balancing rads - return hotter than feed?
 

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

Any advice greatly received as always.

balancing rads - return hotter than feed?
 

new to diy wrote:
Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)?

I'll buy that rad off you!


Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

The majority of valves these days are not sensitive to the direction of
flow, and as such you can fit them either side. The system will still
work fine.


--
Grunff

balancing rads - return hotter than feed?
 

Grunff wrote:
new to diy wrote:
Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)?

I'll buy that rad off you!

If those are your CH temps in the middle of winter, I think you've got
bigger problems than not understanding that water cools when it flows
through a rad.


NT

balancing rads - return hotter than feed?
 

In an earlier contribution to this discussion,
new to diy wrote:

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

Any advice greatly received as always.

A radiator can't *heat* the water - unless it's got an electric heater
inside it! So what you *think* are flow and return are actually the other
way round.

In what units are you measuring the temperature? I don't know of *any*
measurement units in which a number in the 20's would be a sensible reading
for a radiator! Or maybe you're pointing your IT thermometer at the *wall*?
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

balancing rads - return hotter than feed?
 

In article .com,
new to diy wrote:
I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

If you're measuring pipe temperatures in the 20C range, try switching the
heating on?

--
*The man who fell into an upholstery machine is fully recovered.*

Dave Plowman London SW
To e-mail, change noise into sound.

balancing rads - return hotter than feed?
 

Grunff wrote:
new to diy wrote:
Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)?

I'll buy that rad off you!


Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

The majority of valves these days are not sensitive to the direction of
flow, and as such you can fit them either side. The system will still
work fine.


--
Grunff

IR thermometers are the work of the devil. They are *very* difficult
to use and even in the hands of an expert can often give misleading
results.

Firstly, apply some common sense. Touch the radiator, does it *feel*
like it's 20C? (That's room ambient for most rooms).

Next calibrate the meter. The instructions to do should have been
supplied and you will require an object of known temperature and with
the same characteristics in the IR range as your radiator. TBH it's
probably easier to measure the temperature of the radiator with a
proper thermometer then use that to calibrate the IR meter!

Finally return it to the shop.

balancing rads - return hotter than feed?
 

In an earlier contribution to this discussion,
Calvin wrote:


IR thermometers are the work of the devil. They are *very* difficult
to use and even in the hands of an expert can often give misleading
results.

That is cobblers! They give very quick - and reasonably accurate - readings,
which is what you need when you are checking a *lot* of radiators in quick
succession. If you stick a little square of black tape on each bottom corner
of each radiator - right next to the input/output connections - you can get
very consistent results. The readings don't need to be accurate to a
fraction of a degree because you are measuring the *relative* temperature
drop across a number of radiators. This is by far the quickest way to do it.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

balancing rads - return hotter than feed?
 

Set Square wrote:
In what units are you measuring the temperature? I don't know of *any*
measurement units in which a number in the 20's would be a sensible reading
for a radiator! Or maybe you're pointing your IT thermometer at the *wall*?

It's probably a PPPro IR thermometer and he's pointing it where the
laser is pointing ;-)

MBQ

balancing rads - return hotter than feed?
 

TBH it's probably easier to measure the temperature of the radiator
with a proper thermometer then use that to calibrate the IR meter!

Completely disagree with you, I'm afraid. IR thermometers are far more
accurate, reliable and, most importantly, rapid than any conventional one,
provided you understand how they work and how varying emmissivity effects
readings.

You only have to use ones that measure human temperature to realise that an
IR gives clearly an accurate reading, whilst a non-IR one invariably
underreads. I have built an IR thermometer from scratch 10 years ago at
university and understand how they work.

To get accurate results on metal pipes, it is advisable to reduce the
reflectivity of the surface, and just as importantly provide a fixed
emissivity for comparison. This is easiest done by applying some black tape
and aiming at that.

Conventional thermometers are a faff and complete waste of time.

Christian.

balancing rads - return hotter than feed?
 

On Fri, 27 Jan 2006 14:49:04 -0000, "Christian McArdle"
wrote:

TBH it's probably easier to measure the temperature of the radiator
with a proper thermometer then use that to calibrate the IR meter!

Completely disagree with you, I'm afraid. IR thermometers are far more
accurate, reliable and, most importantly, rapid than any conventional one,
provided you understand how they work and how varying emmissivity effects
readings.

You only have to use ones that measure human temperature to realise that an
IR gives clearly an accurate reading, whilst a non-IR one invariably
underreads. I have built an IR thermometer from scratch 10 years ago at
university and understand how they work.

To get accurate results on metal pipes, it is advisable to reduce the
reflectivity of the surface, and just as importantly provide a fixed
emissivity for comparison. This is easiest done by applying some black tape
and aiming at that.

Conventional thermometers are a faff and complete waste of time.

Christian.



Yes and no.

If you use a surface probe thermocouple with shield connected to a
proper meter then the results are very good.

e.g.

http://www.tmelectronics.co.uk/hheldsur.html


I measured against an IR thermometer on a radiator and the two
correlated to within half a degree.

However, one would need to spend £100 or so for a reasonable meter,
themocouple adaptor and probe.


--

..andy

balancing rads - return hotter than feed?
 

Set Square wrote:
In an earlier contribution to this discussion,
Calvin wrote:


IR thermometers are the work of the devil. They are *very* difficult
to use and even in the hands of an expert can often give misleading
results.

That is cobblers! They give very quick - and reasonably accurate - readings,
which is what you need when you are checking a *lot* of radiators in quick
succession. If you stick a little square of black tape on each bottom corner
of each radiator - right next to the input/output connections - you can get
very consistent results. The readings don't need to be accurate to a
fraction of a degree because you are measuring the *relative* temperature
drop across a number of radiators. This is by far the quickest way to do it.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Sorry, I'm in a bit of a bad mood today and my previous post was a
little simplistic. Allow me to explain...

IR thermometers measure IR radiation and from that infer the
temperature of the object. Which is great if other significant
variables are controlled but all too often they are not and as it's
(non-visible) IR we're talking about generally the user isn't even
aware the variables exist.

In the case of a home user measuring radiators in a number of rooms the
result is going to altered by the surface finish of the radiator: one
that is matt black (or with your black sticky tape on it) will tend to
give a more sensible reading than one which is highly reflective to IR.
Indeed, depending on the size of the measuring spot on the meter, one
which is highly reflective to IR might even give a very different
reading as the meter is moved so that it points to a different part of
the "fold" of the surface.

The ambient IR will probably also be different from room to room and
will change the results although for the task of radiator balancing it
shouldn't change the differential.

My job sporadically involves worrying about how hot various bits of
electronics get during operation. Usually when things have already
gone wrong and we're looking for a cause. An IR profile of a PCB can
help but it can also mislead you if you don't understand what can
effect the readings. (IR measured temperature of the case of that
polished-top IC - that'll be the temperature of the ceiling then sir).

As for the OPs situation I wonder if he's using the sort of meter which
re-calibrates each time you press the ON button and then shows a live
reading as you move it around. If it is one of those then he's
probably just listed the temperature delta between some random
floor/wall/whereever-he-was-pointing-it-at when he pressed the button
and the radiator itself. The common sense rule still applies: if it
feels hot it certainly isn't 20-something C.

balancing rads - return hotter than feed?
 

On 27 Jan 2006 02:12:38 -0800, in uk.d-i-y "new to diy"
wrote:

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

Any advice greatly received as always.

1 Read the balancing FAQ if you haven't already
http://www.diyfaq.org.uk/plumbing/rad-balance.html

2 Apply a black tape patch as suggested by others and take readings off
that. Ignore the laser spot and put the IR thermometer sensor close to
the black tape, say 2 or 3 inches away. Wave the thermometer around a
little and look for a maximum reading, which will be when it is truly
pointing at the black patch.

3 As the rad warms up, the flow end gets hot first.

4 Your figures of 16 to 27 make no sense. A hot radiator should be well
over 50 degrees Celsius, possibly up to almost 80C.

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

balancing rads - return hotter than feed?
 

new to diy wrote

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

They have obviously fitted a cooler by mistake instead of a radiator.

You should ask for it to be exchanged at once.
--

mike

balancing rads - return hotter than feed?
 

Calvin wrote



IR thermometers are the work of the devil. They are *very*
difficult to use and even in the hands of an expert can often give
misleading results.

That is cobblers! They give very quick - and reasonably accurate -
readings, which is what you need when you are checking a *lot* of
radiators in quick succession.


Sorry, I'm in a bit of a bad mood today and my previous post was a
little simplistic. Allow me to explain...

I still agree with Set Square. Each rad you check will generally be of the
same material and finish at each end. We are less interested in the actual
temperature than the drop, so a lot of the problems you describe don't
matter.

And from personal experience, I can get my system more or less balanced
easily, before I had the IR I wasn't in with a prayer.

--

mike

balancing rads - return hotter than feed?
 

On Fri, 27 Jan 2006 20:11:34 +0000, Phil Addison wrote:

On 27 Jan 2006 02:12:38 -0800, in uk.d-i-y "new to diy"
wrote:



4 Your figures of 16 to 27 make no sense. A hot radiator should be well
over 50 degrees Celsius, possibly up to almost 80C.


I was about to suggest that the heating has to be switched on during nthe
process ?!?


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

balancing rads - return hotter than feed?
 

On Fri, 27 Jan 2006 05:27:42 -0800, Calvin wrote:


Grunff wrote:
new to diy wrote:
Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)?

I'll buy that rad off you!


Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

The majority of valves these days are not sensitive to the direction of
flow, and as such you can fit them either side. The system will still
work fine.


--
Grunff

IR thermometers are the work of the devil. They are *very* difficult
to use and even in the hands of an expert can often give misleading
results.

Firstly, apply some common sense. Touch the radiator, does it *feel*
like it's 20C? (That's room ambient for most rooms).

Next calibrate the meter. The instructions to do should have been
supplied and you will require an object of known temperature and with
the same characteristics in the IR range as your radiator. TBH it's
probably easier to measure the temperature of the radiator with a
proper thermometer then use that to calibrate the IR meter!

IR units work fine just done try measure any shiny pipes - painted rads
give good results (colour and finish not significant IME).


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

balancing rads - return hotter than feed?
 

"Christian McArdle" wrote in message
.. .
TBH it's probably easier to measure the temperature of the radiator
with a proper thermometer then use that to calibrate the IR meter!

Completely disagree with you, I'm afraid. IR thermometers are far more
accurate, reliable and, most importantly, rapid than any conventional one,
provided you understand how they work and how varying emmissivity effects
readings.

You only have to use ones that measure human temperature to realise that
an
IR gives clearly an accurate reading, whilst a non-IR one invariably
underreads. I have built an IR thermometer from scratch 10 years ago at
university and understand how they work.

To get accurate results on metal pipes, it is advisable to reduce the
reflectivity of the surface, and just as importantly provide a fixed
emissivity for comparison. This is easiest done by applying some black
tape
and aiming at that.

Conventional thermometers are a faff and complete waste of time.

Christian.

Maplin sold one for £30. Who else sells them?

balancing rads - return hotter than feed?
 

On Fri, 27 Jan 2006 22:36:31 GMT, wrote:

On 27 Jan,
Andy Hall wrote:

On Fri, 27 Jan 2006 14:49:04 -0000, "Christian McArdle"
wrote:

[snip good stuff, I totally agree.]


Yes and no.

If you use a surface probe thermocouple with shield connected to a
proper meter then the results are very good.

e.g.

http://www.tmelectronics.co.uk/hheldsur.html


I measured against an IR thermometer on a radiator and the two
correlated to within half a degree.

However, one would need to spend £100 or so for a reasonable meter,
themocouple adaptor and probe.

I would definitely go the IR method, it gives an accurate enough readout in a
couple of seconds for each radiator. By the time the thermocouple stabilises
you could have checked several radiators with an IR thermometer.

I agree with you that an IR thermometer is suitable for radiator
balancing. However, the shielded ribbon type of themocouple
stabilises in under a second.

Even I can't get around radiators that quickly :-)



It also showed up some cold spots in my walls and ceilings in a scan lasting
seconds rather than hours. I now have to get round to sorting out the deficit
of insulation.

--

..andy

balancing rads - return hotter than feed?
 

new to diy wrote:

Ok, I've just bought an IR thermometer with laser guide (IR89 -
awesome) and have began balance my rads in earnest.

I have a choice of 2 rads which could be considered closest to the
bolier. One rad has a 4 degrees C drop across it (20-16) but the
other, get this, has an increase across it (21-27)? Have the builders
put the wheelhead/lockshield valves on the wrong way round? Would the
central heating system still work ok if this were the case?

Any advice greatly received as always.

Like all tools, an IR thermometer needs to be used properly.

I found that mine gave inconsistant results, even though I used black
tape as a target.

Then when I looked more logically, I discovered that there was a
parallax problem where at close distances, the laser target wasn't the
same spot that the IR was reading. The dot might be on the pipe, but the
IR is pointing at the wall behind the pipe.

If yours allows continuous readings while the trigger is pressed, try
holding it sideways and scanning across a hot pipe. On mine ( Maplins
£30 ) at a range of a couple of inches, the temperature reaches a peak
reading when the laser dot has passed the pipe and is shining on the
wall.

I now scan across a small target and look for the peak. It's much more
reliable.