In article , "Ed Pawlowski" wrote:

"Shawn Hirn" wrote in message

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

Maybe not. If you put a barrier over the top of the heat, it won't go up.
Heat can radiate down, just as the sun does. I'd still rather have it in
the floor, but ceilings can work.

Remember in a apartment, there is a floor then a ceiling, then a floor, then a ceiling,,,,
There is no real insulation between apartments.

"GregS" wrote in message
...
In article , "Ed Pawlowski"
wrote:

"Shawn Hirn" wrote in message

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

Maybe not. If you put a barrier over the top of the heat, it won't go up.
Heat can radiate down, just as the sun does. I'd still rather have it in
the floor, but ceilings can work.

Remember in a apartment, there is a floor then a ceiling, then a floor,
then a ceiling,,,,
There is no real insulation between apartments.

Do you know that for sure? It may have been in the original installation.
Unless we can see it, we don't know what is there do we? Could be a
reflective barrier.

In article , "Ed Pawlowski" wrote:

"GregS" wrote in message
...
In article , "Ed Pawlowski"
wrote:

"Shawn Hirn" wrote in message

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

Maybe not. If you put a barrier over the top of the heat, it won't go up.
Heat can radiate down, just as the sun does. I'd still rather have it in
the floor, but ceilings can work.

Remember in a apartment, there is a floor then a ceiling, then a floor,
then a ceiling,,,,
There is no real insulation between apartments.

Do you know that for sure? It may have been in the original installation.
Unless we can see it, we don't know what is there do we? Could be a
reflective barrier.


I don't think the OP elaborated. Even if there is a reflective barrier, heat
will still flow up.

I said earlier, if the celing is expected to heat a room, its going to be too
hot to touch.

greg

Ed Pawlowski wrote:

Heat can radiate down, just as the sun does.

Is there an up and down in space? The sun is round and radiates in all
different directions because of its shape.

On Thu, 15 Jan 2009 11:02:27 -0500, "badgolferman"
wrote:

Ed Pawlowski wrote:

Heat can radiate down, just as the sun does.

Is there an up and down in space? The sun is round and radiates in all
different directions because of its shape.
It seems to me that what is often called radiant heat isn't radiation
at all. The heating elements do radiate to the nearby building
materials (the floor) and then the heat is conducted through the floor
to your feet and shoes as well as nearby air. The heat is then spread
around the room via convection. In other words, using the sun's
radiation as an example isn't very helpful to someone wanting to
install radiant heat in their apartment.

The floor is much better than the ceiling because heating your feet
makes you feel warm at a lower air temp.

"GregS" wrote in message
I said earlier, if the celing is expected to heat a room, its going to be
too
hot to touch.

greg

Not true

If you add radiant ceiling panels they operate at about 150 degrees. BUT,
if you use an imbedded system, the same amount of heat energy is spread over
a much larger area and operating temperatures are MUCH lower. It is typical
to run at less than 100° and use 25W panels.

On Jan 15, 11:02*am, "badgolferman"
wrote:
Ed Pawlowski wrote:
Heat can radiate down, just as the sun does.

Is there an up and down in space? *The sun is round and radiates in all
different directions because of its shape.

given the sun's gravity, it's radiating up.

On Jan 15, 11:26*am, wrote:
On Thu, 15 Jan 2009 11:02:27 -0500, "badgolferman"

wrote:
Ed Pawlowski wrote:

Heat can radiate down, just as the sun does.

Is there an up and down in space? *The sun is round and radiates in all
different directions because of its shape.

It seems to me that what is often called radiant heat isn't radiation
at all. *The heating elements do radiate to the nearby building
materials (the floor) and then the heat is conducted through the floor
to your feet and shoes as well as nearby air. *The heat is then spread
around the room via convection. *In other words, using the sun's
radiation as an example isn't very helpful to someone wanting to
install radiant heat in their apartment. *

The floor is much better than the ceiling because heating your feet
makes you feel warm at a lower air temp.

yeah, for either the floor or the ceiling to do much radiating, it
would have to be red hot. it's convecting.

friend of mine had a house built with "radiant heating" in the ceiling
decades ago, state of the art whenever it was built. they hated it.
didn't heat well, and it made the ceiling plasterboard or whatever it
was crack a lot. they said there was just that one brief period when
people were installing it, they stopped pretty quick when it turned
out to be a dud.

On Jan 9, 11:59*am, Richard Fangnail
wrote:
What are the pros and cons of having radiant heat in your ceiling? *My
apt. building has it in the ceiling and I'm not sure how well it
works. *I was looking through webpages and the radiant heat systems
were all in the floors.

well, the pros are probably not installing it any more, which means
the guys selling it are cons.

In article , z wrote:
yeah, for either the floor or the ceiling to do much radiating, it
would have to be red hot. it's convecting.

False. For an object to radiate heat, it needs only to be warmer than its
surroundings.

friend of mine had a house built with "radiant heating" in the ceiling
decades ago, state of the art whenever it was built. they hated it.
didn't heat well, and it made the ceiling plasterboard or whatever it
was crack a lot. they said there was just that one brief period when
people were installing it, they stopped pretty quick when it turned
out to be a dud.

One incompetent installation invalidates the entire principle, huh?

On Jan 15, 12:58*am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!

terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!

Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

--
aem sends...

On Sun, 18 Jan 2009 14:08:03 GMT, aemeijers wrote:

terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!

Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I had it in an apartment thirty or so years ago. You're right it was
horrible. AND expensive, even then. I now have forced "cold air
heat" (heat pump) and am not too impressed with it either. My last
house had gas-fired hot water baseboard, which was nice.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

"Tiny tube ducts"? If you're wanting to cool the slab, bad idea. I
don't like cold feet.

krw wrote:
On Sun, 18 Jan 2009 14:08:03 GMT, aemeijers wrote:

terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.
No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!
Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I had it in an apartment thirty or so years ago. You're right it was
horrible. AND expensive, even then. I now have forced "cold air
heat" (heat pump) and am not too impressed with it either. My last
house had gas-fired hot water baseboard, which was nice.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

"Tiny tube ducts"? If you're wanting to cool the slab, bad idea. I
don't like cold feet.
No, the tiny (high pressure) tube ducts run through the ceiling to
corners of the rooms. Same house as had the radiant heat, and same thing
they do for people that want AC in a boiler'n'radiator house. Slabs stay
cool from ground contact anyway. (Not that I would ever build a slab
house, but that is a different rant for another time.)

--
aem sends....

On Jan 18, 1:52*am, z wrote:


yeah, i'm over here warming myself on the radiant heat from my cat
across the room.


If you can see it, you are.

Your body is radiating heat at all times. So is the cat's. Whether
there is a net flow from you to the cat, or from the cat to you,
depends largely on the temperature difference. (Also somewhat on
color and geometry.) The calculation includes the 4th power of the
temperature differences, by the way.

This is basic physics, and the fact that you don't believe it doesn't
invalidate it. It can be calculated, it can be measured.

On Sun, 18 Jan 2009 17:20:25 GMT, aemeijers wrote:

krw wrote:
On Sun, 18 Jan 2009 14:08:03 GMT, aemeijers wrote:

terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.
No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!
Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I had it in an apartment thirty or so years ago. You're right it was
horrible. AND expensive, even then. I now have forced "cold air
heat" (heat pump) and am not too impressed with it either. My last
house had gas-fired hot water baseboard, which was nice.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

"Tiny tube ducts"? If you're wanting to cool the slab, bad idea. I
don't like cold feet.
No, the tiny (high pressure) tube ducts run through the ceiling to
corners of the rooms. Same house as had the radiant heat, and same thing
they do for people that want AC in a boiler'n'radiator house.

Oh, those aren't what I consider "tiny" (perhaps 6-8"). When I lifed
in VT we had "window" units, through the wall. It wasn't hot enough
and there weren't enough hot days to justify central AC.

Slabs stay
cool from ground contact anyway. (Not that I would ever build a slab
house, but that is a different rant for another time.)

That's very true. Unfortunately there was little choice in my current
house. Slabs are the norm, which ruled out basements also.
Fortunately the ground never gets cold enough to make the floors
unbearable, even the tile.

On Jan 18, 2:48*pm, TimR wrote:
On Jan 18, 1:52*am, z wrote:



yeah, i'm over here warming myself on the radiant heat from my cat
across the room.

If you can see it, you are.

Your body is radiating heat at all times. *So is the cat's. *Whether
there is a net flow from you to the cat, or from the cat to you,
depends largely on the temperature difference. *(Also somewhat on
color and geometry.) *The calculation includes the 4th power of the
temperature differences, by the way.

This is basic physics, and the fact that you don't believe it doesn't
invalidate it. *It can be calculated, it can be measured.

ok, you and cjt are hereby banned from bidding on any contracts for
HVAC at my house.

z wrote:

On Jan 18, 2:48 pm, TimR wrote:

On Jan 18, 1:52 am, z wrote:




yeah, i'm over here warming myself on the radiant heat from my cat
across the room.

If you can see it, you are.

Your body is radiating heat at all times. So is the cat's. Whether
there is a net flow from you to the cat, or from the cat to you,
depends largely on the temperature difference. (Also somewhat on
color and geometry.) The calculation includes the 4th power of the
temperature differences, by the way.

This is basic physics, and the fact that you don't believe it doesn't
invalidate it. It can be calculated, it can be measured.


ok, you and cjt are hereby banned from bidding on any contracts for
HVAC at my house.

Fine. I wouldn't want to bid on a house heated by cat radiation,
anyway.

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form .

"aemeijers" ...
..................The heat had shadows.


Well put.

On Jan 18, 11:34*pm, CJT wrote:
Fine. *I wouldn't want to bid on a house heated by cat radiation,
anyway.


those hairless ones are damn warm, though.

In article , aemeijers wrote:
terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!

Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

The radiation is useless because you need air circulation in this case.
That kind of defeets the purpose of the hot ceiling.

greg

On Tue, 20 Jan 2009 14:10:00 GMT, (GregS)
wrote:

In article , aemeijers wrote:
terry wrote:
On Jan 15, 12:58 am, Shawn Hirn wrote:

Heat rises, so placing the radiant heating elements in the ceiling makes
no sense. What that does is heat the space above the ceiling.

No. Incorrect. Warm 'air' rises.

'Radiant' heat will pass through and then warm the surface of almost
anything it then strikes.

For example the radiated heat of the sun arrives at the earth's
surface! Even through the almost complete vacuum of space. It them
warms anything it can shine on and can cause sunburn! No matter if you
are 'up North' or 'down' in Australia!

Also if you pt your hand below a hot light bulb one can feel radiated
warmth.

One can hold a soldering iron above ones hand and 'feel' the heat
below!

Also those bowl type electric heaters (and heat lamps) radiate heat in
any direction, up, down, sideways, they wouldn't be much use if they
did not. You don't have to stand on top of them to feel their warmth;
sometimes they are mounted pointing 'down' in bathrooms.

Radiant heaters also sometimes mounted in ceilings of swimming pool
buildings shining down. Have also seen ceiling mounted radiant heaters
in the loading area of a commercial building and the floor some twelve
feet below was damp and steaming!

Forget it, some of the people in this thread will never understand. Like
I posted a week or so ago, I used to hang out in a house that had that
ceiling radiant heat. Top half of the room felt fine, but stick your
legs under the kitchen table (which I did on a regular basis, mooch that
I am), and your legs were cold. If the house was sealed up for several
hours, with nobody walking around stirring up the air, there was a
definite layering of air temps. The ceiling heat was an infrared
flashlight, basically. A wide, non-glowing version of a pool or garage
heater. I can see why people quit installing it, especially at current
power costs. I'd never use it.

I'm old fashioned- I like gas forced air heat. If I was building a
McMansion with lots of tiled showoff areas, I might also consider floor
radiant heat, since I hate wearing shoes inside. (But then you also have
to install a separate system of tiny tube ducts for the AC.)

The radiation is useless because you need air circulation in this case.
That kind of defeets the purpose of the hot ceiling.

As has been point out before, defeets get cold too.