Daisy chaining three radiators off a single trv
 

Hello and a joyous new year to one and all, I have a hopefully a very
quick and simple question.
Our kitchen has a small bay window that currently also houses a tiny
radiator that seems to be neither use nor ornament. I've taken
measurements and worked out that I can just fit three radiators into
the space, one along each edge of the bay but I doubt I can squeeze a
TRV onto each as well.
Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.

Thanks

Seri

Daisy chaining three radiators off a single trv
 

Seri wrote:

Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.


Yes, that's perfectly OK.


--
Grunff

Daisy chaining three radiators off a single trv
 

"Seri" wrote in message
ups.com...
Hello and a joyous new year to one and all, I have a hopefully a very
quick and simple question.
Our kitchen has a small bay window that currently also houses a tiny
radiator that seems to be neither use nor ornament. I've taken
measurements and worked out that I can just fit three radiators into
the space, one along each edge of the bay but I doubt I can squeeze a
TRV onto each as well.
Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.

Thanks

Seri



I've done this myself with 2 rads in a bay and it's worked fine for the ~4
years or so since fitted. The pipes between the rads simply form a "U" under
the floor with the valves full open. The TRV on the incoming supply and
valve on the output of the pair control them as "one".

Alan.



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Daisy chaining three radiators off a single trv
 

In article . com,
Seri writes
Hello and a joyous new year to one and all, I have a hopefully a very
quick and simple question.
Our kitchen has a small bay window that currently also houses a tiny
radiator that seems to be neither use nor ornament. I've taken
measurements and worked out that I can just fit three radiators into
the space, one along each edge of the bay but I doubt I can squeeze a
TRV onto each as well.
Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.

Weeeeel, yes & no . . . .

First rad will be too hot, last rad will be too cold, but baby bear . . . well,
you get the idea.

In your place I would try to do it with 2 rads instead of 3 and then tweak
the flow so that the overall drop between the 2 was 10 degrees. The
difference in mean radiator temps will so small as to cause little difference.
Even if the boiler is a condensing one, where the drop is meant to be
15-20degrees, having one small radiator pair set to 10 degree drop will not
screw up your system balance too much.

HTH
--
fred
Plusnet - I hope you like vanilla

Daisy chaining three radiators off a single trv
 

On Wed, 04 Jan 2006 12:27:47 -0800, Seri wrote:

Hello and a joyous new year to one and all, I have a hopefully a very
quick and simple question.
Our kitchen has a small bay window that currently also houses a tiny
radiator that seems to be neither use nor ornament. I've taken
measurements and worked out that I can just fit three radiators into
the space, one along each edge of the bay but I doubt I can squeeze a
TRV onto each as well.
Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.

I'd agree with the other posters that this will work, but there will be a
difference in temperature between the rads. Alternatively (and more
complicatedly) you could plum them in parallel - again with one TRV
controlling all 3. I've done this several times for pairs of rads in rooms
with pairs of windows, one rad under each window: not so much to save
money on the TRVs as to save the user having to adjust 2 TRVs at a time.

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Daisy chaining three radiators off a single trv
 

In article ,
John Stumbles writes:

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Works as one large radiator. That's how each section in
a single radiator is connected to the next, after all.

--
Andrew Gabriel

Daisy chaining three radiators off a single trv
 

On Wed, 04 Jan 2006 22:56:27 GMT, John Stumbles
wrote:

| On Wed, 04 Jan 2006 12:27:47 -0800, Seri wrote:
|
| Hello and a joyous new year to one and all, I have a hopefully a very
| quick and simple question.
| Our kitchen has a small bay window that currently also houses a tiny
| radiator that seems to be neither use nor ornament. I've taken
| measurements and worked out that I can just fit three radiators into
| the space, one along each edge of the bay but I doubt I can squeeze a
| TRV onto each as well.
| Is it feasible to fit a single TRV onto the first radiator and then
| simply daisy chain the other two from it to effectively make one large
| radiator?
|
| Any thoughts on why this would or wouldn't work would be extremely
| appreciated.
|
| I'd agree with the other posters that this will work, but there will bea
| difference in temperature between the rads. Alternatively (and more
| complicatedly) you could plum them in parallel - again with one TRV
| controlling all 3. I've done this several times for pairs of rads in rooms
| with pairs of windows, one rad under each window: not so much to save
| money on the TRVs as to save the user having to adjust 2 TRVs at a time.
|
| Incidentally where several rads have been trung together I've sometimes
| seen them connected at both top and bottom ports. Anyone got any theories
| on why this is done?

alternatively string all three onto a single pipe feed should even out
the temperatures. As they are small the hot water should get into
them OK


|-----| |------| |-------|
T | | | | | | radiators
R | | | | | |
V |-----| |------| |-------|
^ \/ ^ \/ ^ \/
--X----- ----- ----- ----- ------- ------ -----flow
--X----------------------------------------------

Hope you understand the ASCI ?art?



--
Dave Fawthrop dave hyphenologist co uk
17,000 free e-books at Project Gutenberg! http://www.gutenberg.net
For Yorkshire Dialect go to www.hyphenologist.co.uk/songs/

Daisy chaining three radiators off a single trv
 

On Wed, 04 Jan 2006 23:14:20 +0000, Andrew Gabriel wrote:

In article ,
John Stumbles writes:

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Works as one large radiator. That's how each section in
a single radiator is connected to the next, after all.

Well I suppose that gets to the point, though it doesn't really answer my
question. A single long rad with flow at one end and return at the other
will surely exhibit a similar temperature difference along its length (I
must test this when I get the 21374 I've just ordered from Toolstation :-))

However I can't see that joining multiple rads at top and bottom would
significantly change the heat distribution compared to connecting them
only at the bottoms (or, for that matter, at the tops).

Daisy chaining three radiators off a single trv
 

In article ,
John Stumbles writes:
On Wed, 04 Jan 2006 23:14:20 +0000, Andrew Gabriel wrote:

In article ,
John Stumbles writes:

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Works as one large radiator. That's how each section in
a single radiator is connected to the next, after all.

Well I suppose that gets to the point, though it doesn't really answer my
question. A single long rad with flow at one end and return at the other
will surely exhibit a similar temperature difference along its length (I
must test this when I get the 21374 I've just ordered from Toolstation :-))

However I can't see that joining multiple rads at top and bottom would
significantly change the heat distribution compared to connecting them
only at the bottoms (or, for that matter, at the tops).

I don't know the answer.
I might play devil's advocate to your suggestion, and suggest that
the whole length of the top will be at the boiler flow temperature
in a single radiator and multiples connected across top and bottom,
whereas in 3 radiators daisy-chained only along the bottom, this will
only apply to the first. OTOH, the first will be hotter down to the
bottom. I wonder if the first being hotter for a longer length can
compensate for the others being colder at the top and having less
capability to heat the air as it exits? This is likely to depend how
tall the radiators are, and how well they transfer their heat to the
passing air.

--
Andrew Gabriel

Daisy chaining three radiators off a single trv
 

The message
from John Stumbles contains these words:

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Works as one large radiator. That's how each section in
a single radiator is connected to the next, after all.

Well I suppose that gets to the point, though it doesn't really answer my
question. A single long rad with flow at one end and return at the other
will surely exhibit a similar temperature difference along its length (I
must test this when I get the 21374 I've just ordered from Toolstation :-))

However I can't see that joining multiple rads at top and bottom would
significantly change the heat distribution compared to connecting them
only at the bottoms (or, for that matter, at the tops).

The way I see it is that the method of connection does matter.

Taking the case of 3 radiators daisy chained at the bottom only first.

In each radiator the hot water would naturally rise to the top. As the
exit is at the bottom each would act like a normal radiator with the
proviso that the inlet temperature of each downstream radiator is the
exit temperature of the upstream radiator so the first radiator would
give out more heat than the second, et seq..

With the radiators daisy chained only at the top the situation is harder
to interpret, particularly what happens in the first radiator. That is
losing water to the next radiator only from the top so there is much
less heat available to be disapated but how much would be difficult to
quantify. The second radiator would have hot water flowing across the
top with the remainder of the radiator effectively dead and the third
radiator would get the largest proportion of the heat.

I think daisy chaining via both top and bottom connectors would
approximate to a normal radiator with the proviso that the restrictions
between the radiators might give a bigger temperature drop at the
junctions than would be expected had the top and bottom channels
continued with the same cross sectional area.

--
Roger Chapman

Daisy chaining three radiators off a single trv
 

"John Stumbles" wrote in message
.. .
On Wed, 04 Jan 2006 12:27:47 -0800, Seri wrote:

Hello and a joyous new year to one and all, I have a hopefully a very
quick and simple question.
Our kitchen has a small bay window that currently also houses a tiny
radiator that seems to be neither use nor ornament. I've taken
measurements and worked out that I can just fit three radiators into
the space, one along each edge of the bay but I doubt I can squeeze a
TRV onto each as well.
Is it feasible to fit a single TRV onto the first radiator and then
simply daisy chain the other two from it to effectively make one large
radiator?

Any thoughts on why this would or wouldn't work would be extremely
appreciated.

I'd agree with the other posters that this will work, but there will be a
difference in temperature between the rads. Alternatively (and more
complicatedly) you could plum them in parallel - again with one TRV
controlling all 3. I've done this several times for pairs of rads in rooms
with pairs of windows, one rad under each window: not so much to save
money on the TRVs as to save the user having to adjust 2 TRVs at a time.

Incidentally where several rads have been trung together I've sometimes
seen them connected at both top and bottom ports. Anyone got any theories
on why this is done?

Three rads. in at bottom on first. The centre is connected via the tops to
each either side and the return at the bottom of the last. It keeps the
temps along the three more even.

Daisy chaining three radiators off a single trv
 

On Fri, 6 Jan 2006 12:13:09 -0000, "Doctor Drivel"
wrote:


| Three rads. in at bottom on first. The centre is connected via the tops to
| each either side and the return at the bottom of the last. It keeps the
| temps along the three more even.

Oops! no connection to middle bottom.
--
Dave Fawthrop dave hyphenologist co uk
17,000 free e-books at Project Gutenberg! http://www.gutenberg.net
For Yorkshire Dialect go to www.hyphenologist.co.uk/songs/

Daisy chaining three radiators off a single trv
 

"Dave Fawthrop" wrote in message
...
On Fri, 6 Jan 2006 12:13:09 -0000, "Doctor Drivel"
wrote:


| Three rads. in at bottom on first. The centre is connected via the tops
to
| each either side and the return at the bottom of the last. It keeps the
| temps along the three more even.

Oops! no connection to middle bottom.

??

Daisy chaining three radiators off a single trv
 

The message ws.net
from "Doctor Drivel" contains these words:


| Three rads. in at bottom on first. The centre is connected via the tops
to
| each either side and the return at the bottom of the last. It keeps the
| temps along the three more even.

Oops! no connection to middle bottom.

??

In Dribbles fantasy world normal laws don't apply and the high level
outlet will discharge the cool water from the bottom of the middle
radiator.

--
Roger Chapman

Daisy chaining three radiators off a single trv
 

"Roger" wrote overt Chav Rogerness in message
k...
The message ws.net
from "Doctor Drivel" contains these words:


| Three rads. in at bottom on first. The centre is connected via the
tops
to
| each either side and the return at the bottom of the last. It keeps
the
| temps along the three more even.

Oops! no connection to middle bottom.

??

In

** snip drivel **

Roger your Chavness has got the better of you.

Daisy chaining three radiators off a single trv
 

Doctor Drivel wrote:
"Roger" wrote overt Chav Rogerness in
message k...
The message ws.net
from "Doctor Drivel" contains these words:


Three rads. in at bottom on first. The centre is connected via
the tops to
each either side and the return at the bottom of the last. It
keeps the temps along the three more even.

Oops! no connection to middle bottom.

??

In

** snip drivel **

Roger your Chavness has got the better of you.

What we're all trying to say (and I don't normally add to the
bash-the-Dribble competitions), is that the middle rad should have a
connection to the bottom.

Daisy chaining three radiators off a single trv
 

On Fri, 06 Jan 2006 11:18:25 +0000, Roger wrote:

The message
from John Stumbles contains these words:

....
... A single long rad with flow at one end and return at the other
will surely exhibit a similar temperature difference along its length (I
must test this when I get the 21374 I've just ordered from Toolstation :-))

However I can't see that joining multiple rads at top and bottom would
significantly change the heat distribution compared to connecting them
only at the bottoms (or, for that matter, at the tops).

The way I see it is that the method of connection does matter.
....
I think daisy chaining via both top and bottom connectors would
approximate to a normal radiator with the proviso that the restrictions
between the radiators might give a bigger temperature drop at the
junctions than would be expected had the top and bottom channels
continued with the same cross sectional area.

I agree with you now; and my 21374 does also: there seems little
temperature difference along the top of a rad so I think joining the rads
at the top as well as bottoms should tend to keep it that way.

Daisy chaining three radiators off a single trv
 

On Sat, 07 Jan 2006 00:28:46 GMT, in uk.d-i-y John Stumbles
wrote:

On Fri, 06 Jan 2006 11:18:25 +0000, Roger wrote:

The message
from John Stumbles contains these words:

...
... A single long rad with flow at one end and return at the other
will surely exhibit a similar temperature difference along its length (I
must test this when I get the 21374 I've just ordered from Toolstation :-))

However I can't see that joining multiple rads at top and bottom would
significantly change the heat distribution compared to connecting them
only at the bottoms (or, for that matter, at the tops).

The way I see it is that the method of connection does matter.
...
I think daisy chaining via both top and bottom connectors would
approximate to a normal radiator with the proviso that the restrictions
between the radiators might give a bigger temperature drop at the
junctions than would be expected had the top and bottom channels
continued with the same cross sectional area.

I agree with you now; and my 21374 does also: there seems little
temperature difference along the top of a rad so I think joining the rads
at the top as well as bottoms should tend to keep it that way.

Yeah, but what about that ugly pipe strung between them at the top? It
needs to run horizontally, not diving under the floor and back up again.
Better get permission from her-indoors first.

I think it best to best to bite the bullet and do them in parallel with
the pipework concealed beneath the floor (that's if you have an under
floor space). Whatever you do, don't fit a TRV to each radiator, it's a
virtually impossible to adjust them so that all the rads are equal
temperature, and an even greater pain to re-adjust them.

The difficulty is how to connect a single TRV to feed the string of 3
(or 2). I have done it using a chrome Tee fitted close to the TRV as per
the diagram below. You will need a 90 degree TRV that has 15mm
compression couplings at both its inlet and outlet. I found a suitable
Danfoss TRV for my system. You still need to balance each of the rads
using the lockshield valves, as normal.

X is TRV (1 off)
T is a compression Tee (preferably chrome)
V are Lockshield Valve (3 off)
+ are elbows or tees
= is horizontal, and | vertical 15mm pipe.


[select fixed pitch font to view the diagram properly]
_________ _________ _________
| | | | | |
| | | | | |
| | | | | |
TRV | | | | | |
X=T=|_________|V +=|_________|V +=|_________|V
| | | | | | |
in ==+ | +===============+===============+= out
| | |
+===============+===============+




Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
The Google uk.d-i-y archive is at http://tinyurl.com/65kwq
Remove NOSPAM from address to email me

Daisy chaining three radiators off a single trv
 

Thanks all for the replies and helpful advice. I fitted them this
weekend and expected the job to take a few hours. Started Saturday
morning, finished Sunday evening, typical of my DIY time scale
estimates.

Have to say that they actually all seem to heat up pretty evenly, even
though I only strung them together at the bottom (connection off from
22mm heating feed into the first rad, connection from that to the
second, connection from that to the third, connection from that to the
22mm heating return circuit) they all seem to heat up pretty quickly,
and the kitchen is now nice and toasty.

Anyway, thanks once again for the helpful replies.

Seri