Hep 20 Manifold

[TerryE]

2 hours ago, MikeSharp01 said:

Is that on everything except drinking water and what do you think the annual running cost is for your usage?

Yes, everything apart from cold drinking water, as tea and coffee make better with the soft water. 

 

Electricity on our current tariff is about 10p / day and filters are maybe £15-20 per 3 months so around £100 p.a.

 

PS. Mike, it looks like I'm not the only one to cross post on topics. 🤣🤣

Edited June 12, 2022 by TerryE

[MikeSharp01]

55 minutes ago, TerryE said:

Electricity on our current tariff is about 10p / day and filters are maybe £15-20 per 3 months so around £100 p.a.

Does that include the salt blocks. We looked into it for here, millstone manor, and it was £100s per year so we decided against it although I plumbed for it so if needed we could do it.

[TerryE]

Oops, I am the Wally: my answer was to the MVHR post that I was working on. Sorry. 🤣

 

The only running costs for the Harvey is the salt blocks as you say.  Clearly usage depends on your water consumption and water hardness which will vary dramatically depending on geography and hence from household to household.  We buy the 12 packs for £80 odd and these last around 4-6 months, IIRC. I can check with Jan what we use, as she does the reordering. 

[JanetE]

12 packs of salt blocks last a year. They are £72 from: Greens, https://water-systems.co.uk/

[MikeSharp01]

55 minutes ago, JanetE said:

12 packs of salt blocks last a year. They are £72 from:

So not that much really!

[MortarThePoint]

On 12/06/2022 at 12:54, MortarThePoint said:

A 10m run of 22mm pipe has a dead volume of about 2.5litres so a 10l/min shower would take 15seconds to heat up, presuming the thermostatic valve runs pure 'hot' until actually hot water arrives. 23 seconds for 15m. It's a waste if water, but not too much time. It feels like under 10s is awesome, under 20s, desirable and under 30s acceptable.

 

I've no idea what an pleasant shower flow rate is, but have read figures like 12l/min down to 6l/min for Part G.

 

According to this calculator, 15m of 15mm OD 11mm ID pipe needs 3bar pressure to supply 5l/min which if the shower is running at 50/50 is at total 10l/min. A 22mm OD 17.7mm ID pipe needs under 0.2bar.

 

Can anyone report good results having run over 15m of 15mm pipe to a shower?

 

OK so that calculator is guff. I've got headloss data for Hep2o and at 6l/m the headloss is 1.5bar/10m for 10mm pipe, 0.14bar/10m for 15mm pipe and 0.016bar/10m for 22mm pipe. I've checked this against another source (Pegler pip, OK not plastic but fine) and it roughly tallies.

 

Flipping to work out what flow rate creates a 1bar pressure loss over 10m:

   10mm   0.08kg/s   5l/min (est)

   15mm   0.31kg/s   19l/min

   22mm   1.07kg/s   64l/min

[Nick Laslett]

On 12/06/2022 at 10:59, MortarThePoint said:

 

I'm starting to lean in that direction. 4no. direct pipes to taps would have 8 joints (4 at manifold, 4 at taps) where as 1 pipe branching at a sub manifold would have 10 joints (1 at main manifold, 5 at sub manifold and 4 at taps). If each joint is a worry, I 'only' increase the worry by 25% but massively reducing the routing headaches. If I'm worried enough, I could always put the sub manifold into some form of draining sump. Their plastic manifolds are all 22mm in though and only up to 3no. 15mm out.

 

Hello,
@MortarThePoint, what did you do in the end? 22mm to a sub-manifold?

 

I have 3 bathrooms and six existing duct runs in the insulated foundation, 1 for hot and cold to each bathroom. My plan was to feed a 22mm pipe down each duct, then have a sub-manifold in each room to feed toilet, shower, bath and basin. 

 

I wonder if a 15mm pipe is too small to be the sole supply to a whole bathroom?

 

Each bathroom is 10m from the plant room. 

 

@Nickfromwales what do you think? How many feeds is it feasible to run from a 15mm pipe? When do you need to step up to 22mm?

The main comes into the plant room, where there would be a hot and cold manifold to feed the 6 sub manifolds and direct run to kitchen and downstairs loo. 

 

Edited October 19, 2022 by Nick Laslett

[Nickfromwales]

5 minutes ago, Nick Laslett said:

Hello,
@MortarThePoint, what did you do in the end? 22mm to a sub-manifold?

 

I have 3 bathrooms and six existing duct runs in the insulated foundation, 1 for hot and cold to each bathroom. My plan was to feed a 22mm pipe down each duct, then have a sub-manifold in each room to feed toilet, shower, bath and basin.

 

I wonder if a 15mm pipe is too small to be the sole supply to a whole bathroom?

 

@Nickfromwales what do you think? How many feeds is it feasible to run from a 15mm pipe? When do you need to step up to 22mm?

 

 

Defo do NOT run 22mm radial runs, unless you're using a hot return setup? The delay in getting hot water out of the basin taps would be painful. Those would be huge dead legs, and very very wasteful in unused water having to be first discharged, and then the amount of lost DHW left to go cold in that increased volume of dead leg the same.

Bear in mind that you'll only ever be using one outlet at a time, so a 15mm feed, fed off a primary manifold from 22mm pipework, will be more than suffice afaic. Also bear in mind that most modern taps / shower valves etc have a max flow rate restricted by manufacture, so you can only get a certain deemed flow rate out of them anyways, waaaaaay less than a 22mm pipe has to offer.

Edited October 19, 2022 by Nickfromwales

[Nickfromwales]

FWIW, I think satellite manifolds are a bad idea.......unless you have a mansion and a HRC  👎

[Nick Laslett]

10 minutes ago, Nickfromwales said:

FWIW, I think satellite manifolds are a bad idea.......unless you have a mansion and a HRC  👎

Thank you for the feedback. I agree. But I failed to plan adequately before the pour. So in my case it is 2 satellite manifolds vs 7 direct runs per bathroom. Might be able to direct feed one of the bathrooms. 
 

I get the message about 22mm for the hot. 

Edited October 19, 2022 by Nick Laslett

[Nick Laslett]

@Nickfromwales Okay, might have forgotten my thinking from last year when working on the foundation. I have 50mm ducts, so I would but 2x15mm, 1x10mm pipes thru the duct to direct feed the shower, bath and basin. And not need a satellite manifold. 
 

Any tips for how to feed the pipes thru the duct? Altogether, one at a time?

Edited October 19, 2022 by Nick Laslett

[MortarThePoint]

27 minutes ago, Nick Laslett said:

@MortarThePoint, what did you do in the end? 22mm to a sub-manifold?

 

I'm feeding most of my basins with 10mm direct from the plant room. 5l/min feels fine (a pint in 7 seconds) and mixed with cold the flow would be greater , e.g. 10l/min if 50/50.

 

The numbers suggest 15mm @ 10m gives bags of flow for a shower. For a bath, dead volume isn't really relevant as you run all the water before using it. For 10m, 15mm has a dead volume of 1.1 litres (7sec at 10l/m shower) whereas 22mm has a dead volume of 2.5 litres (15sec at 10l/m shower).

 

Bath filling time is then the only other time based factor. As @Nickfromwales says most taps have a limited flow rate. I don't know what taps you are thinking of using, but I find it difficult to get data.

 

"A flow rate between 10 and 15 litres per minute is considered acceptable but can be improved. A flow rate that is above 15 litres per minute will be regarded as good." [Plumbworld]

 

15mm pipe drops around 1bar with a flow rate of 15 litres/min over 10m with a couple of bends so that should be fine.

 

I like to run the numbers to understand it, but put much more sway in what people like @Nickfromwales have learnt to work.

 

[MortarThePoint]

I haven't installed yet. Bought a reel of 22mm before learning/deciding 15mm will be OK. Might be able to use to service the garage with cold water.

[Nick Laslett]

22 minutes ago, MortarThePoint said:

 

I'm feeding most of my basins with 10mm direct from the plant room. 5l/min feels fine (a pint in 7 seconds) and mixed with cold the flow would be greater , e.g. 10l/min if 50/50.

 

The numbers suggest 15mm @ 10m gives bags of flow for a shower. For a bath, dead volume isn't really relevant as you run all the water before using it. For 10m, 15mm has a dead volume of 1.1 litres (7sec at 10l/m shower) whereas 22mm has a dead volume of 2.5 litres (15sec at 10l/m shower).

 

Bath filling time is then the only other time based factor. As @Nickfromwales says most taps have a limited flow rate. I don't know what taps you are thinking of using, but I find it difficult to get data.

 

"A flow rate between 10 and 15 litres per minute is considered acceptable but can be improved. A flow rate that is above 15 litres per minute will be regarded as good." [Plumbworld]

 

15mm pipe drops around 1bar with a flow rate of 15 litres/min over 10m with a couple of bends so that should be fine.

 

I like to run the numbers to understand it, but put much more sway in what people like @Nickfromwales have learnt to work.

 

Thank you for the reply. I like how thorough you are with your thought processes. I have found many of your threads and posts very helpful. You have a knack for creating interesting discussions. 
 

I appreciate that there are a number of variables that effect the water dynamics. My take away is that a 15mm pipe over 10m, could be tee’d and supply two standard showers simultaneously with enough hot water. But if you can, give them both there own direct feed. 

 

[Nickfromwales]

3 hours ago, Nick Laslett said:

Thank you for the feedback. I agree. But I failed to plan adequately before the pour. So in my case it is 2 satellite manifolds vs 7 direct runs per bathroom. Might be able to direct feed one of the bathrooms. 
 

I get the message about 22mm for the hot. 

Tee the bath and shower at the room, with the T’s behind the bath panel or vanity unit, and that drops you to 5.

[NewToAllOfThis]

Thanks to help from Nick, I think I have now worked out all the connections.

I had already installed 15mm pipe before realising I could have used 10mm to the taps.

I have put dedicated runs to both toilets as it gives the option to use some form of rain / waste water harvesting in future.

 

[MortarThePoint]

But for it being super weird, there is a lot of sense to having the manifold on the ceiling shooting out its however many pipes horizontally off to where ever they need to go. Not very accessible (would need steps) but avoids the need to send each pipe up about 1000mm and then through a right angle into the ceiling void of the room next door.

 

Feels too weird though. I could just imaging the look on a professional's face if they saw it.

[Nickfromwales]

2 hours ago, MortarThePoint said:

But for it being super weird, there is a lot of sense to having the manifold on the ceiling shooting out its however many pipes horizontally off to where ever they need to go. Not very accessible (would need steps) but avoids the need to send each pipe up about 1000mm and then through a right angle into the ceiling void of the room next door.

 

Feels too weird though. I could just imaging the look on a professional's face if they saw it.

Have you been at the cooking sherry again?

[TerryE]

@MortarThePoint, one of the side effects of dipping into threads when poked is that you often forget what you said to who, so I had to refresh myself on this thread.

 

I got an excellent resource from on old boy that has now been dead for over 5 years that have all of the static and dynamic flow tables and formulae to make sure that everything was balanced and had adequate flows.  In short we have a 3 bar mains feed which is at ~2bar for max realistic flow through the water filter, manifolds, etc.  At this head unless you've got pathologically long runs 10mm is easily enough for toilets and basins.  15m for high flow showers and baths.  Nothing needs more for a 1-1 run. 

 

I made my Clapham junction analogy in an earlier post.  We rans all of the pipe runs back into the GFL toilet ceiling space with enough tail left on each run to comfortably reach the manifold (my service cupboard was built and split off the toilet space, but the framing and bifold doors were only added after everything had been fitted).  I also put the cold manifolds on a separate wall in their own access panel (above the Gerberit wall-hung toilet mount, and now hidden behind a nice poster of a Cretan harbour scene 😊).  This meant that all of the CW tails ran in one direction and the HS tails at 90° to this below above them.   Once completed, even Jan agreed that floor void scene did look nicely laid out. 

 

We've got evoJoists so its quite easy to plan runs both parallel to and cross joist.  And there it lots of space to make the 90° horizontal to vertical turn into the manifolds. 

 

No the pipe runs aren't accessible, but so what?  All pipe fittings are.

 

[Chanmenie]

When reducing to 10mm from the manifold 15mm female can you just use a 15-10mm reducer spigot pushed straight into the manifold 

Sorry if it’s a daft question this plastic stuff is all new to me 😀

[Thorfun]

23 minutes ago, Chanmenie said:

When reducing to 10mm from the manifold 15mm female can you just use a 15-10mm reducer spigot pushed straight into the manifold 

Sorry if it’s a daft question this plastic stuff is all new to me 😀

that's what we did

 

 

there was some discussion about it as @Pocster found removing them a pain in tight confines but @Nickfromwales said that it was all ok and so I just went ahead and did it! here's that discussion

 

 

[Chanmenie]

Brilliant thanks @Thorfun

I had read quite a bit of that thread but missed that bit, probably fell asleep as it’s 23 pages in and a monster thread, very informative in places though 😀

Edited December 26, 2023 by Chanmenie

[Thorfun]

15 minutes ago, Chanmenie said:

Brilliant thanks @Thorfun

I had read quite a bit of that thread but missed that bit, probably fell asleep as it’s 23 pages in and a monster thread, very informative in places though 😀

Yep and it goes off-topic quite often! 😂

[Chanmenie]

5 minutes ago, Thorfun said:

Yep and it goes off-topic quite often! 😂

Hardly surprising with that bunch of contributors 😂😂

[Nick Laslett]

10 hours ago, Chanmenie said:

Brilliant thanks @Thorfun

I had read quite a bit of that thread but missed that bit, probably fell asleep as it’s 23 pages in and a monster thread, very informative in places though 😀

 Yes, this fitting worked for me.  Between Thorfun’s thread and MortarThePoint Hep20 threads, a lot of pushfit plumbing questions are very well covered.