I’d like to do some “creative” plumbing to experiment with some tankless WH configurations. I’m using Zurn pex with the black copper crimp rings (my first time using pex). I need a 4-way connector with 3/4″ ports on all four connections. Does such a thing exist, or will I have to use a small manifold?
Thanks,
Michael
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Replies
Get a copper 4 way & sweat some copper to PEX fittings in, or a cast iron 4 way with threaded NPT to PEX if you just want to experiment.
Joe H
What are you building?
Martin
It's a plumbing experiment. The plan is to configure three electric tankless water heaters in various configurations. I want to try series and parallel connections, even use one small unit just to preheat the inlet for a slightly larger unit. I'll also finesse the volume and flow by using various sizes of pex for the conduit. If you look at the attached drawing, you can see that I can open and close valves in a combination that will allow me to isolate any one unit, put up to three units in series, or put any two units in parallel, or create a series-parallel circuit. (Sorry about the attachment size. I drew this in MS paint and wasn't sure whether it would retain any clarity if I compressed it).
Feedback welcomed.New knowledge is priceless.
Used knowledge is even more valuable.
What are you trying to archive with this set up and were are going to use it?
Curiosity killed the cat!!!Martin
"What are you trying to archive with this set up and were are going to use it?"
I'm going tankless with my current remodel. I didn't want a gas unit and I'm just not convinced yet that a huge electric unit is the most practical alternative. The remodel will include a bath/shower combo, a stand alone shower, a whirlpool tub, laundry, dishwasher, and sinks. There will be times when the demand for hot water will be large. But most of the time, it won't be. We rarely have simultaneous needs of hot water, so I want to see how closely I can match the power consumption to the need. It's assumed that this is already being done by controllers which power the heating elements. But the logic circuitry does not monitor flow; it monitors temperature rise. While there is a direct correlation of flow and temperature rise in a single unit, that may not necessarily be the case when multiple units are configured in a supplemental fashion.
I have no idea whether this scheme will produce any meaningful results. I have researched this quite a bit and gotten feedback from many people who use tankless units. The results are so conflicting that you begin to wonder if people are talking about the same thing.
"Curiosity killed the cat!!!"
Yeh, but it also led us to electricity, flight, and lite beer. ;)New knowledge is priceless.
Used knowledge is even more valuable.
It will probably take a 200 amp panel to run this setup.
And it will make your meter spin.
"It will probably take a 200 amp panel to run this setup."
I have a 200 amp panel.
"And it will make your meter spin."
Only when it's being used and only as demand requires. What do most of us need hot water for? To clean stuff! Our laundry, our dishes, and ourselves. Any heat developed beyond that requirement is a total waste of energy and money. How much hot water is really needed for the laundry? Usually not as much as we think. In fact, with the right detergents, there's a lot of clothing that will come clean with no hot water at all. Some clothing is actually harmed by hot water.And dishes? Some dishwashers heat their own water and newer appliances are requiring less water. Advances in non-stick cookware and dishwashing liquids also play a role. Some people are switching to paper plates to avoid dishwashing altogether. And some people eat out so much that it has little relevance to this issue.So what about bathing? Do you ever take a bath or a shower with ONLY the hot water running? Most people don't. Most of us have to temper it with cold water. Otherwise it gets too hot. Of course, we may use hot water to wash our hands, shave, brush our teeth, etc. But those activities usually require a minimal flow rate and a minimal temp increase. In other words, I suspect that we insist on having more hot water available than we can comfortably get by with. I hope to prove that.
Obviously, hot water used for space heating is an entirely different realm.
New knowledge is priceless.
Used knowledge is even more valuable.
I was in a hurry when I responded to your post, I should explained more carefully.
Small tankless heaters use two 50 amp breakers.
Larger ones may have three 40 amp or larger breakers.
With three heaters like you suggest it may total 340 amps.
This number of breakers will take up 16 spaces in your panel.
Most 200 amp residential panels don't have this much extra room.
If you use a seperate 200 amp panel it still might be too much load.
Check carefully the electrical requirements of the heaters you intend to use.
I'm just trying to save you from some problems.
It has been said that electric is not user friendly for heating large volumes of water.
"Check carefully the electrical requirements of the heaters you intend to use.I'm just trying to save you from some problems."
I appreciate the feedback. One heater is a 9kw that requires one 40A breaker. The other two units are 14kW each and require two 30A breakers. Therefore, the total potential load is 160A on my 200A/42 space panel. However, even the largest single electric units seldom require more than 120A, even when fully loaded.
Multiple units can exponentially increase the current draw if the demand placed on them requires it. But I believe that with the proper configuration -- and reasonable expectations -- that I can actually decrease the total current draw exponentially. Remember, with tankless units it's all about "temperature rise" (i.e. boosting the inlet water temperature just high enough for sufficient cleaning and comfortable bathing -- nothing more). Anything beyond that is not only wasteful, it's entirely unnecessary.
Does it take triple digit amperage to achieve that? If the water is given more than one opportunity to absorb the heat, and is allowed to move through the system at a pace which will fully allow it to absorb the heat, I don't think it will take anywhere near triple digit amperage.
But...we'll see.New knowledge is priceless.
Used knowledge is even more valuable.
go with the manifold...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
"go with the manifold..."
Too late. When I inquired about a 4-way at the local big box, the young pimply-faced assistant said "We don't carry any. Maybe you could just put two tee's back to back, and on top of each other. Wouldn't that accomplish the same thing?" My aging gray matter desperately strained for a sufficiently technical response to counter the embarassment of overlooking such an obvious and simple remedy. But alas, I humbly conceded defeat to the young pimply-faced assistant and replied "That'll work!"
I hate it when that happens.
New knowledge is priceless.
Used knowledge is even more valuable.
If you use 3 tee's in a row than you have a easy manifold. It just depends how much flow you want to get.Martin
"you could just put two tee's back to back, and on top of each other. Wouldn't that accomplish the same thing?'
Since you were man enough to confess this, I'll join in.
Last week I sandwiched 1/2" plywood between 2 2x4s to build them up to match the width of a 4x4 post. When I was done I realized I could have just turned them on their side as I have done hundreds of times. Age does terrible things.
Give Energy Reduction a call Monday Am 412-331-4545 Mark should be able to hook you up.