UFH upstairs - alternatives?

[joe90]

Cool, does this not mean that if you want to override the timings you have to go to the CU ? I installed electric UFH fir a customer that had a programmer with everyday settings but an override button that allowed an instant 1hour "on now" facility which is what I fancy. I can't remember the make. 

[PeterW]

21 minutes ago, joe90 said:

Cool, does this not mean that if you want to override the timings you have to go to the CU ? I installed electric UFH fir a customer that had a programmer with everyday settings but an override button that allowed an instant 1hour "on now" facility which is what I fancy. I can't remember the make. 

 

Yes but tbh they are planned to be coming on an hour in the morning and one in the evening. Boost will be via button on the CU but it's accessible anyway. 

[Barney12]

1 hour ago, PeterW said:

So I've got an 18 way consumer unit that will have in it all of the time switches and thermostats for :

 

- eUFH / TRail bathroom

- eUFH / TRail ensuite

- Immersion timer

- wUFH pump timer

- wUFH temp controller 

 

Means that on the wall outside the bathroom there is just an isolator for the towel rail and a simple thermostat for the floor. 

 

Towel rail elements are 300w PTC so self regulating, floors are either 200w or 500w so total load is 1.3kw in total. 

 

 

 

 

@PeterW Do you have any details of the CU mounted time switches and thermostats you intend to use.

I hate too much wall clutter

[PeterW]

21 minutes ago, Barney12 said:

 

@PeterW Do you have any details of the CU mounted time switches and thermostats you intend to use.

I hate too much wall clutter

 

Using these generic ones from ebay

 

[Jeremy Harris]

I have a couple of those ebay ones, one controlling my car charge point and one as part of the water filtration system.  They work well, and fit neatly into a standard CU.  Good value too, but I've no idea how reliable they may be in the longer term, as ours have only been in for around a year.  Seem to keep time well enough though.

[PeterW]

I figure if I'm only switching 1-2a they will last longer ..!

[Jeremy Harris]

12 minutes ago, PeterW said:

I figure if I'm only switching 1-2a they will last longer ..!

 

Mine only switch a few mA, but one can carry around 15A for a few hours, the car charging point one.  It's usually switching high current that does the contacts in, and in my case the actual switching in both cases is done by a DP contactor, rated at 40A.  In the case of car charge point, even then the contactor doesn't switch much current, as the car controls the switching internally, based on the J1772 signalling protocol.  The only time the contactor would operate under load would be if there was a fault.

 

I bought a couple of spare timers, anyway, as I reckoned that at that price is wasn't going to break the bank to hold spares!

Edited February 8, 2017 by JSHarris

[joe90]

5 hours ago, PeterW said:

 

Yes but tbh they are planned to be coming on an hour in the morning and one in the evening. Boost will be via button on the CU but it's accessible anyway. 

Fair enough, but my CU will be nowhere near my bathrooms and her indoors will be sending me downstairs and over to the plant room to put the heating on for her, I prefer it to be just outside the bathrooms so she can do it herself!! .

 

are the programmers not built for a  bathroom envoironment ?

[Jeremy Harris]

13 minutes ago, joe90 said:

are the programmers not built for a  bathroom envoironment ?

 

Generally not, or at least, all the ones I looked at when I fitted electric UFH to our old bathroom weren't.  It may well be that there are sealed, or SELV, versions around now, though. 

 

I just took the easier root of fitting the controller/programmer on the wall in the hall, right outside the bathroom door, to avoid any doubt, but having said that, the rules have relaxed slightly on bathroom zones since I fitted ours and technology has undoubtedly moved on.

 

Edited to add:

 

Just had a quick look.  Technology has moved on and there are now wireless controls available, so you can indeed fit a battery powered wireless controller in the bathroom, with the LV switching done by a receiver outside the zones.

Edited February 8, 2017 by JSHarris
Technology has moved on!

[Redoctober]

 

Thanks for all your contributions I really do appreciate it.  I’m sure there are others out there who do so too.

 

@Barney12 summed this up nicely - The need to put UFH upstairs in a well insulated home really does seem to split the audience! 

 

So by way of a round up and after considering these very useful thoughts -

@Nick - I'm also trying to solve this same dilemma. Part of it depends on what is driving your under floor heating on the ground floor. If you are running a heat pump then it seems a shame after the big up-front cost of installing it, to then use a less efficient system upstairs.

@AliG -My wife is insistent on having UFH so that the tiles are warm. But the reality is the heating will hardly ever be on so they won't benefit from it. I may have to run the heating in the en suite at a higher temperature than the rest of the house just to warm the tiles

@jack – thanking you in particular for your honesty - If I were doing this all again, I'd definitely include UFH in the bathrooms, just to take the chill off the tiles.  

 

And comments from the UFH people which I thought would be useful to share -

We think it would be beneficial if we explained to you the advantages to having under floor heating throughout, against the disadvantages of having radiators or part UFH plus radiators in some rooms.

From a design and installation perspective, it is far easier and more straightforward for all concerned if UFH is being installed, to have it on the whole floor rather than in part of an upper floor.  From an energy efficiency perspective it is definitely more efficient throughout because the flow temperature to UFH is much lower than radiators at the higher temperature they require.  Having UFH across the whole floor will enable the customer to achieve a 6 star energy rating, rather than a 4 star because of the radiators, which would also result in a reduction in RHI payments.  And finally, from the customer’s perspective, there are additional flow temperature control components required to service the radiator distribution, which put the cost up.  More equipment means more potential for things to go wrong.  UFH throughout is the far simpler and most cost effective method for short and long term effectiveness.

 A lot of people have gained the impression from some external influence (could be an article in a homebuilding magazine or a grand designs type programme), that you do not nowadays need heat in upper rooms.  This is completely false.  Even with a very well insulated house, for a building warrant to be granted, building control will need evidence to show that the whole house can be heated to the required room temperatures to satisfy the building regulations.  It is highly unlikely that the required temperatures can be achieved without what we would call a primary heat input.  Contrary to popular belief, under floor heating on a ground floor definitely does not heat rooms on an upper floor.  MVHR is not a primary heat input either, although it does assist by pre-heating the incoming fresh air.

All this has led us to a decision that we will go for UFH upstairs -

 Thanks again PW.

[Jeremy Harris]

That's an interesting, and demonstrably false, statement from the UFH people!  I particularly like this, rather definitive, statement: 

 

Quote

A lot of people have gained the impression from some external influence (could be an article in a homebuilding magazine or a grand designs type programme), that you do not nowadays need heat in upper rooms.  This is completely false.  Even with a very well insulated house, for a building warrant to be granted, building control will need evidence to show that the whole house can be heated to the required room temperatures to satisfy the building regulations.  It is highly unlikely that the required temperatures can be achieved without what we would call a primary heat input.  Contrary to popular belief, under floor heating on a ground floor definitely does not heat rooms on an upper floor.

 

Well, I can say that our "impression"  (accurately measured to +/-0.1 deg C and logged) is that when it's around zero or below outside, our first floor (that has no heating at all) never drops below 1 degree lower than the ground floor (that has UFH).

 

Basically, what the UFH people are saying is untrue, particularly their reference to a "very well insulated house".  I'm pretty sure others here (like Tony) will confirm that the first floor will be heated quite adequately in a well-insulated house by just the heat rising from the ground floor.  Our concern is that the bedrooms may actually be a little too warm, even with no heating, as, like a fair few people, we prefer the bedroom temperature to be no higher than about 18 deg C, and currently we've never seen ours drop below about 19.5 deg C, even in the coldest weather.  That's without the towel rails in the adjacent bathrooms being turned on and in an unoccupied house, hence our concern about the bedrooms getting a bit too warm for us.

 

There is a case to be made for floor comfort heating with stone or tile flooring in bathrooms, for sure, but that's really about making the floor comfortable to walk on with bare feet when you've just stepped out of the shower or bath.

 

If they'd left out the reference to a "very well insulated house" then I would have said they may well have a case for some upper floor heating, but their statement as it stands smacks of being a sales pitch to sell more UFH to me!

[Ferdinand]

Two questions:

 

1 - Is that in-CU timer also an MCB? Or does need a second slot?

 

2 - I am not familiar with a 4 or 6 star energy rating. Can anyone advise? With the talk of Building Warrants, is it perhaps another differently Scottish thing?

Edited February 8, 2017 by Ferdinand

[AliG]

It does pose an interesting question. The people without heating upstairs, have BC taken on board that heat rising from downstairs will achieve the minimum temperature requirements for habitable rooms.

 

If the house was run through Jeremy's heat loss calculator, I guess you would find it hardly needs any heat input and therefore heat all over the house is not necessary.

 

The response from the UFH people is partly correct in that it mentions the RHI, so if you are using an ASHP, it would not be a good idea to try and run traditional radiators on it upstairs as they run at a much higher temperature the UFH and a temperature that would not be efficient with an ASHP. However, if you calculate the required heat input for your house I suspect you will need either none upstairs, or you could run radiators upstairs at the same temperature as the UFH to provide the necessary heat input. I believe that some people on the site also run oversized radiators so they can run at a cooler temperature with an ASHP.

 

Generally heating companies are just not used to the low heat requirements of a well insulated house and will recommend massively over specified systems today. The first spec I had for my house had a 60kW boiler which would have required me to go to the extra expense of upping the gas supply as well as being oversized and running inefficiently. Once I run the calculations I showed them 30kW was adequate and we settled on 40 as it will allow faster hot water heating.

[Redoctober]

38 minutes ago, JSHarris said:

That's an interesting, and demonstrably false, statement from the UFH people! 

 

Maybe so and I'm not here to defend them but it's like most things I suppose, a degree of caution has to be applied because there are going to be exceptions to the rule and perhaps they were talking or trying to explain things, in a more general manner.

Any statement or comment could be considered to be wrong regardless of topic or subject matter I'm sure, but I'm equally certain, this was said with the best intentions and to cover more general situations. Perhaps their views would change, if dealing specifically with a particular set of circumstances like your @JSHarris - for example.

PW

[joe90]

Well my plans showed UFH only downstairs and BC have not mentioned it and passed the plans so I don't see it as a problem. I stayed with a neighbour recently and they have an ASHP running oversized radiators but not a well insulated house and I found their house chilly.

[Jeremy Harris]

9 minutes ago, Ferdinand said:

Two questions:

 

1 - Is that in-CU timer also an MCB? Or does need a second slot?

 

2 - I am not familiar with a 4 or 6 star energy rating. Can anyone advise? With the talk of Building Warrants, is it perhaps another differently Scottish thing?

 

 

I can answer the first, but not the second, question.  Those DIN rail timers have no circuit protection capability at all, so need to have an upstream MCB as the very minimum, with an RCD before that if it's a standard split CU.

 

I've used mine in CU housings that aren't being used as CUs, because they are often the cheapest way of getting a DIN rail wiring box.  For example, my ASHP,  UFH and DHW control box uses a small CU, fed from a fused spur, that contains four DIN rail mount relays, a DIN rail mount 12V power supply and some DIN rail mount cable junction boxes.  Not only was it a cheap way to get a DIN rail box, but having a see-through lid allows me to see the relay LEDs.

Edited February 8, 2017 by JSHarris

[ToughButterCup]

@JSHarris, your hard evidence is not what sales folk want. But it is exactly what I need, so as usual, thanks.

 

With, in my case 60+ years of being told to put-another-log-on-the-fire, and  a few  years of Uncle Tom Cobley and All looking at me in disengaged disbelief when I talk of Passiv standards (about two cat's worth of heat per per meter squared per annum), I have come to realise it's HARD for anyone to get their head round how little just a little heat is      

(Apologies @SteamyTea)

 

And when the listener has nothing, nothing at all invested in your house, disengagement on the part of the listener/ reader is the norm.

 

@Redoctober's summary of the arguments is interesting. The psychology related to warm wet feet appears to be important. We (almost all) have very little experience of ablutions where we have warm soles, but cold lower legs - because yer legs are wet, and your soles warmed by ufh. An expensive Afghan rug would have the same effect -but be really stupidly impracticable. 

What @Nickfromwales, you've got two afghans (his 'n hers) in your shower?  Soz mate!

[jack]

2 minutes ago, joe90 said:

Well my plans showed UFH only downstairs and BC have not mentioned it and passed the plans so I don't see it as a problem. 

 

Exactly my experience. Private building control typically couldn't care less about this type of thing I suspect.

[joe90]

1 minute ago, jack said:

 

Exactly my experience. Private building control typically couldn't care less about this type of thing I suspect.

Mine is local council, just hoping it's not a problem, actually he is a very nice guy with a level head and very accepting of different build types.

[Redoctober]

 

8 minutes ago, joe90 said:

Well my plans showed UFH only downstairs and BC have not mentioned it and passed the plans so I don't see it as a problem

 

4 minutes ago, jack said:

Exactly my experience. Private building control typically couldn't care less about this type of thing I suspect.

 

I should have mentioned we are talking Scottish Regs. here not English, so it would be interesting to hear the experiences of those North of the Border so to speak.

[Redoctober]

8 minutes ago, recoveringacademic said:

@JSHarris, your hard evidence is not what sales folk want. But it is exactly what I need, so as usual, thanks.

 

Absolutely, but equally, when heeding the sage advice, one has to remember it often relates to a set of specific circumstances. The old adage " judge every case on its own merits" comes to mind.

[AliG]

In my case the heating supplier calculated required heat based on generic inputs until they had all the data. Have you given them the insulation values for your house and asked them to calculate how much heat is actually needed?

Edited February 8, 2017 by AliG

[Redoctober]

2 minutes ago, AliG said:

In my case the heating supplier calculated required heat based on generic inputs until they had all the data. Have you given them the insulation values for your house and asked them to calculate how much heat is actually needed?

 

Not quite @AliG this will no doubt be covered in due course - we are just at the stage of drawing up the Building Reg. Plans etc. and the question of UFH upstairs or not was raised.

[Nickfromwales]

16 minutes ago, recoveringacademic said:

What @Nickfromwales, you've got two afghans (his 'n hers) in your shower?  Soz mate!

Say what? You been licking great crested newts again ? ?

[ToughButterCup]

54 minutes ago, Nickfromwales said:

Say what? You been licking great crested newts again ? ?

 

Mmmm, lovely. Except those that were from the compost heap.