UFH - connect to rads from manifold? Boiler now, ASHP in future?

[oranjeboom]

Hi, 

Following on from advice received in the other 'world' (ebuild) I now have my final design for floor buildup in my renovation of a 1950s bungalow:

15mm Finished floor

100mm reinforced concrete with UFH (ie meshed)

275mm EPS70

DPM

Sand blinding

100mm compacted hardcore 'type 1 MOT'

Existing in-situ compacted ground

 

 

Currently digging up 18t of hardcore and 30t of soil so that  get the necessary depth. I've seen sense to get some contractors in for that part though. Back and knees are tired from all my toiling. But the rest I pan to do (i.e. insulation, UFH laying, concreting will be left for someone else as it needs to be level and power floated).

Having spent many hours reading up on ebuild I still have some questions remaining:

1) House has PV panels and the original idea was to have an ASHP. Originally house had oil which I have stripped out. I did lay in gas pipeline for kitchen (wife only does gas...) but due to escalating costs for piled foundations for the extensions I will now fit a combi boiler. Perhaps one day when it makes economic sense will I change to ASHP. I presume that will be a fairly easy swap-over?

2) I'll have a utility and small bathroom where I will probably extend the loops from hallway into. But then also had a rad in each room also. Should I connect the rads to the UFH manifold or direct to the boiler feed? I presume the latter? Or should I have electric towel rads instead? Running costs/efficiency is my main concern. I can route plumbing to boiler feed up through the wall and into loft without too much aggro.

3) In a similar vein, I have a 2 storey extension (175mm sips) and am wondering whether to have UFH or to go for rads instead on 1st floor. The only reason I am thinking of UFH upstairs is because I wanted to add some acoustic boarding on the floor and one supplier is able to do that with a 2-1 ufh/acoustic board product, but seems costly at nearly 2k (34sqm, 150mm centres). This is the same cost as my ground floor UFH quotes which is 135sqm! So probably a better solution to get separate acoustic boards and then fit rads. So I presume I would connect the rads direct to the boiler feed rather than the UFH manifold that would be heating the downstairs pipework?

Comments/suggestions welcome!

 

OB

[Nickfromwales]

Am I reading this correctly, as in you'll have UFH AND rads ?

[Onoff]

6 minutes ago, Nickfromwales said:

.....as in you'll have UFH AND rads ?

As will I to start off with. Renovate downstairs room at a time and switch to UFH.

[oranjeboom]

Hi Nick, I thought you may contribute here!

6 minutes ago, Nickfromwales said:

Am I reading this correctly, as in you'll have UFH AND rads ?

Well possibly. But only upstairs with TRVs. My SIPs extension won't be as ' thermally sound' as other builds on here, so I'm not convinced the 'no UFH upstairs' will work. Or should I be brave? That's why I was thinking of rads upstairs as a minimum.

[oranjeboom]

3 minutes ago, Onoff said:

As will I to start off with. Renovate downstairs room at a time and switch to UFH.

My introductory spiel is always a bit long and the detail sometimes gets lost. I've been meaning to add a blog on ebuild (good thing I didn't) but will start one here as soon as i get the permissions. Bungalow is completely gutted, so all rooms have nothing in them apart from the walls, ceilings and a large 500mm hole in them. Ready for me to plant the potatoes in now.

All rads were crap, full of gunge, pipework surface-mounted...yuk....now all rusting outside whilst I wait for the price of scrap metal to go up again!

 

[Nickfromwales]

Ok, so no areas will end up being Ufh heated as well as rads in the same space? That was my question . 

Rads upstairs is a good fail safe as others here with full MBC passive builds have reported back on a need for a little trace heating. Have you considered Ufh up and down as it would be mono temp then as opposed to two differing disciplines / controls / components etc?

[oranjeboom]

26 minutes ago, Nickfromwales said:

Ok, so no areas will end up being Ufh heated as well as rads in the same space? That was my question . 

Rads upstairs is a good fail safe as others here with full MBC passive builds have reported back on a need for a little trace heating. Have you considered Ufh up and down as it would be mono temp then as opposed to two differing disciplines / controls / components etc?

I won't have UFH and rads in the same space. I'm hoping the renovation is a bit better than that!!

Fail safe would be the best approach. I can here the wife whingeing already about the coldness upstairs...Though, having lived in the static for 2 yrs, I hope she has become a bit more accustomed to 'cooler' temps!

I did consider UFH upstairs but I need to lay down some acoustic boards up there anyway. Wunda do a combination product for this (http://www.wundafloorheating.co.uk/downloads/F09 Acoustic Fibre Overfloor Panels.pdf) but this seems ££££ for what it is. I didn't want to go for separate acoustic boards plus a separate UFH boarding system on top of that. I have threshold issues with the balcony door then also. So that's why I was thinking of connecting rads with TRVs to the boiler as an easier solution. I'm hoping they won't be needed a lot but be there in case the boss thinks it's too cold.

FYI: bungalow will have 275mm EPS in floor, 3G windows, maximum loft insulation, 100mm EWI, so hoping heat loss is minimal. The two storey SIP extension will have 250mm EPS plus 50mm PIR so hoping for even less heat loss. Rising heat from here will hopefully be sufficient to travel upstairs to keep that warm enough not to warrant having the rads kick in.

Edited June 8, 2016 by oranjeboom
Linky added

[Nickfromwales]

Can you hang the ceiling downstairs on acoustic rail / fixings and use dense acoustic wool in between? That would leave you free reign upstairs. Just spreader plates then. 

Another option could be acoustic wool and then spreader plates, 22mm weyroc, 6mm dense rubber acoustic mat then your choice of floor covering. With the spreader plates the heat will still get through imho. 

[oranjeboom]

Thanks Nick. yes, part of the plan was already to use acoustic wool in the ceiling. I wasn't going to go for resilient bars, but perhaps they will do the job. I already have 22mm egger board as the flooring and I read that acoustically it would be better to add either a thicker or thinner layer to the existing one. I will get a further quote for spreader plates then to see how that compares.

But I was still thinking have a couple of rads upstairs may work. It's actually only 2 rooms upstairs (bedroom / landing / bathroom) approx 35sqm.