Stone or Steel!

[begreen]

Radiant vs convection?

Physics tells us a warm surface at a lower temperature (165* F) emits RADIANT energy of LOWER AMPLITUDE than that of a hot surface (450* F). The effect of this, with time, is the lower surface temperature material warms objects and not the air (like rays from the sun on a cool spring day). The hotter the surface temperature, the higher the amplitude of the radiant energy which then strikes more molecules of air causing more CONVECTION heat (more indoor weather). The truth is most all stoves emit both radiant heat energy and cause convection heat as well.

Actually, just the opposite is true. Above 200ºF, the higher the temperature, the more heat is emitted as IR and the less natural convection occurs.

Amplitude in EM is a measure of the intensity of the field, not the wave "height". EM waves are not the same as matter waves (i.e. water, sound), and have no physical measurement (except in wavelength and frequency). Convection occurs because air molecules come into contact with the hot surface and become hotter through conduction from the hot material itself, not because radiant heat strikes the air molecules. In fact, air is fairly transparent to IR radiation, and so is a poor absorber of heat from that source.

For most radiant stoves operating at temps from 400º to 600º, about 30-35% of the heat is transferred via natural convection. At the lower temp range of masonry heaters (about 100ºF), 35% of heat transfer occurs happens through convection. These are not theoretical figures, they are experimentally derived measurements.

Please, don't take my word for it.

On Photon Wave Amplitude, and other:

"Because the particles in solids and liquids are relatively closely packed together they are very good at absorbing any radiant heat photons that happen to strike them. On the other hand gases, such as the air we breath, have enormous amounts of empty space between particles. As a result, the chance of photons hitting a gas particle is much smaller. The distance that a photon can travel through gas before striking a molecule is dependent on the amplitude of its wave motion. This amplitude will be greater (higher) in radiation from a hot object than in a cooler object. The greater the amplitude, the longer the path a photon "particle" will follow in order to cover a given distance through the gas and the greater the probability of encountering a gas molecule along that path.

Convective heat is an indirect form of heat transfer. The heat is not transferred directly, but rather indirectly through the medium of the air in the room which acts as the means of transport. The continual movement of air in a room heated by convection from a hot metal stove or a forced air system results in uncomfortable drafty conditions and uneven temperature zones. By contrast, in a room heated with a radiant heat the air remains still, eliminating uncomfortable drafts, with air temperature staying comfortably even. (my style change)"

Aye,
Marty

Say what they may, our convective stove heats our 2000 sq ft house very evenly. The quoted statement does not make it fact. Most forced air systems that are uncomfortably drafty are poorly installed HVAC systems. When I was doing this type work it was a common complaint, most often with adapted gravity ducted coal system that had the supplies and returns in the wrong locations. A well installed system should not feel drafty. FWIW, the radiant masonry heater convects a lot of heat too. It warms the air in the core of the house that travels in a loop across the ceiling and then cools and descends down the cooler outer walls of the house. That was the point of the article supplied:

"While anyone who has stood close to a house radiator in operation can attest to the direct and potent heat it gives off, steam heat also works in a secondary but important way. As hot air from the radiator rises, it displaces cold air above, which sinks and is warmed by radiator. This process of circulation is called convection.

 

[Battenkiller]

Please, don't take my word for it.

I ain't taking anybody's word for it... not unless they provide the equations that support it.

In the meantime, I woke up to a house that was 65º almost 24 hours after I had my last fire. Six additional hours later, it is now 67º in here (still no fire), aided immensely by my friend Mr. Sun, who sent light from his 10,000º surface 93 million miles to my planet, passed through hundreds of miles of atmosphere without warming it up, then through my solid glass windows without warming them up, then into my home, where they struck surfaces and finally gave up their light energy as heat, which warmed up the objects that were struck by that light, which are now radiating that heat back to other areas of the home but are having a real hard time passing back out through my IR opaque windows.

So all I can say is, I'm glad that the Photon Wave Amplitude Theory didn't prevent that from happening, because I'd be pretty chilly in here right now if it did. ;-)

 

[begreen]

Yep, the sun is a mighty good radiator. And without convection in the atmosphere, we would have a pretty uncomfortable and dry planet. We live in one large convection cycle stimulated by the radiation of the sun.

 

[Martin Strand III]

SNIP

But to answer your questions...

- Yes, to a large degree, IR does reflect off the surfaces in the room. Beyond a 30º incident angle, all EM radiation increasingly reflects off of surfaces to varying degrees, depending on the absorptivity/emissivity of the surface. In can either be reflected or absorbed, not much else can happen to it.

SNIP

A third possibility for radiant energy:

"Kirchhoff's law is really just common sense: When radiant energy hits any particular material it has to do one of three things:
1) Be absorbed (a perfect black body with emissivity of 1 absorbes all the radiant energy)
2) Be reflected (the opposite of a perfect black body - a material with low emissivity)
3) Pass through the material (transparancy)
The energy of the raditaion absorbed, reflected and transmitted through the material must equal the energy hitting the material." You can Google the formula if you enjoy looking at them.

Aye,
Marty

 

[DanCorcoran]

Anybody know how to pickle beets?

 

[Battenkiller]

Yep, the sun is a mighty good radiator. And without convection in the atmosphere, we would have a pretty uncomfortable and dry planet. We live in one large convection cycle stimulated by the radiation of the sun.

Well, I'm not trying to grow any corn or fill any rivers in my home, so I'll stick with radiant heat inside these four walls for now and feel all the warmer for it.

 

[Martin Strand III]

Please, don't take my word for it.

I ain't taking anybody's word for it... SNIP

So all I can say is, I'm glad that the Photon Wave Amplitude Theory didn't prevent that from happening, because I'd be pretty chilly in here right now if it did. ;-)

NO. NO. NO.

It's not the PWA Theory. It's back to Kirchhoff and the fact different substances have different properties of absorption, emissivity and transparency based on their molecular structure. Glass, the example you used for heat, once inside your house, does not pass back outside, is transparent in the visible wave length range of about half a micron but is opaque in the infrared wave length range of from one to two microns.

This is no more than a greenhouse effect. Nearly all the energy from the sun where the temperature is about 6,000 K, passes through the glass at a wave length of about one half micron but the heat re-radiated inside the greenhouse (your house) at room temperature of about 70 deg. F (we call 300 K radiation) emits radiation which peaks at about 9.6 microns, which glass does not transmit. Thus the emitted energy from the inside objects in a greenhouse does not get out.

Same thing happens in your car in the summer sun parked with the windows up. It's a real killer...

Aren't you the lucky one!

Aye,
Marty

 

[Battenkiller]

A third possibility for radiant energy:

"Kirchhoff's law is really just common sense: When radiant energy hits any particular material it has to do one of three things:
1) Be absorbed (a perfect black body with emissivity of 1 absorbes all the radiant energy)
2) Be reflected (the opposite of a perfect black body - a material with low emissivity)
3) Pass through the material (transparancy)
The energy of the raditaion absorbed, reflected and transmitted through the material must equal the energy hitting the material."

Yep. But we're not talking about just any radiant energy here, we're specifically talking about IR. It ain't passing through anything I have in here, at least that I am aware of.

As far as the formula for photon wave amplitude, I wouldn't even know how to search to find it. Everything I come up with talks about EM wave amplitude in terms of flux, or the actual numbers of photons striking a surface per unit of time, not their physical height (which I still maintain they have none). Each photon carries it's own specific "packet" of energy, each one travels at identical speeds in a vacuum, 100 photons of the same wavelength/frequency carry 100 times as much energy as 1 photon of the same wavelength. Beyond that, it is all mixing up classical and quantum concepts, and that really shouldn't be done.

 

[Battenkiller]

Aren't you the lucky one!

Seven south-facing windows.... wouldn't have it any other way. Every sunny day all the curtains get opened and the blinds raised. Right now, the sun has gotten low so I will go and close them all. Saves a lot of work/wood. :coolsmile:

 

[GAMMA RAY]

Hey BK, You took me back to instrumentation 1 and 2 in Nuclear Medicine school.....I haven't heard the words photons and wavelength in the same sentence since then..... about 13 years back.....brings back good memories. I got a 99 average in that class...studied my a#@ off but graduated in the top of my class...that's why I was the only graduate that bagged a full time job before I graduated. Sounds to me like you know what your talking about....but I am only a newbie here....so what I think probably does not count.

 

[Martin Strand III]

Aren't you the lucky one!

Seven south-facing windows.... wouldn't have it any other way. Every sunny day all the curtains get opened and the blinds raised. Right now, the sun has gotten low so I will go and close them all. Saves a lot of work/wood. :coolsmile:

Aren't you cold in the morning?

Burning wood all night isn't the safest thing to do just to wake up to a warm house.

My glass windows face east-south-east. Wouldn't have it any other way. No curtains to pull or catch dust. No blinds to open and close and catch dust. No oversized A/C to cool things down during those 'dog daze' of summer.

Aye,
Marty

 

[BrotherBart]

Anybody know how to pickle beets?

I think the first thing you do is boil some water to 6,000 C which is 10,000 F then open the curtains or something like that.

 

[DanCorcoran]

Thanks...that other stuff was making me nervous.

 

[begreen]

http://simplyrecipes.com/recipes/pickled_beets/

 

[GAMMA RAY]

I have used many recipes from simplyrecipes.com....................very good...........................
Try the lemon chicken one...

 

[begreen]

Yes, good thing I just had lunch or I'd be in the kitchen now cooking up something.

 

[NH_Wood]

Well, I'll just add........I really like my soapstone stove. Cheers!

 

[GAMMA RAY]

My favorite Dogfish head beer is infused with Belgian beet sugars so I guess I would like that recipe........Cheers to NH Wood!

 

[yooperdave]

Burning wood all night isn't the safest thing to do just to wake up to a warm house. -marty s

i disagree with that thought. burning wood all night is just as safe as all day, no? just saying that during the heating season, we are constantly building a fire and going to bed or even leaving the house for extended time. (work, shopping, visits, etc)

mark me down for steel

 

[Battenkiller]

Burning wood all night isn't the safest thing to do just to wake up to a warm house.

You're probably right about that, but after 25 years or so, at least it seems safe. :coolsmirk:

 

[Battenkiller]

Anybody know how to pickle beets?

I think the first thing you do is boil some water to 6,000 C which is 10,000 F then open the curtains or something like that.

Thanks. I really do have a crap load of beets from the garden that still haven't been processed.

Do I need a pressure cooker or do I just sit on the lid until they're done?

 

[BrotherBart]

Do I need a pressure cooker or do I just sit on the lid until they're done?

Sit on it BK. :coolgrin:

 

[pen]

here is my recipe for making pickled eggs / beets.

I use canned beets. You could substitute cooked / sliced fresh beets (just cook them right in the brine)

2 quart canning jars and lid
2-15ozcan sliced beets (or you can use ~ 4 cups of your own sliced beets)
14 hard boiled eggs
1 1/2 cups cider vinegar
1/2 cup white vinegar
2 tea pickling salt
1/4 tea black pepper
2 cloves garlic chopped
1 1/2 tea pickling spice
1/4 cup sugar
1 med onion sliced

Place 7 eggs in each jar
Bring everything except the eggs to a simmer.
Cover and let sit for 10 minutes w/ heat off
Bring back up to a simmer (if you boil it the beets will get too soft)
Divide hot beets / onions / brine over the eggs and immediately put lid on jars and place in the fridge.
Ready in 3 days

These will last for weeks in the fridge. Placing them in canning jars and "hot packing" them helps the pickling process work faster. They aren't officially canned so you can't keep them on the shelf but I wouldn't bat an eye at a month + refrigerated.

If there was a question about a wood stove in here I apologize, I missed it.

pen

 

[johnstra]

Somebody needs to do some research. Find out what the average number of responses is before a thread runs off in the weeds

I'm pleased this one ended up on something as useful as pickled beets. My 6 year old daughter loves them. I just showed this to her and it looks like we have a project for this weekend.

 

[begreen]

Stick with your big stone stove and be happy. It weighs the same as our big fellow. Mass rules.