ASHP + UFH quote

[joe90]

44 minutes ago, joth said:

but FWIW in case this is of help: I'm in the same camp of wanting someone to own specifying and supplying and installing the whole system, to meet my requirement spec, as my limited time is better invested elsewhere on the project.

 

Yes I understand this, I designed and installed my own systems and because of my limited knowledge it took a long time to get it right, and I am retired and on site 24/7.

[Pocster]

Does sound on the top side price wise.

i have similar floor area and including install ( no vat of course ) around 13k that’s all ufh and ASHP , tanks etc .

 

Down here I used 

http://www.wdsgreenenergy.co.uk/

 

As recommended on here ! They’ve been very patient with me ..... ?

 

 

Edited May 23, 2019 by pocster

[Ferdinand]

Buildhub - the site that creates homework. ?

[Redoctober]

@ProDave To you it may well seem expensive. To us it was value for money, given the net cost as you say will be £7600!!  I posted these details in an attempt to provide some guidance rather than to generate a debate as to whether or not we paid too much for the system. As @joth said above, there will always be a discussion about price so perhaps it is sometimes better to just provide figures as opposed to judgments. Just a thought that's all.

[newhome]

As someone who doesn’t have enough insulation in the floor here it’s still an area of massive regret and not one I can now fix so I would definitely take the advice above and see if you can incorporate more insulation, and definitely see if you can get a quote for the whole ASHP supply and install as that should just make life so much easier for you in terms of ongoing support. The minute that chain is broken somewhere it starts to get tricky. It may cost a bit more than people here think is necessary but I think it will be worth it. 

[Jenni]

wow, so many replied so quickly, thank you everyone. 

 

@newhome 

yes aiming for RHI, I know this is an expensive way of getting a result, but some money back over the following years isn’t to be sniffed at.

Sorry, when I say “organise professional to do the install”, I should clarify that this will be someone off NuHeats list, so that, as you say, I have continuity of cover / reduced chance of blame game.

Yes, VAT is reclaimable.

 

@Ferdinand

Good point about the payment structure. I’ll talk to them about possible staging / retainer. Also about using credit card, if only for a portion. I have another entire quote from another company, but their refusal to accept credit cards (along with some other issues) are persuading me away from them.

 

@ProDave

Just the 2 tanks, a 300l with a 100l buffer.

It’s clear that I need to involve an installer before progressing the order, I’ll get onto that, thank you.

 

@Alexphd1

It suits me to have 2 manifolds, the floor is actually split level (300mm difference), and being long and narrow, one manifold will be sited near the tank, the other will be about 10m away, supplied by a well-insulated feed.

As to the number on each. One will be supplying 4 zones. The other 5 zones. I assumed some zones would be having multiple loops, but I’ll check with Nuheat, thanks.

 

@PeterW

Yes, MCS install for RHI. I know it’s paying through the nose compared to DIY, but I think there’s a value in that.

I’ll quiz NuHeat about the 1 pump running 2 manifolds issue.

 

@JSHarris

I’ll be honest, the numbers all go over my head a bit, but I understand the fundamentals of what you’re saying, thank you, and the bottom line being wasted heat and hence higher running costs. As I said, I don’t have full control of the project, so I am where I am to go forward from.

 

@le-cerveau

Is there a problem with dial thermostats?

I know the components could be sourced cheaper, but I’m after an all-in solution that I don’t have to worry that at the end it doesn’t work well due to my inability to match parts etc.

I was also surprised that the tank is only ‘C’, I’ll ask Nuheat about that as it does seem odd to me.

 

@joth

Thanks, I have a full time job and trying to partially maintain a busy hobby, while also doing my best on this build, so at times cash has to be spent rather than time.

 

@Redoctober

Thank you for your figures, interesting to see. Did you start with a supply company, or start with the installer?

 

@pocster

Thank you for the link, it can’t hurt for me to get another quote (except it could aid & abet my decision paralysis!)

 

 

Edited May 23, 2019 by Jenni

[dpmiller]

7 hours ago, Jenni said:

As I said, I don’t have full control of the project

 

 

so who does?

[Nickfromwales]

On 23/05/2019 at 23:46, Jenni said:

It suits me to have 2 manifolds, the floor is actually split level (300mm difference), and being long and narrow, one manifold will be sited near the tank, the other will be about 10m away, supplied by a well-insulated feed.

As to the number on each. One will be supplying 4 zones. The other 5 zones. I assumed some zones would be having multiple loops, but I’ll check with Nuheat, thanks.

Morning!

9 ports on a single manifold will work perfectly well and significantly reduce costs and complexity. This cannot be practised in an install where a lot of the loops will then exceed 100m in length, but if it means one or two are at, or slightly above 100m, you'd be fine. I have done loops in far worse places ( insulation wise ) and had loops of 130m in one zone, and it worked VERY well. The designer / supplier will of course cover their arse and insist on the dual manifold if even one loop creeps over this tipping point, as that'll need to be adhered to in order to offer a warranty.

On 23/05/2019 at 23:46, Jenni said:

Is there a problem with dial thermostats?

 

Yes 100%. They are disgustingly inaccurate in conjunction with UFH. DO NOT fit them at any cost. They work well with radiators which are able to make speedy changes to the air temp, but UFH is a long and low output into a very energy dense emitter, so you'll have a stat that misses the room getting to temp ( and then you'll have a big overshoot ), and then it'll miss the room cooling back down ( and then you'll have an even bigger undershoot ). The hysteresis of the heating will be governed by the response times of the stats, so choose those very well. You want a stat with a minimum of 0.5^oC  hysteresis 0.2 would be better. 

Why do you seem wedded to NuHeat? Wunda are very good, do free designs after you commit to a purchase, offer good support and I've fitted a mountain of their gear to date without issue. A good few here have used them too. Shop around, buy the kit yourself, but under the beady eye of the designer + supplier. Then it's no more difficult for an installer to fit than any other system as the thought has been removed entirely and the system will be sold as being fit for purpose.  

[Jenni]

On 24/05/2019 at 07:18, dpmiller said:

 

 

so who does?

 

It's an interesting family combo, myself, 2 brothers and mother.

[Jenni]

thank you @Nickfromwales, I had thought the difference in thermostats was really just aesthetic, with added functionality on the more expensive ones, rather than accuracy issues.

 

I get what you're saying about the manifold, and if the floor was a single layer I wouldn't hesitate to just have 1, but with the split level (300mm) I'm not sure how the pipes would be laid over the height change?

 

I'm not necessarily wedded to Nuheat, but I did want to go with a 'package' supplier, as I'm not confident to get it right otherwise, and am prepared to pay the extra for that peace of mind. 

Edited June 3, 2019 by Jenni

[Nickfromwales]

40 minutes ago, Jenni said:

thank you @Nickfromwales, I had thought the difference in thermostats was really just aesthetic, with added functionality on the more expensive ones, rather than accuracy issues.

 

I get what you're saying about the manifold, and if the floor was a single layer I wouldn't hesitate to just have 1, but with the split level (300mm) I'm not sure how the pipes would be laid over the height change?

 

I'm not necessarily wedded to Nuheat, but I did want to go with a 'package' supplier, as I'm not confident to get it right otherwise, and am prepared to pay the extra for that peace of mind. 

The UFH pipes can simply rise to the upper manifold location, from the lower floor section, therefore allowing air to be vented at the highest point ( the vent on the manifold ). You couldn't have the manifold on the lower section and pipe uphill from it for eg as the air ( accumulative gasses ) would be trapped there. Absolutely no reason not to go for the single manifold TBH, just need an inventive and competent plumber / installer to get stuck in. 

Go with whichever package / provider you feel comfortable with, but explain what you want, make clear your expectations, and come back here to sense check anything that your told and maybe didn't fully understand.

[Jenni]

So, is it possible for the UFH pipes to be in lower floor level, turn 90' to come out the top, up a retaining wall 300mm, then turn another 90' into the higher floor level? And how would that work with the 2 floor levels being poured on the same day? 

[Nickfromwales]

4 minutes ago, Jenni said:

So, is it possible for the UFH pipes to be in lower floor level, turn 90' to come out the top, up a retaining wall 300mm, then turn another 90' into the higher floor level? And how would that work with the 2 floor levels being poured on the same day? 

Yes, that would be fine. The pipe runs from the lower to the upper would ideally need insulation on them where they no longer service the area they are meant for, so a dedicated pipe way would be necessary to accommodate the 16mm pipe, plus a 9mm wall insulation, so 34mm total diameter per run.

Each pipe run, when turning 90^o backto horizontal at the upper slab level, would need to be in the lowest part of the screed ideally, so as not to interfere with the upper pipe runs. You just get everything done in anticipation of the pour, like sealing up pipe ways with expanding foam / insulation / sand cement patching mix or whatever it takes to keep the upper pour exactly where it is meant to stay.

If it means one manifold and it just requires a bit of tenacity, I think it's worth striving to achieve.

 

[Jenni]

Thank you very much Nick, I'll pursue that as an option.

[Nickfromwales]

It'll require some effort, but is perfectly do-able  

[Jenni]

I've spoken to our structural engineer this afternoon, to ascertain why the slab is spec'd to be 150mm and the consequences of reducing the thickness (so as to increase insulation depth). 

 

His view is that, as the concrete is the final floor finish (ie, polished), and the thinner the slab, the more likely it is to crack, that 100mm would be fine, but 125mm would be the least he'd go to.

 

So risk calculation. Thinner = more likely to have unsightly cracks vs improved insulation (up from 70mm Celotex to 95mm).

 

Are there any other tyres of insulation that give better values for the same depth as 70mm Celotex? 

Edited June 4, 2019 by Jenni

[Mr Punter]

I am a bit late to this thread. Is it possible to excavate a little more to get an acceptable level of insulation AND a floor slab that won't crack?

[Jeremy Harris]

If the slab is reinforced then it's extremely unlikely to crack.  Our slab is 100mm, with steel reinforcement and UFH pipes embedded in it, which is sat on 300mm of EPS insulation. 

 

PIR foam is about the best (affordable) insulation you can get, I'm afraid.  The only stuff that outperforms it is either vacuum insulated panels or aerogel, but both are expensive and I'm not sure they are OK for under slab use.

[Jenni]

Nope, not possible at this stage @Mr Punter.

 

Thank you @JSHarris.

Is your slab polished concrete finish?

What height is your reinforcement within the slab? (iirc your pipes are attached to top of reinforcing?) 

 

We have some slab thickenings for loadbaring walls, where we'll be be putting 2 layers of mesh, currently spec'd at 50mm and 100mm, within 150mm slab. The rest of the slab just 1 layer of mesh at 100mm.

[Jenni]

Just thought, I have a 100mm reinforced slab in my shed (9mx7m, divided into 3 with expansion joints), and one of those has cracked really badly, and it's not even the bay I park the car on.

But, it probably wasn't the best laid concrete ever, should that colour my view. ? 

[Jeremy Harris]

Our slab isn't polished, but was power floated to form the finished floor to which we laid travertine stone and bamboo.  We have a pretty large area of 12mm thick travertine, so if there had been any movement in the slab it would have cracked the stone for sure.

 

The steel reinforcement is in the centre of the slab, with the UFH pipes cable tied to it.  The slab is thickened around the edge to 200mm, and the same across the area where two load bearing internal walls sit:

 

 

 

[Danny68]

Has anyone polished a a floor that has fiberglass strands in it, if it polishes up OK then you could reduce to 100mm thickness 

[PeterW]

1 minute ago, Danny68 said:

Has anyone polished a a floor that has fiberglass strands in it, if it polishes up OK then you could reduce to 100mm thickness 

 

Its difficult to do as it doesn’t polish well due to the strands. Better to scour off and then resin

[Pocster]

2 hours ago, JSHarris said:

If the slab is reinforced then it's extremely unlikely to crack.  Our slab is 100mm, with steel reinforcement and UFH pipes embedded in it, which is sat on 300mm of EPS insulation. 

 

PIR foam is about the best (affordable) insulation you can get, I'm afraid.  The only stuff that outperforms it is either vacuum insulated panels or aerogel, but both are expensive and I'm not sure they are OK for under slab use.

We had vac insulation 

Had to put T&g cement board ontop 

Reinforced concrete poured on that .

But as @JSHarris says - expensive!!! Around £100 a square metre ......... ?

Edited June 4, 2019 by pocster

[Jenni]

3 hours ago, pocster said:

We had vac insulation 

Had to put T&g cement board ontop 

Reinforced concrete poured on that .

But as @JSHarris says - expensive!!! Around £100 a square metre ......... ?

 

Ouch!