Upstairs - UFH, AC or Fan coils?

[SBMS]

Planning our upstairs heating for our build. Downstairs is wet UFH, ASHP. We’ve got a first and second floor (attic rooms).  Some

small risk from overheating due to a fair bit of glazing so would like some active cooling upstairs. 
 

Trying to decide what to put upstairs.
 

UFH upstairs on two floors is coming out expensive. Mainly

labour costs (we are not going to fit it ourselves). Seems that it’s overkill if heat requirement is low? And we can’t cool. 
 

I thought about putting split AC units in each of the 5 bedrooms and using them for heat as well. But not sure about having to remember to turn them on if it gets nippy, fans running etc? But cooling would be fine. 

 

I therefore thought about a ducted AC system upstairs (maybe a couple of zones) that could do heat and cooling?

 

Other option is fan coils. I don’t quite understand the condensation risk - does all pipe work need to be lagged? Do I need condensate drain off at each unit? Are they as effective at cooling as an AC system?

 

Would appreciate peoples throughts:

Upstairs options

option 1 - UFH + split AC

option 2 - radiators + split AC

option 3 - split AC (heat and cool)

option 4 - ducted AC (heat and cool)

option 5 - fan coil units (heat and cool)

Edited November 23 by SBMS

[nod]

I would really look at your insulation levels 

We have built a traditional brick and block UFH on the GF 

We never used the radiators in five year 

HP and GF UFH this time and we are finding exactly the same The first floor temps pretty much mirror the GF temps Within 1 C

Surely the whole point of Self build is to exceed what is available Upgrading your insulation is always money well spent 

[SBMS]

9 minutes ago, nod said:

I would really look at your insulation levels 

We have built a traditional brick and block UFH on the GF 

We never used the radiators in five year 

HP and GF UFH this time and we are finding exactly the same The first floor temps pretty much mirror the GF temps Within 1 C

Surely the whole point of Self build is to exceed what is available Upgrading your insulation is always money well spent 

Nod - agreed and we are pretty well insulated to be honest. 200mm cavity, blown beads etc. I know your last build you put radiators and never used them but I can’t bring myself to put no heating upstairs. Cold wife and cold children. 

[joe90]

4 minutes ago, SBMS said:

but I can’t bring myself to put no heating upstairs.

I put no heating upstairs but enough sockets in places to run oil radiators or heaters for the odd day or week they might be required. I could not even see the need for wired spurs for heaters as a 13 amp socket is sufficient. How many days a year would heating be required upstairs?

[ProDave]

I am another who put electric points for bedroom panel heaters and have never used them.

 

But @SBMS mentions upper floors, so is this a THREE storey house?

 

If you wanted to fut UFH just in case, the parts are very cheap, why not DIY?

[SBMS]

12 minutes ago, joe90 said:

I put no heating upstairs but enough sockets in places to run oil radiators or heaters for the odd day or week they might be required. I could not even see the need for wired spurs for heaters as a 13 amp socket is sufficient. How many days a year would heating be required upstairs?

@joe90 I'm not sure - the thing I'm trying to work out is the following... So on Jeremy's heat loss calculator, plumbing everything in its looking like a worst case -9 outside and 20 inside, its around:

 

Total heat loss =

5885

W

 

So if I didn't want any radiators upstairs, I would need to ensure that my UFH provided, in this worst case scenario, about 5.8kW (call it 6) output.  Is that correct logic? Presumably if my house was a box with nothing on the floors like kitchen units, islands etc, and all heat rose vertically this would work.  But my house isn't shaped like that, it's like this:

 

I think this means that the 134m2 double story part, once I take away the unuseable floorspace (staircases, kitchen units etc) there's about 107m2 of UFH space providing the space heating requirements for approximately 134 m2 (ground floor bit), 117m2 (first floor) and 88m2 (attic rooms):

 

Total power req (kW)	6	475	total sqm
	SQM	UFH Power Delivery SQM	kW Required
Single Storey 1	44	44	0.56	kW
Single Storey 2	92	92	1.16	kW
Ground Floor	134	339	4.28	kW delivered in 107m2
First Floor	117	0	0
Second Floor	88	0	0

 

I suppose the question is - can 107m2 comfortably provide 4.28kW of heating output, and/or would it be preferable to have a lower output UFH with some upstairs radiators/fan coils upstairs (that can also provide cooling). What would be the disadvantage to this (bearing in mind we do want some cooling in the bedrooms as well)?

[SBMS]

4 minutes ago, ProDave said:

I am another who put electric points for bedroom panel heaters and have never used them.

 

But @SBMS mentions upper floors, so is this a THREE storey house?

 

If you wanted to fut UFH just in case, the parts are very cheap, why not DIY?

@ProDave correct - its rooms in the attic so technically 3 floors.  I could do UFH upstairs (would rather not fit myself as I simply don't have the time for that - will be doing as much as I can such as MVHR but need to be realistic).. but it doesn't provide any cooling hence looking at either ducted AC/split AC or fan coils?

 

House section for context:

 

Edited November 23 by SBMS

[nod]

33 minutes ago, SBMS said:

Nod - agreed and we are pretty well insulated to be honest. 200mm cavity, blown beads etc. I know your last build you put radiators and never used them but I can’t bring myself to put no heating upstairs. Cold wife and cold children. 

I agree I would definitely put Rads in the bedrooms and bathrooms 

We did that previously and against my wife’s wishes have installed stainless Rads But we will never use them 

BUT we would of had difficulty selling our previous house without the option 

I definitely wouldn’t go to the trouble and expense of UFH in bedrooms though UFH isn’t great with carpets Definitely not thick wool carpets that we like 

[ProDave]

What is your location?  Over heating is not an issue for us and in many cases it is a result of too much glazing.

 

Rather than separate A2A AC units, you can run Fan Coil units from your ASHP and they can work for cooling as well as heating.

[SBMS]

3 minutes ago, ProDave said:

What is your location?  Over heating is not an issue for us and in many cases it is a result of too much glazing.

 

Rather than separate A2A AC units, you can run Fan Coil units from your ASHP and they can work for cooling as well as heating.

North West - Lancashire.  SAP guys have said there's a small risk of overheating in some of the bedrooms as we are using a 0.6Ug triple glazed pane (they've said a 0.4Ug would solve this but that's very expensive).  I am definitely erring on the side of fan coil units - if they don't need to provide heat then it's just the capital install cost, but at least they are there for cooling if needed (they say it'll only get hotter).  I don't know how familiar installers are with fan coil units though...  The one part of the house I'm not DIYing is the plumbing (I hate it, and always get it wrong  )

[SBMS]

13 minutes ago, nod said:

I agree I would definitely put Rads in the bedrooms and bathrooms 

We did that previously and against my wife’s wishes have installed stainless Rads But we will never use them 

BUT we would of had difficulty selling our previous house without the option 

I definitely wouldn’t go to the trouble and expense of UFH in bedrooms though UFH isn’t great with carpets Definitely not thick wool carpets that we like 

This is actually a great point.  All our rooms upstairs except wet rooms will be carpeted and with thick wool as my wife likes that... I think that knocks UFH out (although might price up wet UFH in the bathrooms). 

 

 

Would you consider an AC system (split or ducted) upstairs - or fan coils, or just standard rads and hope it doesn't overheat?

 

[joe90]

It has to be said also that selling a house with no upstairs heating might be more tricky (even if it’s not used!!!)

[crispy_wafer]

Upstairs we have split ducted air to air in the bedrooms, bathrooms we have electric ufh, and I’m considering putting a fan coil rad in the bathrooms as a last minute decision instead of electric towel rads before I finish boarding the ceilings.  It’ll cost nothing to pipe up, as I’ve got loads of 16mm pipe left from the ufh.

[SBMS]

53 minutes ago, crispy_wafer said:

Upstairs we have split ducted air to air in the bedrooms, bathrooms we have electric ufh, and I’m considering putting a fan coil rad in the bathrooms as a last minute decision instead of electric towel rads before I finish boarding the ceilings.  It’ll cost nothing to pipe up, as I’ve got loads of 16mm pipe left from the ufh.

Interesting. What made you go split ducted air instead of fan coils?

[scottishjohn]

3 hours ago, SBMS said:

All our rooms upstairs except wet rooms will be carpeted and with thick wool as my wife likes that..

when ifiited my UFH in present house  I relaid the expense acminster and underlay  as it was too good  to dump

 I did replace with a tiled floor a few years later and it just worked quicker for a temp change 

It worked but not as quick as hard floors

 

so do not discount UFH in bedrooms 

 all it will mean is that the temp drop on ufh will be less,so it won,t cost anymore in power , just takes longer to get there  as it will not allow as much heat out as quick  as a hard floor 

but it will work 

 

 my upstairs UFh  is insulated foil coated boards with pipe cut outs . covered with 20mm T+G cement board to spread the heat 

total thickness is about 40mm

 my crappy architect wanted use sand mix  infill on joists ,which meant fitting bottom plwood beteen eaxh joist -- seemed too much weight and a messy job 

Edited November 23 by scottishjohn

[crispy_wafer]

1 hour ago, SBMS said:

Interesting. What made you go split ducted air instead of fan coils?

When I started, fan coils and ashp cooling wasn’t a much travelled path in the trade, and those who I was taking advice from admitted it was doable but wouldn’t warrantee any work if we had issues with condensation drips and damp…. We had a2a at work and use it for both heat and cool, so just went with that, looking back I’ve spent twice, and should have insisted…. Upstairs I reckon will be cooling the majority of the time, we like bedrooms at 17/18 degrees and I reckon heat wise that will be achieved from air movement from downstairs.  
 

My biggest concern is bathrooms, although I put in electrics for a mat and towel rad in each I’m now thinking I could whack a fan coil rad in there and make use of the ashp at this time of the year, the extra load won’t be much as it will be on the ufh circuit. I may just run the pipe work and leave in the floor void.  So if it becomes an issue later on then tails can be pressed on, and pulled through the floor.

 

[SBMS]

56 minutes ago, crispy_wafer said:

looking back I’ve spent twice, and should have insisted

Should have insisted on using fancoils you mean instead of ducted A2A? You wouldn't recommend A2A then?

[crispy_wafer]

haha, ive no idea, i'm still grafting away trying to build the place - plasterboarding now...  Either way I'm sorted for heating and cooling, I've got ducted ac downstairs too, and with the amount of south facing glass it will certainly come in useful, upstairs and down.  The main thing really is we have heating and cooling and will be comfortable. 

[SBMS]

55 minutes ago, crispy_wafer said:

haha, ive no idea, i'm still grafting away trying to build the place - plasterboarding now...  Either way I'm sorted for heating and cooling, I've got ducted ac downstairs too, and with the amount of south facing glass it will certainly come in useful, upstairs and down.  The main thing really is we have heating and cooling and will be comfortable. 

Fair enough!! Do you mind me asking what was the cost for your A2A ducted? Is it zoned?

[crispy_wafer]

No probs, 7600 ish for a 10kw multi split, 4 individual units in loft and cupboard spaces, with ducting to bedrooms and downstairs kitchen diner.  Mitsubishi heavy industries, whilst not the greatest, certainly not the worst out there, plenty of installers out there who are familiar of it needs fettling in the future. I think the price was about fair.  Has to be said though, a single multi like this will only do heat or cool at once.  If you ever envisage heating and cooling at same time then it needs separate units.