Does a Fan Produce More Heat or Just Blow the Air Around?

KLook · Post by **KLook** » Wed. Jan. 15, 2014 9:52 am

And your coal fire did not go out, and the CO did not come back in and asphyxiate you, and you did not have to increase air to increase burn rate, etc, etc. I know some are bored in the winter, but his one takes the cake. Good job Sunny.

Kevin

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 15, 2014 9:57 am

KLook wrote:And your coal fire did not go out, and the CO did not come back in and asphyxiate you, and you did not have to increase air to increase burn rate, etc, etc. I know some are bored in the winter, but his one takes the cake. Good job Sunny.

Kevin

Kevin thanks.
I should have added there were no changes to any of the damper settings, or adding coal. Just took readings, turned on the fan, waited and then took more readings in the exact same places.

And, even though the fan was moving air, after ten minutes I could feel that the room was warming up.
No wind-chill affect.

I'm going to leave the fan on for the rest of the day and see what happens.

Paul

Post by **Lightning** » Wed. Jan. 15, 2014 10:03 am

Sunny Boy wrote:After 15 minutes the two left hand stove top plates dropped in temp about 25 degrees. The stack temp went down about 3 degrees.

KLook wrote:The wall thermometer went from 72 to 75.

I couldn't help myself

Here is the proof of the marbles..
Less marbles up the chimney = more marbles are kept in the house..

Yes, Its really that simple...

Nice observations partner!!

SuperBeetle · Post by **SuperBeetle** » Wed. Jan. 15, 2014 10:08 am

Now finally something very simple that makes sense to me. Real world information not a theory. Nice job!

kstills · Post by **kstills** » Wed. Jan. 15, 2014 10:15 am

Sunny Boy wrote:Numbers and formulas are great, but as we techs say, "To prove it, ya gotta get to where the rubber meets the road".

Here's some quick test results. Make of them what you will.

I put a small table fan on the range's trivet pointing down over the firebox end of the stove.

I took I R gun readings at three location around the kitchen. Plus, a thermometer on a kitchen cabinet on an outside wall.

1. The gas stove top, nine feet away from the range. (a horizontal surface with a refrigerator blocking any radiation heat).
2. At chest height, on a kitchen cabinet door, 16 feet away at the opposite end of the kitchen (a vertical surface).
3. On the counter top below a window, 11 feet away ( A horizontal surface with cold air convection, from the window, moving across it).
4. The thermometer is at head height on the cabinet, above #3 and to the left of the window.

The day is cloudy and no wind.

I first took ten readings, a couple of seconds apart, at each point to get an average.

I then turned the fan on and after 15 minutes took more readings at these same points.

The pictures show the first readings on top with the fan off. The readings below are those with the fan on. Each time the IR gun was pointed at the area between the two arrows.

After 15 minutes the two left hand stove top plates dropped in temp about 25 degrees. The stack temp went down about 3 degrees.

The wall thermometer went from 72 to 75.

Paul

So this is evidence that you've changed the convection currents in the room ( I would surmise the air above the stove and behind the stove is now at a lower temperature than when you started)....and what else?

whistlenut · Post by **whistlenut** » Wed. Jan. 15, 2014 10:24 am

You guys have toooooooooooooooooo much free time!!! We need some REALLY cold weather to snap you out of this funk. ......depends is the safest answer......

freetown fred · Post by **freetown fred** » Wed. Jan. 15, 2014 10:31 am

Damn Doug, there ya go with that common sense nonsense again!

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 15, 2014 11:12 am

kstills wrote:
So this is evidence that you've changed the convection currents in the room ( I would surmise the air above the stove and behind the stove is now at a lower temperature than when you started)....and what else?

That, . . . or you can "surmise" that a .42 amp 6 inch fan, that is a little over 3 feet off the floor (stove top is 31 inches), and is pointing at only a slight angle downward, is actually removing heat from the stove top inches in front of it, rather than moving the heated air that is five feet above the fan. I would think you would "surmise" that by seeing that my test results also showed that the stove top temp dropped about 25 degrees in front of the fan. Or, are you just going to ignore that part ?

And, yes, it's a free country. You can surmise anything you want. You can also run your own tests and post your results for "peer review", instead of trying to discount others observations and tests.

Paul

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 15, 2014 11:15 am

whistlenut wrote:You guys have toooooooooooooooooo much free time!!! We need some REALLY cold weather to snap you out of this funk. ......depends is the safest answer......

Thanks, but I'll wait until I'm older to start wearing them !

Paul

freetown fred · Post by **freetown fred** » Wed. Jan. 15, 2014 11:16 am

Play nice girls, cold weather is a comin & you can actually play with the stoves instead of with one another.

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 15, 2014 11:18 am

freetown fred wrote:Play nice girls, cold weather is a comin & you can actually play with the stoves instead of with one another.

Yes, Daddy !

Paul

kstills · Post by **kstills** » Wed. Jan. 15, 2014 11:20 am

Sunny Boy wrote:
kstills wrote:
So this is evidence that you've changed the convection currents in the room ( I would surmise the air above the stove and behind the stove is now at a lower temperature than when you started)....and what else?
That, . . . or you can "surmise" that a .42 amp 6 inch fan, that is a little over 3 feet off the floor (stove top is 31 inches), and is pointing at only a slight angle downward, is actually removing heat from the stove top inches in front of it, rather than moving the heated air that is five feet above the fan. I would think you would "surmise" that by seeing that my test results also showed that the stove top temp dropped about 25 degrees in front of the fan. Or, are you just going to ignore that part ?

And, yes, it's a free country. You can surmise anything you want. You can also run your own tests and post your results for "peer review", instead of trying to discount others observations and tests.

Paul

What is the difference in btuh output between the starting temp of the stove and when it drops 25 Deg?

I get about 324 btuh less, while the stack is putting out about 20btuh less to the atmosphere.

Post by **franco b** » Wed. Jan. 15, 2014 11:43 am

Sunny Boy wrote:You can also run your own tests and post your results for "peer review",

You did a great job and deserve all the more credit because you already knew what the results would be yet took the time and trouble to get figures.

Trying to understand the science behind something almost always leads to an ever increasing multitude of factors to consider. Careful observation and experience often is all that's needed. I doubt if Ted Williams knew much about the science of hitting a baseball.

Mis-applying a law of science along with a lot of jargon just obfuscates the issue. I feel colder when the wind is blowing than when it is not.

Sunny Boy · Post by **Sunny Boy** » Wed. Jan. 15, 2014 11:59 am

kstills wrote:
What is the difference in btuh output between the starting temp of the stove and when it drops 25 Deg?

I get about 324 btuh less, while the stack is putting out about 20btuh less to the atmosphere.

The stove ? I have no idea. I didn't check the entire stove's surface area, or it's internal temps. However, the surface temp of the two plates directly in front of that small fan dropped, as I said, about 25 degrees.

Within fifteen minutes, the room was measurable warmer with just a small fan blowing across just that part of the top of the stove.

And, within a short time, the test points returned to the same non-fan temps when I shut the fan off to cook my lunch.

Now, . . . where's your test results ?

Paul

Horace · Post by **Horace** » Wed. Jan. 15, 2014 12:08 pm

But, what if you're using a barometric damper?

*Runs away*