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Majority of heat from a flame is convective -- not radiant -- that is why flames are hottest on top.

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Majority of heat from a flame is convective -- not radiant -- that is why flames are hottest on top. GreenXenon 05-07-2009
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Posted by GreenXenon on May 7, 2009, 1:37 pm
http://groups.google.com/group/alt.hvac/msg/c35e54a9a9a67836?hl=en :






> >>


> >> On Aug 9, 8:02 pm, .p.jm@see_my_sig_for_address.com wrote in
> >> >http://groups.google.com/group/alt.hvac/msg/9646d0d0d4cfa110?hl=en:


> >> >> Think of this - stand next to a campfire on a cold night. up
> >> >> close = toasty warm. 10 feet away = cold.


> >> > The overwhelming majority of heat emitted from a fire, is convective
> >> > heat, not radiant heat. There is some radiant heat but it is very
> >> > small compared to the convective heat.


> >> WRONG!!!!!!


> > Convection is what causes the fire to point upwards. Hot air travels
> > up via convection. Put your hand below or on the side of a flaming
> > candle, you won't feel much heat [esp. below the below the flame].
> > However, if you place your hand above the candle, you get a painful
> > amount of heat. This is because most of the flame emits heat via
> > convection. Only a trace amount of the fire's heat is emitted through
> > radiation.


> Well I am not to argue with you, however any benefits that you are getting
> from fire is radiant heat


Fire consists of hot gases that move upwards. If it were radiant heat,
then the heat would not specifically move away from the source of
gravity. If you aim a butane torch downward, most of the heat will
still go up. If it were radiant heat, then it heat from the torch
would move downward.


> what ever goes up it is waste and yes it is
> definitely hot strait above of it however I would not call it convection
> heat.


What mechanism other than convection would cause the heat to go upward
as opposed to in all directions?


> Convection heat is consider your base board water or electric as long
> you don't have forced air over but natural convection.


Huh? "base board water or electric"??

Posted by GreenXenon on May 7, 2009, 8:48 pm




> >http://groups.google.com/group/alt.hvac/msg/c35e54a9a9a67836?hl=en:


> >>




> >> >>


> >> >> On Aug 9, 8:02 pm, .p.jm@see_my_sig_for_address.com wrote in
> >> >> >http://groups.google.com/group/alt.hvac/msg/9646d0d0d4cfa110?hl=en:


> >> >> >> Think of this - stand next to a campfire on a cold night. up
> >> >> >> close = toasty warm. 10 feet away = cold.


> >> >> > The overwhelming majority of heat emitted from a fire, is convective
> >> >> > heat, not radiant heat. There is some radiant heat but it is very
> >> >> > small compared to the convective heat.


> >> >> WRONG!!!!!!


> >> > Convection is what causes the fire to point upwards. Hot air travels
> >> > up via convection. Put your hand below or on the side of a flaming
> >> > candle, you won't feel much heat [esp. below the below the flame].
> >> > However, if you place your hand above the candle, you get a painful
> >> > amount of heat. This is because most of the flame emits heat via
> >> > convection. Only a trace amount of the fire's heat is emitted through
> >> > radiation.


> >> Well I am not to argue with you, however any benefits that you are getting
> >> from fire is radiant heat


> > Fire consists of hot gases that move upwards. If it were radiant heat,
> > then the heat would not specifically move away from the source of
> > gravity. If you aim a butane torch downward, most of the heat will
> > still go up. If it were radiant heat, then it heat from the torch
> > would move downward.


> >> what ever goes up it is waste and yes it is
> >> definitely hot strait above of it however I would not call it convection
> >> heat.


> > What mechanism other than convection would cause the heat to go upward
> > as opposed to in all directions?


> WHAT MECHANISAM KEEPS EART SPINNIG FROM WEST TO EAST?????

I don't know. What is it?

In the original message you were stating that most of a flame's heat
is radiant. How can that be when most of the heat of a flame goes up?

Thermal radiation does not favor any direction, is simply travels from
hot to cold. Convection, OTOH, causes hot gases to rise and cold gases
to sink. This is why a flame's heat goes up. It's convective heat in
action.

Only in micro/zero-gravity is the majority of the flame's heat
transfer through radiation.

Posted by Patriot on May 7, 2009, 11:49 pm
GreenXenon wrote:
>
>
>
>
>>> http://groups.google.com/group/alt.hvac/msg/c35e54a9a9a67836?hl=en:
>
>
>>>>
>
>
>
>
>>>>>>
>
>
>>>>>> On Aug 9, 8:02 pm, .p.jm@see_my_sig_for_address.com wrote in
>>>>>>> http://groups.google.com/group/alt.hvac/msg/9646d0d0d4cfa110?hl=en:
>
>
>>>>>>>> Think of this - stand next to a campfire on a cold night. up
>>>>>>>> close = toasty warm. 10 feet away = cold.
>
>
>>>>>>> The overwhelming majority of heat emitted from a fire, is convective
>>>>>>> heat, not radiant heat. There is some radiant heat but it is very
>>>>>>> small compared to the convective heat.
>
>
>>>>>> WRONG!!!!!!
>
>
>>>>> Convection is what causes the fire to point upwards. Hot air travels
>>>>> up via convection. Put your hand below or on the side of a flaming
>>>>> candle, you won't feel much heat [esp. below the below the flame].
>>>>> However, if you place your hand above the candle, you get a painful
>>>>> amount of heat. This is because most of the flame emits heat via
>>>>> convection. Only a trace amount of the fire's heat is emitted through
>>>>> radiation.
>
>
>>>> Well I am not to argue with you, however any benefits that you are getting
>>>> from fire is radiant heat
>
>
>>> Fire consists of hot gases that move upwards. If it were radiant heat,
>>> then the heat would not specifically move away from the source of
>>> gravity. If you aim a butane torch downward, most of the heat will
>>> still go up. If it were radiant heat, then it heat from the torch
>>> would move downward.
>
>
>>>> what ever goes up it is waste and yes it is
>>>> definitely hot strait above of it however I would not call it convection
>>>> heat.
>
>
>>> What mechanism other than convection would cause the heat to go upward
>>> as opposed to in all directions?
>
>
>> WHAT MECHANISAM KEEPS EART SPINNIG FROM WEST TO EAST?????
>
> I don't know. What is it?

The Kings pet Gerbils.
>
> In the original message you were stating that most of a flame's heat
> is radiant. How can that be when most of the heat of a flame goes up?
>
> Thermal radiation does not favor any direction, is simply travels from
> hot to cold. Convection, OTOH, causes hot gases to rise and cold gases
> to sink. This is why a flame's heat goes up. It's convective heat in
> action.
>
> Only in micro/zero-gravity is the majority of the flame's heat
> transfer through radiation.

Posted by on May 7, 2009, 11:58 pm


>>>> What mechanism other than convection would cause the heat to go upward
>>>> as opposed to in all directions?
>>
>>
>>> WHAT MECHANISAM KEEPS EART SPINNIG FROM WEST TO EAST?????
>>
>> I don't know. What is it?
>The Kings pet Gerbils.
>>

        Bullshit !

        It's my minions, I tell you !!!!!!


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Posted by geothermaljones on May 7, 2009, 11:24 pm
Everyone knows, Heat rises...
That's why when you snuff out your Cigar in the palm of your hand, it
doesn't hurt... Here, hold this piece of charcoal...

Anyone ever see Lawrence of Arabia?
He could hold a burning match in his fingers until it went out.
He had some "I don't give a damn" attitude about it, but since heat rises,
we all know he was a girly man, it didn't hurt a bit...

Heat seeks cold in all directions... That's why you insulate below radiant
floors.
Earth averages 55dF & your floor is 80dF...? heat rises right? I don't need
that insulation!!!
Of course, if I sell LPG, Electricity, or NG, I might not be sold on that
hot/cold theory...

goodluck
geothermaljones


> http://groups.google.com/group/alt.hvac/msg/c35e54a9a9a67836?hl=en :
>>
>> >>
>> >> On Aug 9, 8:02 pm, .p.jm@see_my_sig_for_address.com wrote in
>> >> >http://groups.google.com/group/alt.hvac/msg/9646d0d0d4cfa110?hl=en:
>> >> >> Think of this - stand next to a campfire on a cold night. up
>> >> >> close = toasty warm. 10 feet away = cold.
>> >> > The overwhelming majority of heat emitted from a fire, is convective
>> >> > heat, not radiant heat. There is some radiant heat but it is very
>> >> > small compared to the convective heat.
>> >> WRONG!!!!!!
>> > Convection is what causes the fire to point upwards. Hot air travels
>> > up via convection. Put your hand below or on the side of a flaming
>> > candle, you won't feel much heat [esp. below the below the flame].
>> > However, if you place your hand above the candle, you get a painful
>> > amount of heat. This is because most of the flame emits heat via
>> > convection. Only a trace amount of the fire's heat is emitted through
>> > radiation.
>> Well I am not to argue with you, however any benefits that you are
>> getting
>> from fire is radiant heat
> Fire consists of hot gases that move upwards. If it were radiant heat,
> then the heat would not specifically move away from the source of
> gravity. If you aim a butane torch downward, most of the heat will
> still go up. If it were radiant heat, then it heat from the torch
> would move downward.
>> what ever goes up it is waste and yes it is
>> definitely hot strait above of it however I would not call it convection
>> heat.
> What mechanism other than convection would cause the heat to go upward
> as opposed to in all directions?
>> Convection heat is consider your base board water or electric as long
>> you don't have forced air over but natural convection.
> Huh? "base board water or electric"??



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