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Default Radiator reflective foil

Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268

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On 14/12/2011 13:49, Moonraker wrote:
Does it lose its effectiveness if emulsioned over? This one, though


Of course.

It has to be a mirror surface to be "not a black body" at thermal
wavelengths. Same way that thin metallic coating is used on survival
blankets to get maximum reduction in heat loss for minimum weight.

The way it works to stop heat loss is by being a mirror surface
reflector - and preferably backed with 3-5mm of expanded polystyrene to
insulate it from the cold wall as well. Both play their part here.

expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268

Interesting aluminium foil that is magnetic. Ovepriced junk. If you
stick it onto the radiator itself you reduce the convective heat output.

The best buy at the moment are the roughly 60cm square sheets for foil
backed with 5mm of polystyrene in B&Q/Wickes. They mount onto the wall.
See the previous thread for details.

Regards,
Martin Brown
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In article , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www..co.uk/product_info.php/products_id/268

This absolutely stinks of false review/mention spam but benefit of the
doubt given:

The only stuff like this that works is foil with a thin layer of
insulation backing that is stuck to or otherwise fitted very close to
the wall. It works by reflecting radiated heat and providing a little
insulation where it is most needed. Painting it will remove any
radiation reflecting benefit.

Attaching bare foil of any flavour directly to the radiator, as proposed
on the linked site, is a total waste of time and is highly likely to
reduce the heat output from the radiator.

Given the apparent misinformation presented on the linked site I would
recommend avoiding it..
--
fred
it's a ba-na-na . . . .
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Default Radiator reflective foil

On Dec 14, 1:49*pm, Moonraker wrote:
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please


No. Radiators convect, they dont radiate, and a shiny metal surface
makes no difference to convection or conduction. Its a waste of
kitchen foil.


NT
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Default Radiator reflective foil

On 14/12/2011 15:04, fred wrote:
In article , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www..co.uk/product_info.php/products_id/268


On balance it looks like a greensploitation site to me.

This absolutely stinks of false review/mention spam but benefit of the
doubt given:

The only stuff like this that works is foil with a thin layer of
insulation backing that is stuck to or otherwise fitted very close to
the wall. It works by reflecting radiated heat and providing a little
insulation where it is most needed. Painting it will remove any
radiation reflecting benefit.

Attaching bare foil of any flavour directly to the radiator, as proposed
on the linked site, is a total waste of time and is highly likely to
reduce the heat output from the radiator.

Given the apparent misinformation presented on the linked site I would
recommend avoiding it..


I'll second that.

Regards,
Martin Brown



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Default Radiator reflective foil

In message , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268

I always thought that heat-reflecting foil went on the wall behind the
radiator. However, as this type is held in position with magnetic tape,
presumably it goes on the metal of the radiator itself.

As its wall-side surface is shiny, this should reduce the radiator's
radiation in the direction of the wall. As its radiator-side will also
be shiny, this will reflect heat back into the radiator.

As presumably it won't be seen, why would you even want to emulsion over
it?

As matter of principle, yes, anything which reduces the reflectivity of
a radiating (or an absorbing surface) will reduce its effectiveness in
radiating/absorbing heat. However, it could be argued that the thickness
of the paint reduces the heat conduction to/from a metal surface of the
paint.
--
Ian

--- Posted via news://freenews.netfront.net/ - Complaints to ---
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Default Radiator reflective foil

On 14/12/2011 15:06, NT wrote:
On Dec 14, 1:49 pm, wrote:
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please


No. Radiators convect, they dont radiate, and a shiny metal surface
makes no difference to convection or conduction. Its a waste of
kitchen foil.


Actually it makes a fair bit of difference once the temperature of the
radiator is above 50C or so. Convection is still dominant but you can
also feel the thermal radiation in front of most decent radiators.

Reflecting that away from *outer* walls is worthwhile, but far better
with insulation behind so the foil is thermally isolated.

I have seen someone get caught out by an old style linear regulator PSU
they put in a basic folded shiny aluminium case and it got so hot that
it went into thermal shutdown. After painting it black it was 60C.

(in fact any non metallic colour would do as "Black" for thermal IR)

Regards,
Martin Brown
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Default Radiator reflective foil

On Dec 14, 3:43*pm, Martin Brown
wrote:
On 14/12/2011 15:06, NT wrote:

On Dec 14, 1:49 pm, *wrote:
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please


No. Radiators convect, they dont radiate, and a shiny metal surface
makes no difference to convection or conduction. Its a waste of
kitchen foil.


Actually it makes a fair bit of difference once the temperature of the
radiator is above 50C or so. Convection is still dominant but you can
also feel the thermal radiation in front of most decent radiators.

Reflecting that away from *outer* walls is worthwhile, but far better
with insulation behind so the foil is thermally isolated.

I have seen someone get caught out by an old style linear regulator PSU
they put in a basic folded shiny aluminium case and it got so hot that
it went into thermal shutdown. After painting it black it was 60C.

(in fact any non metallic colour would do as "Black" for thermal IR)

Regards,
Martin Brown


Everything above abolute zero temperature (minus 273.15degC) radiates
energy. if you have two adjacent objects at different temperatures,
they radiate energy at one another until they equalise. Assuming
energy is not being added to them).
The shiney foil delays the process.
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Default Radiator reflective foil

On 14/12/2011 15:21, Ian Jackson wrote:
In message , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268

I always thought that heat-reflecting foil went on the wall behind the
radiator. However, as this type is held in position with magnetic tape,
presumably it goes on the metal of the radiator itself.

As its wall-side surface is shiny, this should reduce the radiator's
radiation in the direction of the wall. As its radiator-side will also
be shiny, this will reflect heat back into the radiator.

As presumably it won't be seen, why would you even want to emulsion over
it?

As matter of principle, yes, anything which reduces the reflectivity of
a radiating (or an absorbing surface) will reduce its effectiveness in
radiating/absorbing heat. However, it could be argued that the thickness
of the paint reduces the heat conduction to/from a metal surface of the
paint.

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!

--
Residing on low ground in North Staffordshire
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Default Radiator reflective foil

On Dec 15, 9:56*am, harry wrote:
On Dec 14, 3:43*pm, Martin Brown
wrote:



On 14/12/2011 15:06, NT wrote:


On Dec 14, 1:49 pm, *wrote:
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please


No. Radiators convect, they dont radiate, and a shiny metal surface
makes no difference to convection or conduction. Its a waste of
kitchen foil.


Actually it makes a fair bit of difference once the temperature of the
radiator is above 50C or so. Convection is still dominant but you can
also feel the thermal radiation in front of most decent radiators.


Reflecting that away from *outer* walls is worthwhile, but far better
with insulation behind so the foil is thermally isolated.


I have seen someone get caught out by an old style linear regulator PSU
they put in a basic folded shiny aluminium case and it got so hot that
it went into thermal shutdown. After painting it black it was 60C.


(in fact any non metallic colour would do as "Black" for thermal IR)


Regards,
Martin Brown


Everything above abolute zero temperature (minus 273.15degC) radiates
energy. if you have two adjacent objects at different temperatures,
they radiate energy at one another until they equalise. Assuming
energy is not being added to them).
The shiney foil delays the process.


Yes, everything radiates, the question is how much. Radiators don't
radiate to a significant extent, meaning the conducted heat output is
very much greater. What's wanted to cut heat loss is insulation, not a
reflector.


NT


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Default Radiator reflective foil

On Dec 15, 10:13*am, Moonraker wrote:
On 14/12/2011 15:21, Ian Jackson wrote:

In message , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268


I always thought that heat-reflecting foil went on the wall behind the
radiator. However, as this type is held in position with magnetic tape,
presumably it goes on the metal of the radiator itself.


As its wall-side surface is shiny, this should reduce the radiator's
radiation in the direction of the wall. As its radiator-side will also
be shiny, this will reflect heat back into the radiator.


As presumably it won't be seen, why would you even want to emulsion over
it?


As matter of principle, yes, anything which reduces the reflectivity of
a radiating (or an absorbing surface) will reduce its effectiveness in
radiating/absorbing heat. However, it could be argued that the thickness
of the paint reduces the heat conduction to/from a metal surface of the
paint.


Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!


I think you'll find tesco and sainsburys far cheaper.


NT
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Default Radiator reflective foil

On Dec 14, 3:43*pm, Martin Brown
wrote:
On 14/12/2011 15:06, NT wrote:

On Dec 14, 1:49 pm, *wrote:
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please


No. Radiators convect, they dont radiate, and a shiny metal surface
makes no difference to convection or conduction. Its a waste of
kitchen foil.


Actually it makes a fair bit of difference once the temperature of the
radiator is above 50C or so. Convection is still dominant but you can
also feel the thermal radiation in front of most decent radiators.

Reflecting that away from *outer* walls is worthwhile, but far better
with insulation behind so the foil is thermally isolated.

I have seen someone get caught out by an old style linear regulator PSU
they put in a basic folded shiny aluminium case and it got so hot that
it went into thermal shutdown. After painting it black it was 60C.



So, in fact, the best colour to paint radiators is black, not the
conventional white.

Robert

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"RobertL" wrote in message
...


So, in fact, the best colour to paint radiators is black, not the
conventional white.


You have to be careful, just because its black doesn't mean it behaves as a
black body.

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On 15/12/2011 11:21, RobertL wrote:
On Dec 14, 3:43 pm, Martin
wrote:

Reflecting that away from *outer* walls is worthwhile, but far better
with insulation behind so the foil is thermally isolated.

I have seen someone get caught out by an old style linear regulator PSU
they put in a basic folded shiny aluminium case and it got so hot that
it went into thermal shutdown. After painting it black it was60C.


So, in fact, the best colour to paint radiators is black, not the
conventional white.


The difference is extremely marginal.

The visible light colour bears no relation to the thermal IR properties.
Almost *any* colour of paint that is not mirror finish metallic radiates
like a black body at the sort of thermal IR wavelengths characteristic
of the Earths ambient temperature.

Tactically if you want to keep a building cool painting it brilliant
white is the optimum. This was done of observatory domes until quite
recently when modern aircon became preferred and the domes are now
painted with a very sophisticated semi metallic off white paint system
that has neutral heat loss properties under a clear night sky.

The old stuff used to radiate too well leading to cold air currents
spilling over the edge of the dome slit and turbulence.

Regards,
Martin Brown
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On Thu, 15 Dec 2011 10:13:52 +0000, Moonraker wrote:

On 14/12/2011 15:21, Ian Jackson wrote:
In message , Moonraker
writes
Does it lose its effectiveness if emulsioned over? This one, though
expensive looks ideal, any experience here please?
http://www.greenstamp.co.uk/product_...roducts_id/268

I always thought that heat-reflecting foil went on the wall behind the
radiator. However, as this type is held in position with magnetic tape,
presumably it goes on the metal of the radiator itself.

As its wall-side surface is shiny, this should reduce the radiator's
radiation in the direction of the wall. As its radiator-side will also
be shiny, this will reflect heat back into the radiator.

As presumably it won't be seen, why would you even want to emulsion over
it?

As matter of principle, yes, anything which reduces the reflectivity of
a radiating (or an absorbing surface) will reduce its effectiveness in
radiating/absorbing heat. However, it could be argued that the thickness
of the paint reduces the heat conduction to/from a metal surface of the
paint.

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!


http://www.toolstation.com/shop/Cons.../sd2738/p26805

Needs a good adhesive and time to dry.
--
Peter.
The gods will stay away
whilst religions hold sway


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In article , PeterC
writes
On Thu, 15 Dec 2011 10:13:52 +0000, Moonraker wrote:

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!


http://www.toolstation.com/shop/Cons...on/Radiator%20
Foil/d210/sd2738/p26805

or just http://www.toolstation.com/shop/p26805 , the middle bit is
redundant.

I'm not sure that that one has an insulated backing which in my view is
the only one worth using.

Needs a good adhesive and time to dry.


Strong wallpaper paste perhaps with a dob of pva sounds good.
--
fred
it's a ba-na-na . . . .
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On Thu, 15 Dec 2011 19:56:12 +0000, fred wrote:

In article , PeterC
writes
On Thu, 15 Dec 2011 10:13:52 +0000, Moonraker wrote:

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!


http://www.toolstation.com/shop/Cons...on/Radiator%20
Foil/d210/sd2738/p26805

or just http://www.toolstation.com/shop/p26805 , the middle bit is
redundant.

Yes, sorry - Dialog has an anti-wrap feature so I tend to be lazy and use
that.

I'm not sure that that one has an insulated backing which in my view is
the only one worth using.


It has a thin layer of PE(?) foam on the back.

Needs a good adhesive and time to dry.


Strong wallpaper paste perhaps with a dob of pva sounds good.


TS does a strong adhesive that I used. The foil is still on after about 18
months.
--
Peter.
The gods will stay away
whilst religions hold sway
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In article , PeterC
writes
On Thu, 15 Dec 2011 19:56:12 +0000, fred wrote:

In article , PeterC
writes
On Thu, 15 Dec 2011 10:13:52 +0000, Moonraker wrote:

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!

http://www.toolstation.com/shop/Cons...ation/Radiator

%20
Foil/d210/sd2738/p26805

or just http://www.toolstation.com/shop/p26805 , the middle bit is
redundant.

Yes, sorry - Dialog has an anti-wrap feature so I tend to be lazy and use
that.

Poor wording by me I'm afraid, just meant to point out how toolstation
links _can_ be shortened if you chose to rather than you _should_ have.

I'm not sure that that one has an insulated backing which in my view is
the only one worth using.


It has a thin layer of PE(?) foam on the back.

Excellent, I had considered recommending it to the o/p first time round
but it wasn't clear on the TS description or photo (TS's main weakness
IMV).

Needs a good adhesive and time to dry.


Strong wallpaper paste perhaps with a dob of pva sounds good.


TS does a strong adhesive that I used. The foil is still on after about 18
months.

--
fred
it's a ba-na-na . . . .
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On Thu, 15 Dec 2011 21:57:40 +0000, fred wrote:

It has a thin layer of PE(?) foam on the back.

Excellent, I had considered recommending it to the o/p first time round
but it wasn't clear on the TS description or photo (TS's main weakness
IMV).


If going to collect it, a simple check is to squeeze the packet - it should
be a bit resilient (if the assistant complains, squeeze the rad. foil
instead).
--
Peter.
The gods will stay away
whilst religions hold sway
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On 15/12/2011 20:34, PeterC wrote:
On Thu, 15 Dec 2011 19:56:12 +0000, fred wrote:

In , PeterC
writes
On Thu, 15 Dec 2011 10:13:52 +0000, Moonraker wrote:

Thanks for all the help, the general opinion is that the magnetic stuff
a rip off but it is worth using reflective foil, so I will send my
daughter to B&Q or Wickes for some, as it for her house!

http://www.toolstation.com/shop/Cons...on/Radiator%20
Foil/d210/sd2738/p26805

or just http://www.toolstation.com/shop/p26805 , the middle bit is
redundant.

Yes, sorry - Dialog has an anti-wrap feature so I tend to be lazy and use
that.

I'm not sure that that one has an insulated backing which in my view is
the only one worth using.


It has a thin layer of PE(?) foam on the back.


I wouldn't consider using anything in this application where the backing
was thin enough to allow it to be sold in rolls or folded like that. The
best I have seen is 3mm and 5mm thick polystyrene foam with foil backing
available in 600mm square and nearly rigid. It will snap if handled
badly and is easily cut to shape with a craft knife.

It is always a compromise between obstructing airflow and minimising
loss through the wall. The rigid stuff is a lot easier to work with too
as it is naturally flat and doesn't want to curl up and can be attached
with a few dabs of decent PVA or wallpaper paste on the back.

B&Q/Wickes have a decent version of it. (Not in rolls)

Regards,
Martin Brown



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On Fri, 16 Dec 2011 08:19:39 +0000
PeterC wrote:

On Thu, 15 Dec 2011 21:57:40 +0000, fred wrote:

It has a thin layer of PE(?) foam on the back.

Excellent, I had considered recommending it to the o/p first time
round but it wasn't clear on the TS description or photo (TS's main
weakness IMV).


If going to collect it, a simple check is to squeeze the packet - it
should be a bit resilient (if the assistant complains, squeeze the
rad. foil instead).


What assistant?
--
Davey.
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On Fri, 16 Dec 2011 23:54:58 +0000, Davey wrote:

On Fri, 16 Dec 2011 08:19:39 +0000
PeterC wrote:

On Thu, 15 Dec 2011 21:57:40 +0000, fred wrote:

It has a thin layer of PE(?) foam on the back.

Excellent, I had considered recommending it to the o/p first time
round but it wasn't clear on the TS description or photo (TS's main
weakness IMV).


If going to collect it, a simple check is to squeeze the packet - it
should be a bit resilient (if the assistant complains, squeeze the
rad. foil instead).


What assistant?


The people in my local TS are friendly and helpful - willing to get items to
look at (TS' site is woefully lacking in information).
--
Peter.
The gods will stay away
whilst religions hold sway
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