Designing Expansion PEX Layout and Brands to Use

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Wren

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Now that I'm finishing up the drains I'm looking to install the water supply lines. I'm going with PEX A pipe. Is there a good resource for designing the best system for a house like ours? I'm somewhat familiar with the old-style trunk and branch system as well as the logic system, but am not sure what would be the best option for this house.

It's a single story on a crawlspace. I've attached a drawing. My main concern is that it's quite a distance from the hot water heater to the full bath and am interested in what would be the best way to not to have to wait for a long time for hot water for the lavatory, tub, etc. While the kitchen is fairy close, the half bath is farther, but it probably won't get used that much so waiting for hot water for the lav. isn't a really big concern

Also, as for brands, the big box near me carries Apollo while I would have to mail order Upanor, etc. Is there a significant difference between brands?

I've already purchased a DeWalt expansion tool and want to get started.

I'm sure that I will have many more questions soon.

Any insights or advice would be appreciated.

Thanks!

Hgu888g.jpg
 
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wwhitney

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First question on the hot side, can you move the water heater closer to the fixtures?

Cheers, Wayne
 

Breplum

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I recommend a 3/4" hot water loop with recirculation, ideally, with pushbutton activation for the pump. Branches from the loop would be 1/2".
If you are not certificated by Uponor or any mfr, then warranty is potentially worthless.

Pex split 1.jpg
PEX split 2.jpg


Pics are 9 year olf Uponor on a single failed batch, that Uponor has now paid for full luxury high end home repipe in 2021.
 

Tuttles Revenge

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We use PEX A Uponor or Mr Pex brand depending on availability these days.

I concur with BrePlumb with installing a hot water recirculation loop with some form of push button / motion / aquastat switch that turns the pump on and off based on your needs.

hotcoldlayout.jpg
 
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Wren

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First question on the hot side, can you move the water heater closer to the fixtures?

Cheers, Wayne

The water heater could be moved to next to where the kitchen sink is. Currently, the water heater is in the crawlspace. I'm limited where I can put it in the crawlspace due to height constraints. Where it is now or the alternate location is about the only place it could be located. There really isn't a good place to put it between the full bath and the kitchen without making a closet for it inside the house. That's not out of the realm of possibility, but would require more planning.

We use PEX A Uponor or Mr Pex brand depending on availability these days.

I concur with BrePlumb with installing a hot water recirculation loop with some form of push button / motion / aquastat switch that turns the pump on and off based on your needs.

I think a recirculation system may be a little above my pay grade. :eek: Also, there is very limited access for future repairs under the full bath and the room one goes through to access it. I'll update the drawing tomorrow to list a couple of possible routes that the pipes could run, but I'm very limited by the (no room to)crawl space the house is on.

While I'm working on the drawing, what would be the next best setup after a recirculation system for the hot water?
 
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wwhitney

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Next to the kitchen sink is definitely a better location for the hot water heater, as you can see it's 10' to 12' closer to every fixture.

As to the recirculation loop, it's not that complicated, you just hit the kitchen sink, then the tub, then the washer, then the lav in the half bath, and then loop back to the water heater. You can run the pipe for it now and deal with adding a pump later if you want to add the recirculation. The only downside would be that the half bath lav would get water a bit slower (unless you add recirculation) than if you did a trunk and branch and hit the lav sink with a shorter path.

Cheers, Wayne
 

Jeff H Young

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I recommend a 3/4" hot water loop with recirculation, ideally, with pushbutton activation for the pump. Branches from the loop would be 1/2".
If you are not certificated by Uponor or any mfr, then warranty is potentially worthless.

View attachment 79290 View attachment 79291

Pics are 9 year old Uponor on a single failed batch, that Uponor has now paid for full luxury high end home repipe in 2021.
I'd like to hear more about the PEX failure sometime . Also good point on the warranty by certified installers its about a 15 minute might be worth the OP s time to set up a class with the rep, its pretty basic but I could understand an owner wanting to get the cert . Probably take an hours time
 

Wren

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Here's an updated drawing showing the non-accessable areas of the crawlspace. I'm planning on running the pipes going to the full bath along the floor joists above the access trench. I dug that out so I would be able to get to the tub drain if I ever had an issue and so I can inspect the PEX tubing from time to time. From the tub/lav, I'm planning on going up then through the ceiling joists over to the washer with a T over and down to the WC. That's about the only way to run the supply lines so that they are accessible in the future.

If I were to put in a single dedicated line to the tub and lav in the full bath for hot water coming from a manifold at the water heater instead of a larger line as would be used in a truck/branch setup, would that help with hot water delivery to the full bath? I assume that it could be 1/2" to provide sufficient flow. I could run an additional line for the washer.

ZWIwduB.jpg
 

Jeff H Young

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1/2 inch for tub and lav sure! Won't be circulated though branching off near w/h
 

wwhitney

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So can you run through the ceiling joists to get from the half bath lav to the washer?

If so, for the hot side I'd suggest three separate 1/2" runs from a manifold at the water heater: one for kitchen sink, one for tub/lav, and one for half bath lav, then washer.

If not, it's a question whether to run a separate 1/2" to the washer, or to just extend the one from the tub/lav. The latter option would only be a problem if you run the washer while using the tub/shower. [And in theory the washer doesn't care how slowly it gets hot water, so you could install a flow reducer at the washer so that it doesn't draw water as quickly and has less of an impact on the tub/shower.]

Cheers, Wayne
 

Taylorjm

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If all your worried about is turning on the bath faucet and waiting for hot water, then put in a small electric point of use water heater under the sink. it will give you a gallon or so of instant hot water for washing hands, etc. but will have to wait longer to more than that. Since usually you just use warm water, and not hot, then you will effectively have at least 2 gallons of warm water instantly. The tub you will have to wait, but that's not a big deal. You turn on the shower, let it run until it gets warm.
 

Wren

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So can you run through the ceiling joists to get from the half bath lav to the washer?

If not, it's a question whether to run a separate 1/2" to the washer, or to just extend the one from the tub/lav. The latter option would only be a problem if you run the washer while using the tub/shower. [And in theory the washer doesn't care how slowly it gets hot water, so you could install a flow reducer at the washer so that it doesn't draw water as quickly and has less of an impact on the tub/shower.]

Cheers, Wayne

Unfortunately, no. The full bath was constructed after the main part of the house and was built as a lean-to and has a lower ceiling than the main structure.

Running the washer while showering isn't a big concern althogh I'm liking the idea of running a separate hot water line to the washer from a manifold at the heater so there is never an issue.

If all your worried about is turning on the bath faucet and waiting for hot water, then put in a small electric point of use water heater under the sink.

It's not feasable to do so. There's no place to put it as we're using a pedestal sink.
 
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Wren

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I decided to go with Uponor and found a supplier that offered fast shipping and free returns.
 
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Taylorjm

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So are people still using the uponor brand even after the big cracking fiasco? Makes me kind of leary, but then I guess it could happen to any brand in 10 years, which is also scary. At least with copper it has a reputation of being reliable for many many years, but pex is so much easier.
 

Wren

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So now the boss is interested in a hot water loop for at least the full bath. With the limited access in part of the crawlspace, what would be a good layout for the lines to the full bath? I could either loop over to the half bath, or not as it won't get used much.
If I were to run a hot water pump, I would be interested in returning it back to the water heater.
Any inputs on what the best way to go would be appreciated.
Thanks!

So are people still using the uponor brand even after the big cracking fiasco? Makes me kind of leary, but then I guess it could happen to any brand in 10 years, which is also scary. At least with copper it has a reputation of being reliable for many many years, but pex is so much easier.

From what I've seen Uponor is still the prefered brand.
 

Tuttles Revenge

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I would pull a recirc loop back from your accessible shower. The other bathroom will still benefit from drawing hot water from that loop. It will likely see hot water in under 30 seconds, but more likely 10sec. This is basically how I would go about it.

All recirc systems should have some means of cycling the pump. My preferred method is an aquastat, that turns the pump on when the return line cools off. Some people prefer a switch in room that cycles the pump on when its asked for. A physical switch or a motion detector works depending on how interactive you want to be.

With a well insulated loop, the water heater location really doesn't matter as long as the pump and the length of the loop are matched up.

Hot Water Loopage.jpg
 

wwhitney

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I would pull a recirc loop back from your accessible shower.
For an application like this, what are the pros and cons of a dedicated 24' long return line, vs a point of use pump that dumps the hot water back into the cold line?

If the pump is manually activated, is there any concern about stale water in the recirc line if it doesn't recirculate for weeks or months for some reason?

How about pump location with a dedicated return line? If the pump is near the lav, and only runs until hot water reaches the pump, then I don't see any energy cost to the recirculation (other perhaps than foregoing washing your hands with cold water). The water going into the recirc line would otherwise have gone down the drain.

If the pump is at the water heater end of the recirc line, and runs until it sees hot water, then I think the standby losses of the 24' of hot water line to the full bath get doubled. Of course, this is more about pump controls location than actual pump location.

Lastly, how about pipe sizes in the diagram above? I can see supplying the kitchen sink with a separate 1/2" line from the tank, as it's so close. And the spur to the half-bath is 1/2". Is 1/2" adequate for the supply to the full bath, with an extension to the washer? Or a 3/4" supply to full bath and washer, with a 1/2" return line?

Just thinking this through out loud.

Cheers, Wayne
 

Jeff H Young

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So are people still using the uponor brand even after the big cracking fiasco? Makes me kind of leary, but then I guess it could happen to any brand in 10 years, which is also scary. At least with copper it has a reputation of being reliable for many many years, but pex is so much easier.[/QUOT

Im pretty old school , love copper have done some pex and cpvc but have no tools and rarely do pex.
copper has a reputation to last many many years and so does pex so what does that mean? they are both good to degree.
Dont know if youve ever worked in plumbing but copper leaks arent rare no no not at all , millions and milions of dollars of water damage is caused by copper leaks . all of us have repaired copper leaks.
Yea Pex is easier and cheaper much cheaper. with a careful professional installation I dont have much fear of pex but still concern but same with copper . I prefer copper for sure but the margin of preferance isnt as great as the importance of a proper build .
 
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