After lots of helpful comments on my plight to redesign my Dad's
CH using a thermal store system, I was wondering if anyone could comment
on this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump
assembly by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents
70+C water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???

Would you say my instincts are correct or would this type of regulation
actually work?

Ta muchly,

Timbo
--
Tim Southerwood

On Thu, 04 Nov 2004 13:25:33 +0000, Tim wrote:

After lots of helpful comments on my plight to redesign my Dad's CH
using a thermal store system, I was wondering if anyone could comment on
this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump assembly
by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents 70+C
water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???


OK - one adittional thing... I just found the installation manual on their
website and it does mention that the heating pipe must be run in a
double-spiral config, so a flow and return pipe are alway adjacent.

Wonder if that's how they make such a simple system work? ie they are
relying on the thermal conductivity of the screed to reduce the
inflow/outflow differential and also using the return flow to indrectly
cool the inflow... Sounds didgey - but it *could* just work?

Timbo

"Tim" wrote in message
news
After lots of helpful comments on my plight to redesign my Dad's
CH using a thermal store system, I was wondering if anyone could comment
on this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump
assembly by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents
70+C water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???

Would you say my instincts are correct or would this type of regulation
actually work?

Ta muchly,

Timbo
--
Tim Southerwood


Hi Tim
The valve is a Danfoss http://tinyurl.com/4blyr
I used them in my conservatory.
No mixers, works a treat.
We use the room all the year round. It is super I wish I could do the whole
house like it.
Baz

Would you say my instincts are correct or would this type of regulation
actually work?

It didn't give me a warm fuzzy feeling reading the specs. The "solid floor
only" restriction is probably about the inability to limit temperatures to
sensible values. There's probably an item in the instruction manual saying
to run the boiler at 50C or something.

You really need to go the pump/TMV route.

Christian.

OK - one adittional thing... I just found the installation manual on their
website and it does mention that the heating pipe must be run in a
double-spiral config, so a flow and return pipe are alway adjacent.

Ah. That makes more sense. It controls the power by varying flow speed. As
this will produce a large temperature difference, you need to have the hot
entrance pipes next to the cold exit pipe to ensure average heat transfer
over the whole area.

However, the system would lead to localised hot spots, unless the floor is
sufficiently conductive to ensure that the hot and cold parts produce an
average.

At one end of the spiral, you get a 70C and a 20C pipe. In the middle of the
room, you both pipes finally meet at around 45C. The approach gives an
average 45C anywhere in the room, with some variation, however, depending on
the exact flow rate chosen.

I'd probably still want a proper TMV and pump, though, even for a solid
floor. I like the idea of a simple thermostat setting to set the floor
temperature.

Christian.

On Thu, 04 Nov 2004 13:41:26 +0000, Christian McArdle wrote:

Would you say my instincts are correct or would this type of regulation
actually work?

It didn't give me a warm fuzzy feeling reading the specs. The "solid
floor only" restriction is probably about the inability to limit
temperatures to sensible values. There's probably an item in the
instruction manual saying to run the boiler at 50C or something.

Hi Christian,

The only fuzzy feeling I got was "ooh, that's simple to install and small
and neat".

They do claim the boiler can run at a standard 81/70C.

You really need to go the pump/TMV route.

I'm completely sure your instinct is well founded - I'm just being cheap
and was wondering whether it is too good to be true or not. I notice that
Baz found his Danfoss works in practise, so I'm still weighing it up...

'twoud be neat and simple though for one single little circuit - it seemed
a lot of effort to install a 4port mixer and an extra pump for one room.


Christian.

Thanks as ever for your expert opinion.

Cheers

Timbo

On Thu, 04 Nov 2004 13:40:36 +0000, pjdesign wrote:


Hi Tim
The valve is a Danfoss http://tinyurl.com/4blyr
I used them in my conservatory.
No mixers, works a treat.
We use the room all the year round. It is super I wish I could do the whole
house like it.
Baz

Hi Baz. Thanks for the feedback. I'm still weighing it up :?

Timbo

"pjdesign" wrote in message
...

"Tim" wrote in message
news
After lots of helpful comments on my plight to redesign my Dad's
CH using a thermal store system, I was wondering if anyone could comment
on this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump
assembly by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents
70+C water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???

Would you say my instincts are correct or would this type of regulation
actually work?

Ta muchly,

Timbo
--
Tim Southerwood


Hi Tim
The valve is a Danfoss http://tinyurl.com/4blyr
I used them in my conservatory.
No mixers, works a treat.
We use the room all the year round. It is super I wish I could do the
whole
house like it.
Baz

Make sure the flow temp is no more than 50-55C. A mixer should be used to
ensure this, or a condensing boiler set to 50Cish and a priority system for
DHW where the boiler temp is ramped right up. ECO-Hometec do boiler just
for this.

'twoud be neat and simple though for one single little circuit - it seemed
a lot of effort to install a 4port mixer and an extra pump for one room.

Is a pump and TMV that much work to install? I suppose as time goes on, I
forget that these things could be a little intimidating if you haven't done
much plumbing before. I presume someone has packaged the lot into one box,
so you just connect the room up to 2 holes and the CH circuit up to the
others and apply electricity.

Christian.

"Tim" wrote in message
news
On Thu, 04 Nov 2004 13:41:26 +0000, Christian McArdle wrote:

Would you say my instincts are correct or would this type of regulation
actually work?

It didn't give me a warm fuzzy feeling reading the specs. The "solid
floor only" restriction is probably about the inability to limit
temperatures to sensible values. There's probably an item in the
instruction manual saying to run the boiler at 50C or something.

Hi Christian,

The only fuzzy feeling I got was "ooh, that's simple to install and small
and neat".

They do claim the boiler can run at a standard 81/70C.

You really need to go the pump/TMV route.

I'm completely sure your instinct is well founded - I'm just being cheap
and was wondering whether it is too good to be true or not. I notice that
Baz found his Danfoss works in practise, so I'm still weighing it up...

Having 80C water through UFH pipes is ridiculous. It makes the floor far
too, hot. Then there is expansion contraction, etc. The Danfoss system is
assuming that the supply water is less than 55C.

'twoud be neat and simple though for one single little circuit - it seemed
a lot of effort to install a 4port mixer and an extra pump for one room.

No need for a 4 port mixer. A normal cheap 3-port will do.

On Thu, 04 Nov 2004 14:35:43 +0000, Christian McArdle wrote:

'twoud be neat and simple though for one single little circuit - it seemed
a lot of effort to install a 4port mixer and an extra pump for one room.

Is a pump and TMV that much work to install? I suppose as time goes on, I
forget that these things could be a little intimidating if you haven't done
much plumbing before. I presume someone has packaged the lot into one box,
so you just connect the room up to 2 holes and the CH circuit up to the
others and apply electricity.

Christian.

I suppose not. It was mostly the extra pump that put me off, what with
standard CH pumps being bulky. Unless they do little pumps for this sort
of thing?

Tim

"IMM" wrote in message
...
SNIP
Having 80C water through UFH pipes is ridiculous. It makes the floor far
too, hot. Then there is expansion contraction, etc. The Danfoss system
is
assuming that the supply water is less than 55C.

SNIP

IMM.
Read the link http://tinyurl.com/4blyr.

"Maximum flow temperature 90°C "

" Used in systems which are predominately heated by radiators (normal system
design temperatures 82/71°C) and where Underfloor Heating represents only a
minor part of the system, for example a single room or small extension "

The water will not flow through the pipes at 82/71 because the water is only
let out of the system after it has given up some of it's heat, so it is only
topping up.

Baz

On Thu, 04 Nov 2004 14:47:30 +0000, IMM wrote:

No need for a 4 port mixer. A normal cheap 3-port will do.

What's the practical difference between 3 and 4 port? I know roughly what
they look like, so I presume the 3 port just short circuits the pipework
under the floor when less heat is needed?

Would you use a 4 port if you needed more than one circuit off it?

Thanks

Tim

"Tim" wrote in message
news
On Thu, 04 Nov 2004 14:35:43 +0000, Christian McArdle wrote:

'twoud be neat and simple though for one single little circuit - it
seemed
a lot of effort to install a 4port mixer and an extra pump for one
room.

Is a pump and TMV that much work to install? I suppose as time goes on,
I
forget that these things could be a little intimidating if you haven't
done
much plumbing before. I presume someone has packaged the lot into one
box,
so you just connect the room up to 2 holes and the CH circuit up to the
others and apply electricity.

Christian.

I suppose not. It was mostly the extra pump that put me off, what with
standard CH pumps being bulky. Unless they do little pumps for this sort
of thing?

UFH is going to take up space with manifolds etc. If it is not designed and
controlled properly they are perform terribly badly.

"pjdesign" wrote in message
...

"IMM" wrote in message
...
SNIP
Having 80C water through UFH pipes is ridiculous. It makes the floor
far
too, hot. Then there is expansion contraction, etc. The Danfoss system
is
assuming that the supply water is less than 55C.

SNIP

IMM.
Read the link http://tinyurl.com/4blyr.

"Maximum flow temperature 90°C "

" Used in systems which are predominately heated by radiators (normal
system
design temperatures 82/71°C) and where Underfloor Heating represents only
a
minor part of the system, for example a single room or small extension "

The water will not flow through the pipes at 82/71 because the water is
only
let out of the system after it has given up some of it's heat, so it is
only
topping up.

That is nonsense. A 90C floor is very uncomfortable to walk on.

From: "Tim"
Subject: Underfloor wet heating - alternative to mixer?
Date: 04 November 2004 15:15

On Thu, 04 Nov 2004 14:47:30 +0000, IMM wrote:

No need for a 4 port mixer. A normal cheap 3-port will do.

What's the practical difference between 3 and 4 port? I know roughly what
they look like, so I presume the 3 port just short circuits the pipework
under the floor when less heat is needed?

Would you use a 4 port if you needed more than one circuit off it?

A 4-port proportioanlly reduces one loop in favour of another. If mid way
50-50 to each. If open 25% then 25% to one and 75% to the other.

The simplest systems are from the likes of Polyplumb. Go to their web site.
their equipment is expensive, but you can buy the component parts and do it
yourself.

"IMM" wrote in message
...
snip
That is nonsense. A 90C floor is very uncomfortable to walk on.

RTFM.
The floor does not get any were near 90.
Surface temp is 20 to 25.
I am using this system in my conservatory.
Baz

On Thu, 04 Nov 2004 16:36:36 +0000, IMM wrote:

A 4-port proportioanlly reduces one loop in favour of another. If mid
way 50-50 to each. If open 25% then 25% to one and 75% to the other.

Hi

Yes - I understand that bit - just wondered in what situations a 4 port
would be called for, rather than a 3 port?


The simplest systems are from the likes of Polyplumb. Go to their web
site. their equipment is expensive, but you can buy the component parts
and do it yourself.

Wow - you're not joking:

[Quote from
http://www.inspiredheating.co.uk/aca...NG_PACKS.html]

POLYPLUMB UNDERFLOOR HEATING PACK FOR 20 M SQ - SOLID FLOOR

Price you pay including VAT: £715.00

System includes Polyplumb pipe laid at 100mm centres to cover 20 m sq,
Polyplumb easy lay floor panels, Polyplumb edge insulation, Polyplumb
zonal regulation unit (consisting of pump, mixing valve and pipe stat),
Honeywell room thermostat, Polyplumb pipe cutter as well as sufficient
Polyplumb Pipe Stiffeners, Spigot Elbows and Tees.

System is designed to connect to existing central heating. Pack excludes
necessary insulation required for floor slab
[End quote]

Timbo

"pjdesign" wrote in message
...

"IMM" wrote in message
...
snip
That is nonsense. A 90C floor is very uncomfortable to walk on.

RTFM.
The floor does not get any were near 90.
Surface temp is 20 to 25.
I am using this system in my conservatory.
Baz

What is the flow temp in?

"Tim" wrote in message
news
On Thu, 04 Nov 2004 16:36:36 +0000, IMM wrote:

A 4-port proportioanlly reduces one loop in favour of another. If mid
way 50-50 to each. If open 25% then 25% to one and 75% to the other.

Hi

Yes - I understand that bit - just wondered in what situations a 4 port
would be called for, rather than a 3 port?

Look at:
http://www.leemick.co.uk/ufh/tech/36345.htm

If the 4-port is half open 50% of the boilers flow through the UFH circuit
and 50% back to the boiler. If it 100% one way it goes all into the UFH.
100% the other way 100% back top the boiler by-passing the UFH. The boiler
return always has the same volume of flow back to it.

The simplest systems are from the likes of Polyplumb. Go to their web
site. their equipment is expensive, but you can buy the component parts
and do it yourself.

Wow - you're not joking:

[Quote from
http://www.inspiredheating.co.uk/aca...NG_PACKS.html]

POLYPLUMB UNDERFLOOR HEATING PACK FOR 20 M SQ - SOLID FLOOR

Price you pay including VAT: £715.00

System includes Polyplumb pipe laid at 100mm centres to cover 20 m sq,
Polyplumb easy lay floor panels, Polyplumb edge insulation, Polyplumb
zonal regulation unit (consisting of pump, mixing valve and pipe stat),
Honeywell room thermostat, Polyplumb pipe cutter as well as sufficient
Polyplumb Pipe Stiffeners, Spigot Elbows and Tees.

System is designed to connect to existing central heating. Pack excludes
necessary insulation required for floor slab
[End quote]

Timbo

"IMM" wrote in message
...

"pjdesign" wrote in message
...

"IMM" wrote in message
...
snip
That is nonsense. A 90C floor is very uncomfortable to walk on.

RTFM.
The floor does not get any were near 90.
Surface temp is 20 to 25.
I am using this system in my conservatory.
Baz

What is the flow temp in?



Boiler Temp 80 ish.
Baz

On Thu, 04 Nov 2004 17:34:20 +0000, IMM wrote:


"Tim" wrote in message
news
On Thu, 04 Nov 2004 16:36:36 +0000, IMM wrote:

A 4-port proportioanlly reduces one loop in favour of another. If
mid way 50-50 to each. If open 25% then 25% to one and 75% to the
other.

Hi

Yes - I understand that bit - just wondered in what situations a 4 port
would be called for, rather than a 3 port?

Look at:
http://www.leemick.co.uk/ufh/tech/36345.htm

If the 4-port is half open 50% of the boilers flow through the UFH
circuit and 50% back to the boiler. If it 100% one way it goes all into
the UFH. 100% the other way 100% back top the boiler by-passing the UFH.
The boiler return always has the same volume of flow back to it.



Doh! slaps self Yes - that would be an irrelevant consideration in my
setup,so I didn't think of it - but I could see that it would matter in
certain types of installation.

Ta.

Timbo

On Thu, 04 Nov 2004 17:35:02 +0000, pjdesign wrote:



Boiler Temp 80 ish.
Baz

OK - can help from a physics POV here... The inflow pipe will try to
get to 80C...

But with a low flow rate, it will be unable to maintain the surface of the
floor at a high temperature. Sufficiently low flow rate, and it won't even
manage to maintain a decent thermal gradient from the pipe to the surface.

So the low flow rate 80C water entering the pipe will be instantly cooled
and will lose a little bit of heat (as in joules) into the floor and thus
drop temperature quickly.

Yes - that works in theory...

Rather like spilling exactly one drop of boiling water on your hand.
Doesn't really do much.

Tim

On Thu, 04 Nov 2004 17:41:40 +0000, "Tim" wrote:

If the 4-port is half open 50% of the boilers flow through the UFH
circuit and 50% back to the boiler. If it 100% one way it goes all into
the UFH. 100% the other way 100% back top the boiler by-passing the UFH.
The boiler return always has the same volume of flow back to it.



Doh! slaps self Yes - that would be an irrelevant consideration in my
setup,so I didn't think of it - but I could see that it would matter in
certain types of installation.

Hi,

What sort of floor are you planning to have? If stone then a
counterflow system should be fine. It may be warmer near the
flow/return end, so that part could be located where the most warmth
is needed.

Also what is underneath will make a difference, if a thick slab then
it will average out the heat better than a thin screed and insulation.

If you have a radiator valve over the warm end, that could accelerate
it's switching off as the floor warms up so to help minimise
overshoot.

If you want to limit the temperature of the room overall, then another
radiator valve in series elsewhere will control the room temperature.

Eg for a conservatory, if more heat is desired by the windows, start
there and zig zag flow and return back towards the wall of the house.

Also spacing the flow/return pairs of tubes slightly wider at the
flow/return end and slightly closer at the other end will help to
balance the output if needed.

If really concerned about it try temporarily laying the pipes into
sand with the tiles on top, that would give some idea of what to
expect.

cheers,
Pete.

Tim wrote:

After lots of helpful comments on my plight to redesign my Dad's
CH using a thermal store system, I was wondering if anyone could comment
on this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump
assembly by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents
70+C water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???

Would you say my instincts are correct or would this type of regulation
actually work?


I think yiou have it right,.

Bite the bullet and use the proper system.

Ta muchly,

Timbo

Christian McArdle wrote:
'twoud be neat and simple though for one single little circuit - it seemed
a lot of effort to install a 4port mixer and an extra pump for one room.


Is a pump and TMV that much work to install? I suppose as time goes on, I
forget that these things could be a little intimidating if you haven't done
much plumbing before. I presume someone has packaged the lot into one box,
so you just connect the room up to 2 holes and the CH circuit up to the
others and apply electricity.


Thats what I bought - polyplumb 8 way manifold,aux pump, two way valve
amd loads of isoaltaion and drain taps and balancing flow meters for
each circuit and a temp reduction valve. All for about £250 IIRC, and it
was a piece of **** to install. The manifold handles all the polypipe
underfloor circuits, and the two main connections simly go to flow and
return on the boiler.

The only tricky bit was to put in a relay so that the boiler pump could
be called up for ordinary CH without forcing the UFH pump on as well.




Christian.

IMM wrote:


UFH is going to take up space with manifolds etc. If it is not designed and
controlled properly they are perform terribly badly.


My manifold/pump assy. takes up less space than the radiator I have in
the airing cupboard.

Anything that isn't designed properly or controlled properly is going to
perform badly. You are a classic case in point.

Tim wrote:

On Thu, 04 Nov 2004 13:25:33 +0000, Tim wrote:


After lots of helpful comments on my plight to redesign my Dad's CH
using a thermal store system, I was wondering if anyone could comment on
this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump assembly
by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents 70+C
water at the inflow end of the underfloor pipework.

So parts of the floor are presumably going to get rather hot???



OK - one adittional thing... I just found the installation manual on their
website and it does mention that the heating pipe must be run in a
double-spiral config, so a flow and return pipe are alway adjacent.

Wonder if that's how they make such a simple system work? ie they are
relying on the thermal conductivity of the screed to reduce the
inflow/outflow differential and also using the return flow to indrectly
cool the inflow... Sounds didgey - but it *could* just work?

Dream on Tim.

When I levelled my U/F heated floor prior to laying laminate, you could
see the wet bits betweenteh double spiral, and the dry bits above it.

The doble sopral simply spreads teh overall heating effect more or less
eenly across teh total floor area.

It does not stop localised hot spots on the floor surface, still less
inside it.

I think you are asking for a cracked screed.




Timbo

On Fri, 05 Nov 2004 14:27:51 +0000, The Natural Philosopher wrote:


Anything that isn't designed properly or controlled properly is going to
perform badly. You are a classic case in point.

I'm designed badly? As for control, you'll hav eto ask my wife :-/

Timbo

On Fri, 05 Nov 2004 14:17:49 +0000, The Natural Philosopher wrote:

Would you say my instincts are correct or would this type of regulation
actually work?


I think yiou have it right,.

Bite the bullet and use the proper system.

Ta muchly,

Timbo

Yeah, I think that considering I'm going to blow a wad on the conservatory
(have 2 bods in today to quote) I'll put the better system in just to be
safe.

Tim

On Fri, 05 Nov 2004 14:40:11 +0000, The Natural Philosopher wrote:

When I levelled my U/F heated floor prior to laying laminate, you could
see the wet bits betweenteh double spiral, and the dry bits above it.


That's certainly very interesting...

The doble sopral simply spreads teh overall heating effect more or less
eenly across teh total floor area.

It does not stop localised hot spots on the floor surface, still less
inside it.

I think you are asking for a cracked screed.


I guess it's one of those things - it either works OK forever or it
buggers your floor. I suspect that in many cases the Danfoss would work,
but I'm one of those unlucky sods that if it's going to pear up, it will
do it to me!

"Tim" wrote in message
news
On Thu, 04 Nov 2004 13:25:33 +0000, Tim wrote:

After lots of helpful comments on my plight to redesign my Dad's CH
using a thermal store system, I was wondering if anyone could comment on
this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump assembly
by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents 70+C
water at the inflow end of the underfloor pipework.

And so parts of the floor would overheat. This would be especially damaging
for a wooden floor.

Tim S wrote:

On Fri, 05 Nov 2004 14:27:51 +0000, The Natural Philosopher wrote:



Anything that isn't designed properly or controlled properly is going to
perform badly. You are a classic case in point.


I'm designed badly? As for control, you'll hav eto ask my wife :-/


IMM.

Timbo

G&M wrote:

"Tim" wrote in message
news
On Thu, 04 Nov 2004 13:25:33 +0000, Tim wrote:


After lots of helpful comments on my plight to redesign my Dad's CH
using a thermal store system, I was wondering if anyone could comment on
this underfloor heating component:

http://www.plumbworld.co.uk/186-0000

specifically: the "Return Temperature Controller"

It claims to be a way of avoiding a 4 port mixer + local pump assembly
by regulating the water return temperature.

The only thing I can see wrong is that it of course still presents 70+C
water at the inflow end of the underfloor pipework.


And so parts of the floor would overheat. This would be especially damaging
for a wooden floor.


Yes. I have a bit of a 'cold bridge' near one door threshold - no way to
avoid it really, and you can walk across teh floor in bare tootsies, and
know exactly where it is.

Screed is not a massicvely good heat conductor at all.

Iadeally you want zillions of tiny pipes all at 40C or so in it.
Practically a double helix or two with regulated flow temps is the best
solution.

Apart from the now sticking motorised valve, my system was dead easy to
install, and has after all the calcs and pressure tests etc, performed
exactly as it was supposed to.