UFH versus Radiators

[Lesgrandepotato]

8 hours ago, Ferdinand said:

Personally I would lie down on the ufh. ?

That’s exactly what I do! 

[Lesgrandepotato]

I don’t think I could go back to Rads after UFH. It’s a fabulous feeling of luxury. 

[Ferdinand]

Also worth a note that ufh is excellent at frying washing and shoes if you need it done quickly - either spread out or on a drying frame.

 

One trick is to have a warm spot or room - my own inner downstairs bathroom gets seriously warm.

 

F

[Ferdinand]

10 hours ago, JSHarris said:

skirting radiators

 

At the moment I only have bad experiences of skirting rads; they seem to click interminably.

 

I think we may need to differentiate between those "inside skirting" rads, and the ankle-height ones mounted at skirting level.

 

The installation I have in a tenanted property were supposed to be the former but were ordered as the latter by mistake.

F

[Jeremy Harris]

1 hour ago, Ferdinand said:

 

At the moment I only have bad experiences of skirting rads; they seem to click interminably.

 

I think we may need to differentiate between those "inside skirting" rads, and the ankle-height ones mounted at skirting level.

 

The installation I have in a tenanted property were supposed to be the former but were ordered as the latter by mistake.

F

 

Depends how hot they need to get I suspect.  Our UFH rarely ever gets the floor more than 1°C above room temperature, so we can't actually feel that the floor is warm at all.  If we had skirting rads instead they would need to run a bit warmer, but I'd guess they'd not need to run at more than around 30°C or so. 

[Lesgrandepotato]

2 hours ago, Ferdinand said:

Also worth a note that ufh is excellent at frying washing and shoes if you need it done quickly - either spread out or on a drying frame.

 

This led to our first post move in disaster. We got in for the 22nd Dec, set up the tree, laid out the presents under it and went to bed. 

Turns out putting chocolates on a heat source.... 

[Lesgrandepotato]

2 hours ago, Ferdinand said:

 

One trick is to have a warm spot or room - my own inner downstairs bathroom gets seriously warm.

 

F

 

Thinking about it, that’s exactly how our internal heated log store is working. We have space for a couple of dumpies under the stairs and it’s kept tippy top by being heated and further dried.

[Ed Davies]

3 hours ago, Ferdinand said:

frying washing

 

Why would you want to do that?

[Hecateh]

21 hours ago, ragg987 said:

 

One thing to note in UFH vs rads is that rads are great when you come in after a walking the dog in the cold and need to warm your body up - you can lean against the warm surface and this is a lovely feeling. You don't get this with UFH.

The warmth on the feet is more than enough - if my feet are warm the rest of me rarely feels cold - but I can have cold feet even when I feel generally warm

 

21 hours ago, Ferdinand said:

Personally I would lie down on the ufh. ?

 

Yep - I've done that

 

13 hours ago, Lesgrandepotato said:

I don’t think I could go back to Rads after UFH. It’s a fabulous feeling of luxury. 

Me neither.  

This house is obviously better insulated than my old draughty place (which I know is a large part of it) but in winter last year I was running the central heating most of the day.  Here an hour or so in the morning and it stays warm enough all day with another hour or 2 early evening

[Ferdinand]

 

3 hours ago, Ed Davies said:

7 hours ago, Ferdinand said:

frying washing

 

Why would you want to do that?

 

Because at weekends I am Delusional Dan, the Multitasking Man.

[MirandaPoth]

We have been living in our new MBC-built passiv-standard house for the last 4 months. We have gas-heated UFH downstairs (in the slab), electric UFH in two of the bathrooms upstairs and an Airflow MVHR system. Having come from an old, standard-build house we were concerned about heating this house; we had no need to be. As I read previously on this forum, we spend more time figuring out how to keep the house cool than we do keeping it warm. Our 'leap of faith' decision (based on MBC advice) to have no heating in the bedrooms has been justified.

 

The downstairs UFH, set to 21 deg C in most rooms, rarely comes on. Even in October/November, before we had any heating or MVHR on in the house, it was a pleasantly-warm 15 or so degrees inside the house, day in, day out. We have no heating in the bedrooms, just what comes from the sun and the MVHR, and it's maybe a degree or two cooler in the bedrooms than downstairs, which is fine. When it's sunny we have to close the blinds on the triple-glazed south & west-facing windows and/or open the Veluxes otherwise it gets too hot, even when it's around 10 deg C outside; the MVHR captures and re-uses an amazing amount of the outgoing heat. (We were warned that we had too many windows on the west side; they were right, but hey, we like to be warm, and our MVHR has a cooling add-on for the summer if we need it.)

 

UFH is certainly much slower to take effect than radiators, and there's no nice area on which to warm your feet/back. But I would much rather have the even, fresh heat of UFH + MVHR than radiators any day ?

[Ferdinand]

5 hours ago, JSHarris said:

7 hours ago, Ferdinand said:

 

At the moment I only have bad experiences of skirting rads; they seem to click interminably.

 

I think we may need to differentiate between those "inside skirting" rads, and the ankle-height ones mounted at skirting level.

 

The installation I have in a tenanted property were supposed to be the former but were ordered as the latter by mistake.

F

 

Depends how hot they need to get I suspect.  Our UFH rarely ever gets the floor more than 1°C above room temperature, so we can't actually feel that the floor is warm at all.  If we had skirting rads instead they would need to run a bit warmer, but I'd guess they'd not need to run at more than around 30°C or so. 

 

That is very possibly the case.

As someone with no experience of self-building passive houses (yet), and a bandaged finger, I need you to come and live in my garden for 3 years and build me one. ?

 

I can supply a slightly leaky 8x8 shed for weekday accommodation and storage, which includes a complimentary (non-passive) cat-flap for potential companionship.

Edited April 28, 2019 by Ferdinand

[TerryE]

UFH every time.  Like many others we have an MBC twin-wall with a blown cellulosic insulation filler.  We also have an exterior stone stone to fit in with the local context.  UFH on the ground floor heated by an inline 3kW (Willis) heater.  No heating on the 1st or 2nd floor apart from an electrical rad in the master bedroom en-suite.  No rads anywhere.  Cheap, simple effective.

 

On 27/04/2019 at 12:21, jonM said:

I was given a very strong recommendation by an experienced Passivhaus M&E designer and architect to use radiators on the basis it is cost effective, quicker to respond than burying pipes in a slab and easier to maintain.

 

I have to offer a dissenting opinion to @jonM's designer.  I feel that he really misses the main point here: if you have a reasonable specification passive design (our slab, TF + insulation and air-tightness cost less than our stone skin so it was hardly an expensive option), then you just keep the whole house at the same temperature all day and year round.  It's just not worth trying to save the odd £100 p.a. by trying to have different zones or shaping the heat across the day.  A couple of times we've dropped our heating for a day or two.  We didn't notice because the house only loses about 1°C / day in temperature with no heating; and it then takes a couple of days to regain this, and if you try to force it you end up in an over-compensating roller coaster.  Our 1st floor might be a degree or so cooler than the ground floor in winter, but we prefer that.  I don't know how we could get it much cooler if we tried.

 

As with Jeremy and others, the supplier's site team tied the UFH pipework to the rebar grid in the slab before the pour: a ½ day's work instead of all those rads and internal plumbing.  No comparison, IMO.  The difference is that there is no maintenance needed for the pipework in the slab for the life of slab, but rads and TRVs etc. will need maintenance.  Also not having those bloody rads under the windows everywhere just makes decorating and dressing all the rooms so much more straightforward.

 

 

 

Edited April 28, 2019 by TerryE

[jonM]

12 hours ago, TerryE said:

The difference is that there is no maintenance needed for the pipework in the slab for the life of slab,

 

I get the points made around decorating, aesthetics etc, etc, they are all valid and among self  builders, UFH is undoubtedly the most popular system for some good reasons. 

In terms of the comment around maintenance - I think the longevity of UFH is unproven and if maintenance is required it will be very messy indeed. I am aware for example of a 15 year old UFH system that has sprung a leak and will require the concrete floor to be dug up to find the leak.

[TerryE]

@jonM,  in our last house, we had one rad that spontaneously developed a pinhole leak over a weekend when we were away and came home to find the landing carpet and living room carpet below sodden.  We also had 3 TRVs need replacing whilst we were in the house.  My son has just spent £300 getting a leak fixed in his CH system in his 10mm copper piping in the ground floor concrete.  So that's two instances where I can personally testify of major failure in conventional CH systems.

 

On the other hand the PexAlPex UFH are continuous in slab (no joints because I watched them lay it). I am confident that jointless PexAlPex UFH will out live me.

Edited April 29, 2019 by TerryE

[Declan52]

46 minutes ago, jonM said:

 

I get the points made around decorating, aesthetics etc, etc, they are all valid and among self  builders, UFH is undoubtedly the most popular system for some good reasons. 

In terms of the comment around maintenance - I think the longevity of UFH is unproven and if maintenance is required it will be very messy indeed. I am aware for example of a 15 year old UFH system that has sprung a leak and will require the concrete floor to be dug up to find the leak.

Use a thermal camera to locate the damaged pipe. It will be easily found.

In my previous house I had a radiator spring a leak and put many litres of dirty water over carpet,bedding and curtains all which needed binned. Had a few leaks on fittings as well with the downstairs living room flooded on boxing Day which ended up an insurance job as the wooden floor was destroyed. 

I like my ufh as it's a nice heat to live with. You don't have a warm part of the room and a cold part it's all just nice. Walking round in your socks with the floor being warm is just a different sensation.  I have rads up stairs and yes they are great as they heat the kids rooms up in under an hour but the heat doesn't last as long as downstairs, within 2 hrs that warm feeling is gone even though the rooms aren't cold. It takes about 60mins to start to feel some heat with the ufhbut that heat in the floor could still be there in 4 -5 hrs later.

If I take the run of myself and build another house no question it will have ufh.

 

 

[jack]

3 hours ago, Declan52 said:

I like my ufh as it's a nice heat to live with. You don't have a warm part of the room and a cold part it's all just nice. Walking round in your socks with the floor being warm is just a different sensation. 

 

I'll tell you what's a nice sensation: coming into the house in the middle of summer after walking the dog on a baking hot day, taking your shoes off and walking on a concrete floor at around 19-20 degrees C. It's the sort of cool you get when you walk into a cave or a cathedral. 

[Ed Davies]

19 hours ago, TerryE said:

The difference is that there is no maintenance needed for the pipework in the slab for the life of slab, but rads and TRVs etc. will need maintenance. 

 

UFH manifolds, etc, presumably need as much maintenance as TRVs.

 

The main reason radiators need maintenance is because they're made of metal, not plastic. Why don't we make them out of plastic?

[TerryE]

19 minutes ago, Ed Davies said:

UFH manifolds, etc, presumably need as much maintenance as TRVs.

 

Fair point Ed.  But we operate our three loops as a single zone so we don't have TRVs on the manifold.  The other advantage is that all this stuff in is a single services cupboard with a concrete floor, so no risk to carpets.

[Stones]

1 hour ago, Ed Davies said:

 

The main reason radiators need maintenance is because they're made of metal, not plastic. Why don't we make them out of plastic?

 

I'm guessing steel is a far better transmitter for heat.  For robustness, would plastic not end up being thicker and therefore in comparison to steel, the radiators would be bigger?