cold water that goes to the water heater or a fixture such as a shower. The water used for showering still contains a lot of energy when it flows down the drain.

The efficiency of your water heating system goes up and your water heating bill goes down.