Recirculating Shower

[ballvalve]

How about that jetted tub with a heater incorporated, some do, and tee off of the lines or kill a few jets and run them up the wall to a spray head?

Now you shower while standing in a foot of water, and can be sprayed or soaked all in one shot.

Cheap and elegant solution, with all the seperation from incoming water incorporated.

As to heat recovery, I always think of a 1,000 roll of pex tossed in the septic tank to feed the water heater. But I suspect some "small" issues of contamination may prop up.

Take a look at jacketed wine tanks. Small ones are made that are meant for glycol to cool the innards. They would work safely in reverse, with the shower and tub the heat source. Insulate heavily.

I built a long water heater 4" pvc exhaust with a 2" inlet combustion air centered inside it for a Polaris. Cold exhaust!
Polaris used to ship the units with a short version of this included. For some odd reason, the added restriction stopped all combustion code failures.

[garynekula]

Is there some type of valve that can be connected to the two inch drain line that can be operated electrically, or can have an extended stem (extended by about three or four feet) that can block the drain to allow recirculation?

[BarryM]

Does anyone remember the small saunas that used to be popular? Why not build a shower size box like the old saunas, completely independent of the home plumbing. There could be a tank in the bottom, with a filtration system, heater and pump that recirculates the water that runs into it. Water can be filtered to be as clean as you want it, even purer than what comes out of the faucet. The problems mentioned above wouldn't be an issue, if my thinking is correct. I'm building a truck camper, and am contemplating installing such a setup. Seems rather simple.