Device for light-grey-water residential flushing?

[avramd]

Hey everyone,

Hard to google for, no results so far other than "bucket" and "expensive"...

Long story short, my house has a "tankless" hot water system, and it takes a really long time to get hot water to the shower or sink. Newport is technically on an island, so besides being straight-up wasteful, our water is very expensive. 4 people use about 4500 gallons a month here, and that costs around $200.

We currently conserve water by capturing the water that we run-off waiting for it to get hot in a bucket, and then flush the toilet by dumping it in the bowl. The solution is far from ideal. In particular, during a tank-flush, you end up with a bowl full of clean water. With the bucket-flush, usually we end up with a close-to-empty bowl of still-kinda-dirty water. Smaller issues are that it's easy to spill, and gee it sure is a luxury to just press the lever instead of having a project to deal with before you're done with your business.

I'm wondering if there are any simple/inexpensive systems out there that let you dump that water into an auxiliary reservoir connected to a toilet's tank at prior point, and then that will (primarily) fill the tank rather than fresh water after a flush? I'm visualizing something using large-bore siphons that race to fill the tank with grey water before more than a fraction of it is filled from the clean water supply - thus there's no risk of over-filling, and it doesn't need power or a motor. But I'm open to alternatives.

[Ken Heaton (Salazar)]

Have you considered installing a hot water recirculation system?

https://www.nachi.org/hot-water-recircu ... 20fixtures.

[LarryHoward]

I happened to see this earlier today. It’s a start.

Edit. Attachment didn’t make it.

8CA3739F-035A-4341-B48B-E368F9DFFB42.jpeg

One thing to keep in mind. Once the water exits the faucet and enters the “environment”, it’s contaminated great water and has to be separated from the water supply by a siphon break to prevent it from mixing with the water supply. Recirc systems stay in the supply lines. Grey water reuse is by definition contaminated and where it enters the toilet tank, has to have no path back into the supply.

[Steele]

We have a recirculation pump using the cold water pipe as a return line, It worked well. I purchased this one, https://www.amazon.com/LHB08100093-Auto ... 51&sr=8-55. It is expensive but worked well since I have minimal plumbing skills and it is all an all in one unit that fit under the kitchen sink and plugged in to an outlet that was already there for the dishwasher. It makes the cold water hot for a bit, but that is less of an inconvenient than waiting for the hot to warm up. It has a timer but I bought one of these, https://www.amazon.com/Century-Wireless ... 868&sr=8-9. We keep the remote by the sink, hit the button when we need hot water, and in a few mins we are ready to go.

A few months ago we got rid of the big tank and switched to an on demand propane hot water. In theory it should work the same, but I was unsure about the implications of pumping water backward into the instant heater boiler. If anyone has any insight I am all ears.

[avramd]

Ok, ok, I'm super-intrigued, but not 100% following.

I was aware of the dedicated loop idea, but that would require running new pipe all over the place, and it's a somewhat large 3-story house, so this seems impractically expensive. One idea that occurred to me for this though was that perhaps there is a "pipe within a pipe" product that could be fed up from the basement in the same hole as existing pipe, turning one path into to, the second one being the return.

I don't understand how the "integrated loop" thing works. I hear the words "the cold water pipes serve as the return," but I can't visualize it. I thought there were two different networks of pipes in a house, one hot, one cold, and both were "trees" - they only ever branch except when they meet at a faucet. And then at the faucet, the water is still separate until the faucet is turned on and mixes them. So I don't see how a pump in one location could push the hot path and have it return through the cold.

If the new device itself connects the hot to the cold, then I can see how that would return the hot supply through the cold, and create a loop - but it seems that would only benefit the faucet where the device itself is installed? And to get this benefit at a shower, you'd have to open the wall to install such a device at each one? Which is clearly not how it works, I'm just expressing my confusion.

[Steele]

Recirculation devices have a valve bridging the hot and cold lines installed just shy of fixture furthest from the hot water tank. When the electric pump is turned on the valve opens and water is pumped the proper direction in the hot water limb through the valve and then the "wrong" way back on the cold water limb to the tank. When hot water makes it to the valve a temperature sensative plunger closes and the pump stops. This keeps the pump from running continuously, and reduces heating of the cold water side.



Because most houses have a main trunk for the hot water line most of it will be filled with hot water by the pump. Fixtures on spurs off the main line will have cold water in the short segemet connecting them to the main trunk, but in our experience still get hot much faster. I suspect if you have a complex system with mutliple hot water lines it would not work as well, or need multiple pumps.

[Ken Heaton (Salazar)]

Ok, ok, I'm super-intrigued, but not 100% following.

I was aware of the dedicated loop idea, but that would require running new pipe all over the place, and it's a somewhat large 3-story house, so this seems impractically expensive. One idea that occurred to me for this though was that perhaps there is a "pipe within a pipe" product that could be fed up from the basement in the same hole as existing pipe, turning one path into to, the second one being the return.

I don't understand how the "integrated loop" thing works. I hear the words "the cold water pipes serve as the return," but I can't visualize it. I thought there were two different networks of pipes in a house, one hot, one cold, and both were "trees" - they only ever branch except when they meet at a faucet. And then at the faucet, the water is still separate until the faucet is turned on and mixes them. So I don't see how a pump in one location could push the hot path and have it return through the cold.

If the new device itself connects the hot to the cold, then I can see how that would return the hot supply through the cold, and create a loop - but it seems that would only benefit the faucet where the device itself is installed? And to get this benefit at a shower, you'd have to open the wall to install such a device at each one? Which is clearly not how it works, I'm just expressing my confusion.

Imagine a small pump with a check valve that is connected between the hot and cold water lines (say in the cabinet under the sink) at the set of faucets furthest from the water heater. So you want hot water at that sink. You turn the pump on and it draws water from the hot water line and pushes that water into the cold water line (now going backwards down the cold water line). This backwards flow can't go anywhere (unless there is a cold water tap open elsewhere) except into the cold water inlet of the water heater (and this water is at most, at room temperature), where the pressure is lower because you are pulling hot water out of the water heater with this pump. As soon as the hot water get to the pump it shuts off with a internal thermostat. Now you have hot water at the faucet furthest from the water heater, and you haven't wasted any water, as you just recirculated it all.

Now all the water in the water line from the water heater to the furthest faucet is hot. Any faucet closer to the water heater now just has to flow water from where it branches off the main hot water line and the water is hot there too.

Make sense? It is important to insulate all the hot water lines if you want to make this more efficient. It could be a short duration timer switch you hit to turn it on, or some other arrangement like a time of day timer. You could have more than one switch if you have a faucets in different rooms that are far from the water heater.

[avramd]

Guys, I really really appreciate this. This is starting to come together in my head and make sense.

The "concern" I had, which seems pretty silly now, was that my 3rd floor bathroom sink was part of a spur that comes from the 2nd floor kitchen sink, which is right below it - and that the 2nd and 3rd floor showers, which are one-above-the-other, were a different spur, and that was the spur I cared about, but had no access to (except for cutting into pipes all the way down in the basement).

In thinking it through more, that was silly. The kitchen sink is back-to-back w/ the 2nd floor shower, so that is definitely one spur. And the 3rd floor shower is right above the 2nd floor one, so that is definitely an extension of that same spur. And then the rest of the 3rd floor bathroom is surely off of that same spur, just happening under the floor where I can't see it. It would be insane for there to be two stories worth of extra copper feeding the 3rd floor sink & tub separately from that same bathroom's shower.

So, it really sounds like if I put one of these on my 3rd floor sink, that will cover basically everything, except for presumably 3-5 feet of pipe depending on where the branch point is between the sink and the shower. That's nothing

So, now that this seems like a real thing I'm going to do, here's a new concern/question. The 3rd floor bathroom sink is fed by pretty small diameter pipe. The shutoff valves for it appear to reduce the diameter significantly, and they are sweated on - so I think I'd need a real plumber to replace those. Do you think it'd be a problem running this whole system through such a small diameter choke-point? Would that substantially slow down how long it takes to actually heat the loop? See photos.

The alternative is I could put it on the tub. These are 1" diameter pipes, and they are exposed for aesthetic purposes. But the only entry point is the tub faucet itself, otherwise I'd need to cut them down below to insert this device, and again, that sounds like "real plumber" land. See photos.

[Steele]

It is hard to know until you try. The kits use flexable connectors so you could hook it up yourself and give it a try. They run around $200. If it is too slow then swaping out the turn off valves is the next step, but you would use the same pump kit. Because you do not have a vanity the pump is best fitted near the water heater with the valve at the distant sink so take a look to find a spot to add the pump and a nearby outlet to plug in.

A note of caution, old shut off valves like you picture have a high failure rate. I have had two start to leak badly in the past year. They were fine until I used them to shut off the water to fixture after which the valve leaked around the shut off knob and we had to turn off water to the house to replace them. I would choose a weekday morning for your project, finding a plumber on a Satrurday afternoon is challenge.

[avramd]

Hey All,

So, this project is advancing - slowly, and yielding a couple of basic plumbing related questions.

TL/DR:

• Is "sweating" fittings onto copper pipe something I can realistically expect to learn to do well myself in few enough iterations to replace those shutoff valves myself before wishing I had just hired a plumber?
  
  • I am at about a C- in terms of my ability to solder electircal wire. I've never soldered plumbing. FWIW, with wire, I usually end up with something functional but ugly, and some amount of collateral damage. My burn victim count is non-zero.
• Can you "re-sweat" a new fitting onto the same copper pipe end that already had one? Or do you need to trim it and start clean?
• PEX crimping - how permanent is it? Are the joints recoverable and re-usable? If so, can the PEX be re-crimped as-is, or does it need to have 1/2" or so trimmed off so that you're crimping virgin plastic?

Long version:

I have three separate plumbing projects all of which seem like I should be able to accomplish them myself. Contractors around here are slippery, and I don't have a plumber that I can trust to charge me the real effort a job takes. I was quoted $1000 to install a garbage disposal.

I know going into this that I may have to replace the two above-discussed shutoff valves. I have another sink shutoff valve that seems to be stuck partly closed already, giving me low hot water pressure at that sink (cold pressure is fine). In both cases, there isn't enough copper exposed to cut the sweated end off to get bare copper.

Lastly, but most importantly, I recently discovered that when I had both oil boilers replaced with high efficiency gas ones (I own & live in a two-family) the frigging a$$hole contractor used my unit's water supply to feed both boilers. So for the last 7 years, I have been paying for my tenant's hot water. She's paying to heat it, but I'm paying for the water. Newport is an island, our water is expensive (4800 gallons == $170, that was my Aug bill).

Anyway, this is a mostly PEX installation, and if PEX can be re-crimped, then separating the water supplies is trivial. If the PEX lengths that are too short to be trimmed and still reach, then it's only a little more complicated. But if the joints cannot be re-connected to new PEX, then there are a dozen + lengths/joints in series that I'll have to redo, which terminate in some adapters that look peculiar and might be hard to source.

[LarryHoward]

Sweating copper isn’t hard but can take a little practice. Lead solder was really easy to use but now we know it was a bad idea so make sure you use lead free. I have found it a bit trickier as it doesn’t flow as well. Watch a couple of YouTube videos and remember “clean and dry”. Clean means bright and shiny. Dry because water in the joint will keep parts below temp and solder won’t flow at 100C. (Boiling water). Use paste flux.

Close joints are slightly tricky as you need to heat a joint without melting the solder on an adjacent joint.

Never hurts to buy a short piece of copper pipe and a fitting or two and practice. If you get it wrong and it leaks, you can redo it easily. Valves can be a slightly bigger challenge because they are heat sinks and you have to get them hot enough without heating the seals enough to damage them.

Older Shutoff valves sometime have replaceable seals. You might take a look at that before replacing the valve.

[Ken Heaton (Salazar)]

Q: Can you "re-sweat" a new fitting onto the same copper pipe end that already had one? Or do you need to trim it and start clean?

A: No, you don't have to trim the soldered part off, just clean off excess solder and sand it (emery cloth) again. You don't have to get all the solder off, in fact having some left behind makes it a bit easier to re-solder, just get enough off that the parts fit back together, and are clean and shiny before putting on the flux and putting it back together again.

When soldering valves, have the valve open, and have a wet rag handy to cool the valve once you have finished soldering it.