If you were Registered and logged in, you could reply and use other advanced thread options
|
Posted by .p.jm on August 16, 2008, 9:43 am
On Sat, 16 Aug 2008 08:23:49 -0500, "Bob Shuman"
show/hide quoted text
>Sounds like you are describing something that is in every kitchen: a
>residential freezer.
No. It works primarily via convection. Even the old 'cold
plate' fan-less ones ( as slow as they were to cool ).
show/hide quoted text
> It too is very cold inside, but has "an extremely poor
>conductor of heat" (an insulator) on the outside "where it is most likely to
>come into contact" with any heat source.
>How well does the outside wall of that freezer collect the heat radiated
>from your body when you are a few feet or even a few inches away?
Once the heat is radiated from your body, it is gone ( to you
). It's not going to turn around and come back if it fails to find a
place to go.
Also, ;picture standing in front of a campfire - your face can
get too hot, while your ass freezes.
A very small percentaqe of the heat you radiate goes in any
one particular direction, and the amount that falls on the 'receiving
/ absorbing surface' will thusly decrease as the square of the
distance from it.
show/hide quoted text
>While I think that innovation starts with "outside the box" thinking, I
>believe that it still must be based on the laws of THIS universe.
Takes all the fun out of engineering .....
show/hide quoted text
> Bob
>> wrote:
>>> Not to mention such a system would instantly cause severe frostburn
>>> should
>>> any body parts come into contact with it.
>> Why would frostbite occur? The lowest layer [the one a body part would
>> most likely contact] is an extremely poor conductor of heat, so it
>> wouldn't feel that cold. It's the radiant cooling, that would feel
>> cold.
>>
--
Click here every day to feed an animal that needs you today !!!
www.theanimalrescuesite.com/
Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'
'With sufficient thrust, pigs fly just fine.'
HVAC/R program for Palm PDA's
Free demo online at www.pmilligan.net/palm/
Free 'People finder' program now at www.pmilligan.net/finder.htm
|
|
Posted by Stormin Mormon on August 7, 2008, 8:41 pm
Give it up, you fool. Cold doesn't radiate.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
Hi:
Please don't get upset at me. I posted something similar recently but
it didn't describe it properly.
I thinking of a cooling mechanism for houses and building in which the
cooling -- in the direct sense -- involves only radiation and no
convection at all. Sorta like a radiant-stove-top in reverse.
Indirectly, however, some amount of convection and conduction will be
needed [liquid helium, cold metals]. The cooling panel is the ceiling
and cools objects below it.
My visualization is that the radiant cooling panel contain extremely
cold metallic coils [cooled by liquid helium to almost absolute zero],
this would probably be deepest part of the panel.
http://en.wikipedia.org/wiki/Liquid_helium
Here, another question arises. Which is better to use -- Helium-3 or
Helium-4? Which one would have a stronger cooling effect if both were
at the same temperature?
The radiant cooling panel is the ceiling. It has 3 layers.
Layer 1: a material that allows heat radiation to pass through but is
a very poor conductor of heat
Layer 2: the same material found on the very top of radiant stove
tops
Layer 3: this is the deepest part containing the cool metallic coils.
Inside these coils are where the liquid helium would be flowing
through]
Layers 2 & 3 don't have any air molecules around them. The cold metal
coils are in a vacuum so they are not exposed to any air that would
solidify/liquefy. This means the space between layer 1 & 2 is also a
vacuum free of air.
There is dehumidification which is separate from the cooling.
Dehumidification is done by air processing devices on walls -- left,
right, back, front. These walls give out and take in air. There is
both re-circulation and fresh air. For fresh air, all vapors molecules
are let into the room -- excluding H20, CO2, gases with odors, toxic
vapors [such as CO], dust, irritating vapors, smoke or allergens. For
re-circulation, air in the room is sucked, cleaned [i.e. H20, CO2,
toxic vapors [such as CO], dust, irritating vapors, smoke and
allergens are removed] and then blown back into the room. In either
case, the amount of air-molecules-per-second-per-square-meter that is
sucked out of the room is the same is the amount of air-molecules-per-
second-per-square-meter the is blown into the room -- and visa versa.
Hence, the subject in the room doesn't feel any sucking or blowing.
The result is that the room now contains only N2 and O2 -- if you
exclude the CO2 and H2O-vapor emitted from the living subject[s]. The
N2 and O2 are kept at no less than least 70 degress Fahrenheit -- via
convection heating if the ambient temperature is less than 70 F -- to
prevent them from liquefying or solidifying. I know it's ironic that
the air would have to be heated in order to assist in preventing the
radiant cooler from failing. Still interesting, though.
Yes, heat absorbed into the radiant cooling panels is carried off
using convection -- but this is not what the subject inside the room
feels. The direct cooling effect on anything/anyone inside the room is
radiant.
Can anyone suggest a better manner for direct radiant cooling? If so,
please explain
By direct radiant cooling, I mean that if you place your body at a
noticeable distance from from panel, you'll feel cold because the
extreme cold of the coil will draw IR radiation away from your body.
OTOH, if you touch the panel, you won't feel as cold because the 1st
layer of the panel is a very poor conductor of heat.
On the ceiling, layer 1 is the lower than layer 2. Layer 3 is the
highest.
Thanks a bunch,
Radium
|
|
Posted by Green Xenon [Radium] on August 8, 2008, 3:06 am
On Aug 7, 5:41 pm, "Stormin Mormon"
show/hide quoted text
> Give it up, you fool. Cold doesn't radiate.
It doesn't but it can cool you by causing you to radiate heat towards
it. The radiant cooler is cold, the subject in the room under the
cooler is hot. Physics will attempt to equalize the temperature of the
two objects. If there is no conduction or convection between the two
objects, then the attempt will be facilitated by making the hotter
object emit thermal radiation toward the colder object. This is will
cool the hotter object. If you are the hotter object, you will feel
cold under the radiant cooler.
|
|
Posted by What a maroon on August 8, 2008, 9:02 am
On Fri, 8 Aug 2008 00:06:03 -0700 (PDT), "Green Xenon [Radium]"
show/hide quoted text
>On Aug 7, 5:41 pm, "Stormin Mormon"
>> Give it up, you fool. Cold doesn't radiate.
>It doesn't but it can cool you by causing you to radiate heat towards
>it. The radiant cooler is cold, the subject in the room under the
>cooler is hot. Physics will attempt to equalize the temperature of the
>two objects. If there is no conduction or convection between the two
>objects, then the attempt will be facilitated by making the hotter
>object emit thermal radiation toward the colder object. This is will
>cool the hotter object. If you are the hotter object, you will feel
>cold under the radiant cooler.
Well well, an idiot arguing with a dumbass. Someone pass the popcorn
please.
|
|
Posted by What a maroon on August 7, 2008, 11:36 pm
On Thu, 7 Aug 2008 15:53:27 -0700 (PDT), "Green Xenon [Radium]"
show/hide quoted text
>Hi:
Hi being the opertive word. You must be high to even want to try that.
What an asshat.
|
Page 4 of 6 < 1 2 3 > last >>
| Similar Threads | Posted | | Interested in adding remote indoor sensor to Honeywell visionPRO t'stat. | July 29, 2008, 10:43 pm |
| Convert a cooling thermostat to a cooling | September 29, 2006, 9:00 pm |
| upstiars cooling | August 1, 2006, 8:25 am |
| Window AC unit not cooling | August 1, 2006, 12:48 pm |
| Radiator use as a cooling coil | August 3, 2006, 11:24 pm |
| 13 SEER Splits not cooling!??! | August 8, 2006, 9:40 pm |
| datacenter cooling question.... | October 23, 2006, 3:45 pm |
| Wine Cooling Unit | December 28, 2006, 1:12 pm |
| HVAC Cooling Coil | July 13, 2007, 1:26 pm |
| Re: Adiabitic Cooling Maintenance | February 18, 2008, 1:15 pm |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap
>residential freezer.