Reclaim waste water heat.
 

City water coming into my home during January measured about 34.7 F - 2 C. To pre-heat the water for the hot water heater, I decided to use the water going down the shower drain.

Finished the hot water heater plumbing tonight. Have it pressured up. No major leaks so far. I arranged shut offs so I can cut out the Pre-warmer. Tomorrow I'll plumb in the drain water from the shower. When I have time I'll add the drain water from the dish washer.

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This is the south facing wall of my home. During the summer I hope to add a Solar water heater to the side of the house And add four barrels to pre heat the water.

WOW! You are into soooooo many projects. Lucky!

Are you going to insulate the barrel? And do you think that debris build up on the coils will be a problem?

You know, this may be the first project to reclaim heat from waste water that I've ever seen. I've read many times that waste water has heat that can be reused, but I've never seen it happen. I wish you luck with the project and please keep us updated.

I think this is as close to a build and forget as you can get. No moving parts and mostly plastic. Could put some septic Microbe starter in it, let them tend to the cleaning. Be easy to add a small pump to use the water for irrigation

I'll box it in with Styrofoam with the other four barrels to keep the heat in, later.

Right now, I'm trying to figure out how to get the best heat exchange. The coil well pick up some heat but the length only holds about a gallon. If the waste water in the barrel was in motion the coil would pick up more heat. Maybe a air stone.

Next thought would be to put a small metal tank about five gallon, in the barrel in front of the coil to keep the cold water in the warm wast water longer. Like a small bulk storage warming up.

Done. So far no leaks. I think, it well take about five more showers to fill the barrel. Then I will find out if the lid or connections will leak. If I remember right, the pressure in the barrel should be close around 14.7 PSI.

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This is the done pix.

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I put in a length of pipe so that the shower water enters at the bottom of the barrel. To help stir the water. The lid is about an 1/8", maybe 1/4 Centimeter or less thick. The only thing, holding things together is, two slip fittings and pipe glue.

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just a before plumbing pix.

Spent less than a hundred on this. I know it will pay for its self. As you see it the heat is bleeding off into the basement. Not sewer.

A box will have very small surface area compared to its volume, so heat transfer will be slow. Maybe a few small boxes (or cylinders, made out of large diameter pipes), or another coil, plumbed parallel to the first?

:thumbup: I think your very right on this. Found this tonight. Close to the middle of the page.
$1000 solar water heating system -- storage tank
Thanks.
Kevin

Kbhale, why don't you use the grey water for flushing, as Ben did? In your system the greywater is already sitting in a barrel in the basement, just waiting to be pumped to the toilet, so why not?

I just installed Glacier Bay Elongated Dual Flush 1.1/1.6 GPF
Glacier Bay Elongated Dual Flush High Efficiency 1.1/1.6 GPF All-in-One Toilet - N2316 at The Home Depot

Without heavy filtration, I be afraid the Grey water would cause the filler parts needing to be replaced to often. Think it better to use rain water for the toilet and the Grey water for roses.

I have a lot of projects in motion now. Main focus is heat and insulation of the home. I have started rain barrels and later on when I build a storage tank in the basement for hot water. I think, I'll build a third one ( 500 gallon about 1*892.7 liters) for rain water and use it for toilet , cloths wash and garden.

Note on toilet: I like it.

Hi,
Nice simple setup.

I'd really like to hear how it works out.
Maybe you can measure the temperature of the incoming and outgoing fresh water and get an idea how much of a preheat you are getting?

I've heard that grey water gets pretty smelly after a day of sitting around, but I guess that this might not matter since its all enclosed.

There are a couple articles on grey water heat capture here:
New and experimental solar projects and concepts* for do it yourselfers

The first one is one that Nick Pine and I worked on, but eventually pooped out on. The "Canada Study ..." is a good one.

It seems like the whole idea of recovering heat from grey water does not get enough attention, and that there ought to be a simple way to do it -- maybe you have found it.


Gary

Update?
 

How's the system doing? Any problems? Did you put any microbes in?

For the last month I think about this project each time I take a shower, and I wonder: With a set-up like this, is it OK to pee while showering? Peeing in the shower is a way to save water (Brazilians Urged to Pee in the Shower to Conserve Water), but will it be too diluted to cause any problems down in the barrel? Will the water be OK for flushing later?