Down Drain Heat Recovery

The concept of down drain heat recovery is a really good one. You take the (mostly hot or) warm drain water from a shower as an example, and pass is through copper pipe that is wrapped around the fresh water intake pipe leading to the hot water tank. The idea being that the energy from the “shower water” will preheat the fresh water going to the hot water tank, such that we won’t have to energize the fresh water as much to heat it to full temperature.

In theory this sounds great, in practice I think you would need to be having really long showers, or have a great deal of people in the house having showers one after the other to truly make this a viable technology.

In other applications such as condo projects and multifamily projects that are using a shared utility like this one, it may have greater significance.