Can a slab be too thick to have UFH pipes in it?

[Dan F]

3 hours ago, Thorfun said:

It's interesting that you mention powering independently rather than parasitically helps. I am just doing more reading on 1-wire and was interested to know the benefits of one over the other but I've yet to get that far in my reading.

 

I'm using all 3 wires, read that it helps with reliability.  Also making sure i connect ground from end-to-end (this is easier if you make sure you buy a cable with drain wire).

 

3 hours ago, Thorfun said:

 

I think I'll go for the approach of bringing a conduit near to a wall with back plates. those back plates could always be switches and Loxone seem to say that you can then use the other pairs of the CAT 7 cable for the switches.

 

You can connect behind light switches, but if light switch is 1m high that limits length in slab or makes your branches longer.   I personally recommend a dedicated 1-wire bus that is not mixed with tree cabling.  It means you can keep it as short as possible just going point-to-point where you have 1-wire sensors, can keep branches as short as possible,  and also means that your tree cabling topology can be different and not a strict bus which can come in very handy.

 

3 hours ago, Thorfun said:

so was thinking of running the probes to the location where the switch plates would eventually be. seemed quite a sensible idea.

 

Doing this is still a good idea, regardless of it you do/don't use dedicated 1-wire bus.

 

[jack]

12 minutes ago, Thorfun said:

doubt I need that loop in the WC but I figured what the heck!

 

That's a very short loop compared to the others. I know you're running this all as one zone, but why not make the WC loop an extension of one of the shorter loops?

 

And what about routing around your comms room so that it isn't heated (although if you plan on cooling the slab in summer, it might help there!)

 

Re: the gym, I can't imagine working out in a well-insulated house. It's amazing how warm you get even just moving stuff around. I was in our bedroom yesterday installing some shelves and it was borderline unpleasant even though the room was probably only 21 or 22 degrees. I guess you can turn the heating off or down on that loop if needed.

[Thorfun]

17 minutes ago, jack said:

Re: the gym, I can't imagine working out in a well-insulated house. It's amazing how warm you get even just moving stuff around. I was in our bedroom yesterday installing some shelves and it was borderline unpleasant even though the room was probably only 21 or 22 degrees. I guess you can turn the heating off or down on that loop if needed.

so, when it says 'Gym' what it really means is a golf studio. I'm definitely not a gym person but I do like to swing a golf club so the plan is to have a net setup so I can practice during the winter etc.

 

your point is also valid for the music room as when the band rehearse in there it will also get a bit warm with the amps running etc. as such, I am tempted to zone the basement and pretty much just turn off all the rooms except the games room as the equipment/activities in the other rooms will heat them.

 

Also, as previously mentioned, the pipe is about £500. even if I never use it that's a small amount to pay for peace of mind.

20 minutes ago, jack said:

That's a very short loop compared to the others. I know you're running this all as one zone, but why not make the WC loop an extension of one of the shorter loops?

 

interesting. hadn't thought of this. will take a look (although not sure how to do it in LoopCAD as I've only been using the standard auto-layout feature!) and see if I can figure it out.

[Thorfun]

21 minutes ago, jack said:

And what about routing around your comms room so that it isn't heated (although if you plan on cooling the slab in summer, it might help there!)

I did think about this but the obvious route is under the stairs and as I'm not sure what the stairs will be or how they'll be fixed to the floor (if at all) I didn't want to take the risk of pipe penetration. there's an MVHR extract in the comms room anyway so that should help to remove most of any heat produced. but I'll definitely see if I can figure something out.

[jack]

5 minutes ago, Thorfun said:

... but I do like to swing a golf club so the plan is to have a net setup so I can practice during the winter etc.

 

Given your username, are you sure it's a golf club?

 

[Bitpipe]

28 minutes ago, jack said:

 

That's a very short loop compared to the others. I know you're running this all as one zone, but why not make the WC loop an extension of one of the shorter loops?

 

And what about routing around your comms room so that it isn't heated (although if you plan on cooling the slab in summer, it might help there!)

 

Re: the gym, I can't imagine working out in a well-insulated house. It's amazing how warm you get even just moving stuff around. I was in our bedroom yesterday installing some shelves and it was borderline unpleasant even though the room was probably only 21 or 22 degrees. I guess you can turn the heating off or down on that loop if needed.

 

I have a gym in basement. Running machine, rower and free weights. Used to use the running machine a lot until I transitioned to outside running.

 

Was like Bikram Yoga but I figured it wouldn't do me any harm  

[Rob99]

On 26/04/2021 at 11:09, Thorfun said:

just spoke to Wunda technical support and their probes have 2 wires and he said they're not proprietary and should work with other systems. they work with the Heatmiser systems that Wunda also supply so I see no reasons why they shouldn't work with Loxone.

 

@Dan F I do notice that the Loxone ones have 3 wires though. do you know what the benefit of that would be? @Rob99? maybe this is something you would know about?

Not been logged on here this week so missed this earlier.

 

The 1-wire probes with 3 wires (confusing that!!) have a separate power line. I'm not a 1-wire technical expert but my understanding is that having a separate power line rather than parasitic power is preferable. Not sure why but likely to be more reliable as doesn't require pull up resistor etc.

 

Loxone's 1-wire extension has the 3 connections so no reason to use sensors with parasitic power.

[Rob99]

On 26/04/2021 at 10:39, Nickfromwales said:

Also, iirc, Wunda don’t do the uber low temp pump and blending set atm. Therefore, if you buy now, I doubt if that kit will cope with the intended application. 
Totally agree; pipes now, cap them off with self-amalgamating tape, not cap ends, and leave for now. 
 

No. Just a few 16mm elbows to daisy chain the loops one to the next, put cold mains on the first pipe, and a pressure gauge on the last one.

I have a Wunda system and the pump set had a manual blending valve whch wasn't particularly good and I found did vibrate and was noisy a lot of the time. Following recommendation from @Nickfromwales I now have an Ivar pump set and blending valve which is fantastic.

 

Leaving the purchase of the manifold and pump set/blending valve until later on is definitely a good thing.

[Rob99]

On 25/04/2021 at 16:24, Bitpipe said:

What you really need is a pipe de-coiler as UFH pipe is impossible to lay without one. Look to borrow or hire one.

I definitely advise one.

 

I laid my first loop without one and it was a nightmare carrying the pipe coil and turning it over and making sure it didn't kink. One 60m loop took me a few hours. Bought a decoiler and similar sized loop took a third of the time and was so easy.

 

I still have the decoiler if you're interested.

[Thorfun]

22 minutes ago, Rob99 said:

Loxone's 1-wire extension has the 3 connections so no reason to use sensors with parasitic power.

5 x 3m 3wire 1-wire temp probes ordered from eBay and delivered ready for installation!

 

10 minutes ago, Rob99 said:

Leaving the purchase of the manifold and pump set/blending valve until later on is definitely a good thing.

thanks. I've told Wunda I only want the pipe for now and they were ok with that.

3 minutes ago, Rob99 said:

I still have the decoiler if you're interested.

thanks Rob but I've already ordered it. I could probably cancel it but it's done now and I'm on to the next thing to organise. 

[Dan F]

38 minutes ago, Thorfun said:

5 x 3m 3wire 1-wire temp probes ordered from eBay and delivered ready for installation

You won't use these for a few months if you use the UFH pipe as conudit. If, for any reason, you are concreting them in then make sure you test them first and potentially install a backup incase of failure.

[Thorfun]

13 minutes ago, Dan F said:

You won't use these for a few months if you use the UFH pipe as conudit. If, for any reason, you are concreting them in then make sure you test them first and potentially install a backup incase of failure.

I am planning on using the conduit. but was going to put them in the conduit before the slab is poured to save doing it later. then I can just fit and forget until I'm ready to wire them up.

[Thorfun]

On 26/04/2021 at 10:39, Nickfromwales said:

Also, iirc, Wunda don’t do the uber low temp pump and blending set atm. Therefore, if you buy now, I doubt if that kit will cope with the intended application. 
Totally agree; pipes now, cap them off with self-amalgamating tape, not cap ends, and leave for now. 
 

No. Just a few 16mm elbows to daisy chain the loops one to the next, put cold mains on the first pipe, and a pressure gauge on the last one.

@Nickfromwales (or anyone else that can answer this!) I know this is an old thread but I am nearly finished with our UFH pipes in the basement and I am going to fill them with water and am looking to buy the 16mm elbows for our 16mm pipe from Wunda. but, am I being stupid, it looks like all the push-fit elbows at Screwfix are for 15mm pipe. like this https://www.screwfix.com/p/jg-speedfit-plastic-push-fit-equal-90-elbow-15mm/97179

 

is this what I want or are there really 16mm elbows that would be more suitable? obviously there are plumbers merchants near me and I could go in and ask but I'm not sure I want to be laughed at while also being sold a left-handed screw driver and a skirting board ladder.

[ProDave]

55 minutes ago, Thorfun said:

@Nickfromwales (or anyone else that can answer this!) I know this is an old thread but I am nearly finished with our UFH pipes in the basement and I am going to fill them with water and am looking to buy the 16mm elbows for our 16mm pipe from Wunda. but, am I being stupid, it looks like all the push-fit elbows at Screwfix are for 15mm pipe. like this https://www.screwfix.com/p/jg-speedfit-plastic-push-fit-equal-90-elbow-15mm/97179

 

is this what I want or are there really 16mm elbows that would be more suitable? obviously there are plumbers merchants near me and I could go in and ask but I'm not sure I want to be laughed at while also being sold a left-handed screw driver and a skirting board ladder.

Just how many elbows do you want and for where?

[Thorfun]

1 minute ago, ProDave said:

Just how many elbows do you want and for where?

I want to fill all the loops with water. so I was thinking of hose pipe in to the first pipe and then elbow to elbow across all the other pipes with a pressure gauge on the last pipe. I have 7 loops so that would be 12 elbows. once the screed has been poured and gone off they can be removed and the ufh pipes eventually fitted to a manifold.

[Nickfromwales]

1 hour ago, Thorfun said:

I want to fill all the loops with water. so I was thinking of hose pipe in to the first pipe and then elbow to elbow across all the other pipes with a pressure gauge on the last pipe. I have 7 loops so that would be 12 elbows. once the screed has been poured and gone off they can be removed and the ufh pipes eventually fitted to a manifold.

JTM sell them too

 

Carry on as you are, and this is what I did when I wanted to fill and test at slab level. I didn’t want to fit the manifold in that instance as I feared it getting damaged. 
If you think you can mitigate then buy the manifold now and fit it, saving the loss of the cost of the fittings   

[Thorfun]

2 hours ago, Nickfromwales said:

JTM sell them too

 

Carry on as you are, and this is what I did when I wanted to fill and test at slab level. I didn’t want to fit the manifold in that instance as I feared it getting damaged. 
If you think you can mitigate then buy the manifold now and fit it, saving the loss of the cost of the fittings   

Ahh….so 16mm fittings do exist! I’ll try my local plumbers merchants next week. 
 

im not ready for the manifold yet and I’m happy to take the hit on the fittings. Self-building is stressful enough without trying to rush too many things before you’re ready. I’m learning that a more “que sera sera” attitude is healthier but does lead to a slower build!

[Nickfromwales]

12 minutes ago, Thorfun said:

Ahh….so 16mm fittings do exist! I’ll try my local plumbers merchants next week. 
 

im not ready for the manifold yet and I’m happy to take the hit on the fittings. Self-building is stressful enough without trying to rush too many things before you’re ready. I’m learning that a more “que sera sera” attitude is healthier but does lead to a slower build!

Less stressed is best   

[Thorfun]

10 hours ago, Nickfromwales said:

Less stressed is best   

yep.

 

13 hours ago, Nickfromwales said:

JTM sell them too

interestingly those 16mm fittings from JTM are bespoke:

 

"JTM 16mm compression fittings manufacturer to BS & EU standard, The fittings is made up by hand of a 15mm compression fitting and a 16mm nut and insert. "

 

So, are 15mm push-fit also suitable for this task?

 

I'm confused as there don't seem to be a lot of 'native' 16mm elbows/fittings. I did find these (https://underfloorparts.co.uk/product/16-x-16mm-x-1-pr-elbow-pexal-multilayer-pipe-upel16m/) but they're stupidly expensive!

[Rob99]

Some less expensive options..........

 

https://plumbing-gear.com/5-x-hepworth-hep2o-16mm-tees-hep20-plastic-pushfit-push-fit-tee-underfloor-762-p.asp

 

https://theunderfloorheatingsite.co.uk/shop/water-under-floor-heating/accessories/couplings/pack-of-6-16mm-x-16mm-elbow-double-coupling-pex-al-pex-brass-compression-fitting/?gclid=Cj0KCQiAgP6PBhDmARIsAPWMq6l8SF7z1lNmqctzvq5c20vrEDCbmUguM0fQy1oov6w8hp1jv42Kj9saAr9eEALw_wcB

 

https://www.screwfix.com/p/jg-speedfit-plastic-push-fit-equal-90-elbows-15mm-10-pack/57953

These say 15mm but the JG website specifies them as 16mm

 

I'll try and find a spare bit of my UFH Pex pipe and see if it fits in the JG fitting.

[Thorfun]

1 hour ago, Rob99 said:

Some less expensive options..........

 

https://plumbing-gear.com/5-x-hepworth-hep2o-16mm-tees-hep20-plastic-pushfit-push-fit-tee-underfloor-762-p.asp

 

https://theunderfloorheatingsite.co.uk/shop/water-under-floor-heating/accessories/couplings/pack-of-6-16mm-x-16mm-elbow-double-coupling-pex-al-pex-brass-compression-fitting/?gclid=Cj0KCQiAgP6PBhDmARIsAPWMq6l8SF7z1lNmqctzvq5c20vrEDCbmUguM0fQy1oov6w8hp1jv42Kj9saAr9eEALw_wcB

 

thanks Rob. I think my Google search skills are a bit off at the moment! 

 

1 hour ago, Rob99 said:

https://www.screwfix.com/p/jg-speedfit-plastic-push-fit-equal-90-elbows-15mm-10-pack/57953

These say 15mm but the JG website specifies them as 16mm

 

I'll try and find a spare bit of my UFH Pex pipe and see if it fits in the JG fitting.

in that case I think these are the ones I'll use. it would be great if you could find some ufh pipe and see if they fit. if not, I might just buy them and return them if they don't fit! ?

[Rob99]

1 hour ago, Thorfun said:

2 hours ago, Rob99 said:

I'll try and find a spare bit of my UFH Pex pipe and see if it fits in the JG fitting.

in that case I think these are the ones I'll use. it would be great if you could find some ufh pipe and see if they fit.

No luck on the UFH pipe I'm afraid ☹️   

Looked everywhere I can think of but don't seem to have kept any (very unusual for me!!) possibly as I only had small offcuts and couldn't see any use for them. 

Found loads of spare bits of the JG 15mm pipe but that's no help.

 

[Adrian Walker]

The UFH pipes need to be  less than 100mm down  to work effectively.

[PeterW]

JG definitely don’t fit 16mm PEX

[Thorfun]

23 minutes ago, PeterW said:

JG definitely don’t fit 16mm PEX

that's a shame. thanks for letting me know.