UFH pipe layout design - any improvements?

[Tom]

Morning all - received the attached from WUNDA yesterday. Are there any obvious errors/improvements that you can see for this? I suggested to them that we could have the pipes for the main area on the right punching through the plant room wall beneath the fish tank (marked "6" on plan), but they seem to have put them through the wall in to the corridor. Also, the manifold for these pipes is in a different position to the other, which seems odd - but perhaps that's OK? I'm expecting to have the UVC etc on the left hand wall of the plant room - but haven't spent any sleepless nights worrying about this yet, perhaps I need to start. Anyway, would be very pleased to hear any feedback. Pipe spacing's are 150mm.

Cheers all

05054 Tom PIPE LAYOUT - A1.pdf

[RHayes]

Morning

 

Nice place you have there.  

 

I totally agree with your request to put the manifold serving the main area on the wall oposite the the fish tank and pipes running under that.  However this is assuming you are going to have fish that are possibley of tropical origin as your fish tank will get rather warm (unless it isn't floor standing).  Fish tank asside this would be a much better option for the hallway which has a massive bunch of pipes on that end.  Also with that 1 manifold being controled by one thermostat you won't need actuators.  Just a 2 port zone valve before the manifold which i'd recomend installing 1 for both manifolds anyway.

 

The other thing I would recomend strongly is a separate loop and thermostat control for your master en-suite. Like they have drawn it will mean you don't have heat to the en suite without the bedroom being on and you can't have different temperatures.  Also if you do put a thermostat for the en-suite id recomend having a floor sensor in the floor as then you can be sure of having a nice warm floor for your bare feet.  If you just base this on room/air temperature you can't be sure of having a warm floor.

 

I'd combine the 2 loops for the hall way to give you the spare port for the en-suite that way you haven't increased the size of the manifold.

 

As to having both manifolds in the same place, this is an option (left hand wall) and then runn the pipes for the main area straight across and under the fish tank.  This would remove the need for a separate loop in the plant room (if the need was there in the first place) as the plant room will be pleanty warm enough with both manifolds in there and you don't necessarily need an evenly warm floor in a plant room.

 

What size pipes is being used for the UFH loops?

 

Just a few thoughts.  I'm sure there will be others and different points of view.

Edited October 29, 2021 by RHayes

[Tom]

Great, many thanks for you reply. The pipe is 16mm by the look of it. I agree with your idea re the en suite, would make sense to have a floor probe here.

The quote includes 12 actuators - so I guess they planned for the manifold for the main area to be without them (the actuators being for the other manifold) - I don't understand what a 2 port zone valve does, can you expand? Why would you recommend this for both manifolds?

I could also run the loop for the spare beroom directly through the wall in to it, so reducing congestion in the hallway a little. Re this congestion, they suggest using insulation around the return pipes - is this necessary? What insulation should I consider?

[ragg987]

21 minutes ago, Tom said:

Re this congestion, they suggest using insulation around the return pipes - is this necessary? What insulation should I consider

What is the build and heat source? If a low energy build and using Ashp you will want flow temperature to be quite low and probably only 2 or 3 C lower than return. In this case don't see that the insulation would add much. And good to see you proposing 150 centres, this will allow you to keep flow temperature low, for an Ashp this will improve cop.

[RHayes]

15 hours ago, Tom said:

I don't understand what a 2 port zone valve does, can you expand? Why would you recommend this for both manifolds?

A 2 port zone valve (motorized zone valve, there are a few variations of name for the same thing) does the same thing as a manifold actuator but is is for the whole manifold and goes on the pipework feeding the manifold.  They will also have a micro switch on the that switches on when the valve is fully open and this can inturn trigger a pump or the boiler.

 

If you don't have actuators on the manifold serving the main area then you will definatly need a zone valve for that manifold otherwise you will get heat to that floor when anything else is on.  I recomend them for both manifolds to extend the life of the actutors on the manifold.  Without it the actuators will be trying to hold back flow when just the main area is calling for heat and over time this can weaken them and you get water creeping past and heating rooms that don't need it.

 

15 hours ago, Tom said:

Re this congestion, they suggest using insulation around the return pipes - is this necessary? What insulation should I consider?

Would be good to know what the build up of the floor is and also the floor finish.  We use armaflex insulation tape or a similar product to cover our pipes.  I did an output excersise once and be aware that this was approximate as there aren't any approved figures on this, but using the surface temperautre after the insulation as the water temperature and plotting a graph of the tried and tested systems at different pipe centres, I reckon that with both flow and return insulated at approximately 50mm centres, this would give you the same heat output per square meter as 150 centres un insulated.  I personally recomend doing the best you can to route pipework along different areas to reduce congestion and then insulating both flow and return transit pipework at least where there is congestion of more than 2 loops/4 pipes but why not all of them, it means the heat is being retained in the pipe until it gets to the room it is suposed to be heating.

[Tom]

Thanks for your input both, apologies for my late response.

 

On 29/10/2021 at 19:41, ragg987 said:

What is the build and heat source? If a low energy build and using Ashp you will want flow temperature to be quite low and probably only 2 or 3 C lower than return. In this case don't see that the insulation would add much. And good to see you proposing 150 centres, this will allow you to keep flow temperature low, for an Ashp this will improve cop.

Build is ICF and highly insulated, heat source: ASHP.

 

On 30/10/2021 at 10:51, RHayes said:

Would be good to know what the build up of the floor is and also the floor finish. 

300mm EPS below warm slab, UFH pipes within this in the living area - polished slab as the final floor, pipes in screed over the top of the slab in the bedroom/snug etc areas - with mixture of tiles/carpet/wood floor finishes. I'll see if I can ease the congestion in the corridor - but I guess from your observations I could get away with uninsulated flow/returns as long as they are at 150mm centres - esp if temps are going to be low as ragg987 points out?

[ProDave]

Forget the loop for the inner coridor. Total waste, it will never get cold enough there to call for heat.  It will get plenty of heat just from all the pipes passing through.

[Tom]

Thanks all for your input. Attached are the revised plans from Wunda - I've kept the loop in the corridor as there is a chance if the bedrooms aren't occupied (when children fly the nest etc), there might not be much of a flow going through to those loops. Anywho, will go for the attached unless there is anything else we could change?

Thanks all

05054 Tom PIPE LAYOUT - REV A - A1 .pdf

[JohnMo]

Why have loops in hall and utility, there are tonnes of pipes going through that space already.  As Dave says your corridor is in the centre of the house, it will borrow heat from elsewhere.  Strongly suspect the hall and utility will suffer from overheating, as designed.

 

Would not have UFH pipes under beds either.

 

For the time it takes I would download loopcad of free trial and review the design yourself.

 

You tell Wunda sell pipe!

 

Have considered 200mm pipe spacing?  Are you having electric towel rads in bathrooms?  For summer drying.  If I was doing it again I would do electric UFH in bathrooms.

[Tom]

Thanks, John. I guess the loops in the corridor and plant room can always be switched off though - better to have the option, no? Harder to add the pipes later when the screed is down!

[Dudda]

Are you growing Cannabis plants in this corner?

 

 

They'll run straight through but I wouldn't worry as the plumber will sort out of few of these types of minor issues out onsite.

[Tom]

Well, it is the plant room...

[Nickfromwales]

 

@Tom

Easy to mitigate with insulation on the flow pipes where they congregate   Don’t let them pick on you OK  

[Gus Potter]

12 minutes ago, Nickfromwales said:

 

@Tom

Easy to mitigate with insulation on the flow pipes where they congregate   Don’t let them pick on you OK  

That is some photo. Just wondering how the the screed / concrete is supported through the opening in the left photo.. it's got a bit of work to do to get past the pipe insulation..and what is that small portion of stud wall sitting on in the left photo?

 

Like the curved walls. Right hand photo looks impressive with neatly clipped pipes.

[Nickfromwales]

 

I separated the pipes and marked the sole plate to avoid ‘unwanted water relief holes’. 
The studs all reside on a course of blue bricks, so there I just packed out with timber and punched 2x 200mm concrete screws down, through liquid screed and into the concrete slab beneath

12 minutes ago, Gus Potter said:

.. it's got a bit of work to do to get past the pipe insulation

Trust me, with liquid screed the challenge is to stop it going anywhere it’s not supposed to  

It will have 100% encompassed those pipes with ease. The builder used mastic / sealants and I also used foam to create a dam in the openings where the flow of the liquid screed needed to be arrested.