You don't need to solar preheat your incoming water. What I mean is simply setting the extra tank up in line with the cold to the water heater will let the water sitting in the tank between uses rise above the temp it comes from the well at.
Better if its directly heated by the sun but every degree you raise it before it gets to the heater is one degree you don't need to put into it energy wise.
Just a thought. I call this an "ambient air temperature preheater"
Tom
"Education consists mainly of what we have unlearned."--Mark Twain
Are you sure that's a benefit? Aren't you bringing a whole bunch of cold water into the house to just suck heat from the air? That air that was heated somehow by using energy. Heat the air in the house more, to "pre-heat" the water. I don't get it. Sounds like a zero-sum game.
What would be really neat would be a system that lets you transfer heat from waste water (eg from the shower, or better yet, dishwasher) in that pre-heater tank. Can't picture big economic benefit in a house, but maybe this could be (or already has been) done in a commercial building.Steven Fahey[ Parent ]
Just ideas.
If I am now required to explain every minute detail of the down sides to advice I will just stop offering it. I will leave that to the academics sitting in their offices.
I did this for years on the north side of my house and it worked great with no direct sun on the tank. When I had 2 in series it would get the second tank pretty close to the same temp as the air. I probably lost some gain to radiation to the night sky, too, but it was a net gain. I suppose I should note, in order to avoid you explaining the obvious, I only did this while outdoor temperatures were above 55 or 60 F. We have no basement. Info is in my Diary someplace since I actually shared it here long ago.
And, yes, waste heat recovery sounds good but likely not trivial for the non plumbing oriented.
"Education consists mainly of what we have unlearned."--Mark Twain[ Parent ]
After posting I remembered that there's a building in Calgary that has a heat-exchange system on waste water. Probably city-owned. Just wanted to add the idea to the thread because it's always sounded interesting to me. Steven Fahey[ Parent ]
Depends on where you live? We don't heat the house about 7 months a year. 3 months welcome any cooling. If I could get the water from 55F to 72F, that is a gain.
My cheapie water heater is far less efficient than my furnace. Much of the water temp increase would be caused by heat from the efficient furnace, instead of the cheap water heater. That would mean a gain too... I think.
Here, the electric co gave a reduction in rates if an 80 gal tempering tank was installed before an electric water heater. No idea if they still do. =
That waste water thing is cool. Someone did a study of a working unit in a USA duplex, and I figured DIY payback was like a couple months before copper went up. I would have one if our shower was over a basement. :-/
I often thought SOMETHING before the recovery part would increase the temp. Maybe 50' of 3/4" CU. Maybe 25' of 3/4 CU with 6" pieces of scrap #12 soldered to the sides as a heat sink (anti-heat sink?).
And maybe if that verticle do-hickey was insulated it would work better.
I see there are a buch of new replies since I started, but I'm leaving this as-is. G-[ Parent ]
mixerman[ Parent ]
A grey-water sump as you have shown will accumulate 'bath hair' and worse and breed exciting biofilms and worse IMHO!
Rgds
Damon [ Parent ]
Perhaps a flapper valve and toilet hardware would work?
For grey water think big diameters and slow.[ Parent ]
I think what is meant is a virtical drain pipe is coiled on its outside not in any direct contact with the heated gray water.
In my pictue you will see that the coils are in contact with the gray water, Im sure this would allow for some kind of build up! (soap scum, hair, cooties)the core of the tank would be self-contained though! Dont really know if the build up would really effect its effenecy or create some kind of hassard.
The plumbing would remain the same size in use in the system 1 1/2" traps should work fine , the existing drain traps have never cloged in 20 years. For a controled drain maybe a ele t-stat! I think some cas have them today.[ Parent ]
Originally my thoughts were just set it out in the Sun, drain lines an dont use it in Winter.[ Parent ]
I added a set of frostless faucets to the outside one Ted off before and one Ted off after a ball valve in my cold in to the heater. attach tank to those with top to the after faucet and the first faucet to the bottom [or dip tube] of the tank. That way, come freezing weather you just turn off the faucets, remove the lines, open the ball valve and you are back to "normal". When using the preheater you close the ball valve to force water to go through the preheater. My water heater is within a few inches of the north wall of the house and I bought good quality washing machine hose to go from the faucets to the tank.
You could easily do it both in and outside with some thought.
Good luck with it.
