Is a satellite manifold a crazy idea?

[alfaTom]

Our build is coming along nicely and I'm getting to the stage where I lie awake for hours thinking about pipes.

 

I've read plenty of topics on here about radial manifolds to reduce amount of water that needs drawing off for hot supply, plus also hot return circuits.

I kinda want both, purely because I want the water to be hot quickly and I don't want to put in one solution and find it's not enough later.

 

My problem is I don't think I could get an HRC on each radial leg without going totally overboard, so I'm thinking about satellite manifolds instead.

I can put them in fairly easy-access locations in bathrooms so joints/leaks are less of a concern, plus I can run the HRC off the end of the satellite manifold back to the UVC.

 

Is a satellite setup with HRC a wise idea? I can't see why having one manifold fed by a 22mm supply vs a few manifolds off a 22mm supply would be any different but I am not a plumber, just a hep20 enthusiast😂

 

A UVC will supply DHW, and the mains is being replaced from 15mm copper to 32mm MDPE, which means I don't know the mains pressure yet. I do know the HPPE was replaced in recent history so I am hoping the communication pipe is at least 25mm. (Keeping 32mm as cost difference is tiny and would rather not dig it up again later if water pressure drops in the area over time...) 

 

Picture for attention: I'm aware I'm missing lots of parts but as a "map" of what we're after hopefully it helps.

 

The run to the family bath section will probably be 7-8 metres, but a big steel to support the opening stops me running all the individual pipes through and I'm looking for a "less is more" approach.

The run to the master ensuite may be closer to 12-14 metres so would benefit from an HRC I think.

Kitchen and the W/C is about 2 metres from UVC, and the utility about 4 metres.

 

Layout of house (X is hot water point downstairs, triangle is hot water point upstairs)

 

Thoughts?

[Temp]

I haven't looked at your plans in detail but we used two remote manifolds. We wanted very high flow rate showers and ran 28mm from our thermal store to a home made manifold near each of the main bathrooms. Then 22mm from there to the showers. 

 

Regarding return loop pipes..  think about hot taps where you want hot water to appear quickly and run the return from as close to those as possible. We have a basin in a WC and the return pipe connects about 8ft away from the tap. Even that's too far away from the tap. You've washed your hands before the hot comes out. The return on the kitchen tap is right under the sink at that's much better. 

 

Some people put PIR sensors in remote WC so the loop pump starts when they enter rather than running all the time. You can also put timers on them so they don't run at night if you want

 

Builders don't insulate hot pipes and the return nearly well enough or even at all in some places. Consider taller stand offs to space pipes away from walls/floors a bit further than normal so you can get more insulation around them? 

[JohnMo]

We have a long thin house and from UVC to shower is about 15m. It's run to an intermediate manifold about 7.5m each way (UVC - manifold - shower) running the shower tonight with HWC pump off (for 12 hrs) it took just over the time to take my clothes off to be hot. 15mm pipe everywhere.

 

Sorry you have had way too much time thinking. Simplify, one hot manifold, one cold, you only need one feed to each room then branch from there. 

 

Keep 22mm well away from hot water supplies other you will get bored waiting for hot water.

 

We have HWC it goes to the furthest room and through the manifold back to the cylinder. Run it on timer and thermostat.

[Kelvin]

The Rehau ‘smart’ manifold system standard install is to fit the manifolds in the room where you need the water but that’s a lot of manifolds and all the required fittings plus you need make them accessible. Our plant room is in the middle of the house with relatively short runs to the bathrooms kitchen and utility room so we have two of their 9 outlet manifolds (4 hot 5 cold in each) Very compact so take up little space. 

 

Like @JohnMo our showers are hot by the time you’re ready to get into them. 15mm pipe. 

[alfaTom]

Some good replies here - thanks everyone!

Sounds like a satellite/remote/sub manifold will work for my situation, just need to KISS.

 

On 28/11/2024 at 21:09, JohnMo said:

Sorry you have had way too much time thinking. Simplify, one hot manifold, one cold, you only need one feed to each room then branch from there. 

 

A classic buildhub problem being left with too much time. This sounds similar in principle to what I'd be doing though I think. Two manifolds to "branch" in the further rooms and everything else off one local one.

 

My main concern had been trying to keep everything radial. I think 22mm to feed remote manifolds with the HRC on the manifold via PIR or timer so the larger volume of hot water in the 22mm pipe gets circulated to mitigate that issue. I already have PIRs in place to activate the LED "pee" lights so you don't get blinded at night time so that could work...

 

[Andehh]

Fine to do that with the cold.

 

Don't do it with the hot circulation route. You need the circulation route within a couple of feet from the tap.

Our main bathrooms are within 2ft and it works perfectly... Our kitchen is a out 10ft and the hot water arrives by the time you've finished washing your hands. Still a great decision though, as without it we'd be 30m + away.

 

 

[JohnMo]

10 hours ago, alfaTom said:

Two manifolds to "branch" in the further rooms and everything else off one local one

Not really what I was saying. By branch I mean simply tee off to the user in the wet room. So central manifold, one leg goes to bathroom, within bathroom, that single pipe tees off to shower, bath, sink etc. dump the idea of lots of local manifolds.

 

You are making issues by complex design, then making a hot water circulation system way to complex to compensate.

[Kelvin]

2 hours ago, Andehh said:

Fine to do that with the cold.

 

Don't do it with the hot circulation route. You need the circulation route within a couple of feet from the tap.

Our main bathrooms are within 2ft and it works perfectly... Our kitchen is a out 10ft and the hot water arrives by the time you've finished washing your hands. Still a great decision though, as without it we'd be 30m + away.

 

 

One of the things we learned during COVID on hand cleanliness (pathogens anyway rather than anything else) it’s the soap and length of time you clean (at least 20s) that cleans your hands not the temperature of the water. Consequently I’ve never bothered waiting for hot water since knowing that anywhere I go. 

[MikeGrahamT21]

1 hour ago, Kelvin said:

One of the things we learned during COVID on hand cleanliness (pathogens anyway rather than anything else) it’s the soap and length of time you clean (at least 20s) that cleans your hands not the temperature of the water. Consequently I’ve never bothered waiting for hot water since knowing that anywhere I go. 

temperature does have importance, during my many years of caring for my late wife and doing IV treatments at home, we were told to only ever wash hands in cold water, since warm water opens your pores which can allow any nasties to hide away, since then I’ve always washed hands with cold water

[Gone West]

5 hours ago, MikeGrahamT21 said:

temperature does have importance, during my many years of caring for my late wife and doing IV treatments at home, we were told to only ever wash hands in cold water, since warm water opens your pores which can allow any nasties to hide away, since then I’ve always washed hands with cold water

Back in the seventies I was told a similar thing by a chemist at work. Don't wash your hands with Swarfega, use washing up liquid and cold water so the skin pores don't open. He said Swarfega was carcinogenic in those days.