Thermal fan

[Stelcom66]

I wonder how well those heat driven thermal fans work? Reviews I've read seem pretty good. Not necessarily the more expensive ones are rated higher. I currently have a 12v fan from an old telephone PBX running on 6v. That way it's quiet, but effective. Electricity costs will be going up big time here next month. The cost to run it is minimal, and I know the cost of the fan may never offset any electricity savings, but I like the 'green' concept of it.

 

[DAKSY]

Don't waste your money.

 

[Dan Freeman]

Blows some air around. Certainly not a strong breeze or anything like that. I have one on my stove. Sometimes I wonder if it is more a novelty more than anything else. You know, when guests come over who aren't wood-burners, and they are wide-eyed to see a fan working without any electricity.

 

[stoveliker]

I have one. It doesn't measurably spread heat in my 825 SQ ft or so basement beyond what it does without the fan.

However, my elderly neighbors saw my fan, and bought one. They put it on their small stove in their small, small home, and they are very happy, saying it helps a lot.

So, for small rooms it might help. For anything bigger it likely won't.

For me it's a toy gadget.

 

[Stelcom66]

Then maybe not worth the cost. My house isn't large, the stove is in the living room which is on the small side. Still, it would probably be less effective than what I have now.

 

[reaperman1]

I just put my Kill-o-watt meter on my woodstove blower to see how much juice it actually takes to run. The blower is variable speed on a rheostat. On high the fan draws about 45 watts, on the lowest speed its about 35 watts. When running my fan, I generally use the lowest speed. At 35 watts, it would take 28.5 hours to draw one kilowatt. Our cost per kilowatt is 13 cents, so the cost of running the fan for nearly 29 hours is only 13 cents.

 

[Stelcom66]

I just put my Kill-o-watt meter on my woodstove blower to see how much juice it actually takes to run. The blower is variable speed on a rheostat. On high the fan draws about 45 watts, on the lowest speed its about 35 watts. When running my fan, I generally use the lowest speed. At 35 watts, it would take 28.5 hours to draw one kilowatt. Our cost per kilowatt is 13 cents, so the cost of running the fan for nearly 29 hours on only 13 cents.

Thanks for the specs/results. My homemade fan setup would use even less.

 

[electrathon]

I have one. It is cute. Fun to watch. Moves almost no air. When it is really running hard, it won't blow out a match or even make significant movement of the flame. I use it more as a thermometer to see how hot the stove top is.

 

[Rearscreen]

I depend on mine to give me a visual of how hot the stove is running from afar.

 

[Stelcom66]

Then except for running (for what it's worth) during a power failure, it doesn't seem to be a valid option instead of an electrically powered fan.

 

[begreen]

Mostly they are a good visual indicator that moves a little bit of air. The original was by Caframo out of Canada. They still sell them and the quality is good. Now there are a host of imitators for as low as 1/4 the price coming from China. They also work, but not for the long haul. I had the original Caframo EcoFan running for almost 10 yrs before the motor bearings started to wear out due to loss of lubrication. Last year I tried a $49 VonHaus model from Amazon. The bearings are already starting to drag on it.

 

[Stelcom66]

Then that must be why I see a large range of prices. I've seen the related technology many years ago. My grandparents had an ornament that was placed close to and directly above one of the incandescent tree lights. (that was the only kind back then) There was a small blade that would spin from the heat.

 

[FPX Dude]

Why do these things move such little air, what is needed to make them effective?

 

[stoveliker]

Fan blade design, speed --> power. But that is limited because it generates its own.

 

[FPX Dude]

I replaced a WHF with a more efficient model, fan blades are better, crazy difference and much better even at low speeds. Whether this or ceiling fans, CFM is what matters, why doesn't someone MacGyver something more useful?

 

[stoveliker]

Because the power available from the thermoelectric element is limited. Can't drive an 18 wheeler on a 30 cc engine either.

 

[30WCF]

I’ve often thought if they had a solid shroud around them, they may move air more discernibly. Imagine it with a 12” tube. The blades are just in the back of the tube, and air was sucked in the back and forced out the front. It’s not moving fast enough to keep the air from just circling around it.
Mind you, I don’t have one and have only seen them In YouTube.

 

[begreen]

This thread stimulated me to do some more testing with the little VonHaus fan. It was giving a disappointing performance on the stovetop. It used to work on the trivet top of the T which would be around 300-350ºF, but this year it has been anemic, sometimes not starting up at all. Last night I opened up the trivet top and placed it right on the stovetop, at the very front. It started spinning merrily. More surprisingly, it was still spinning at 7:30 am when I went to load the stove with a stovetop of 250º. Not as fast, but still spinning.

Once the stove was up to 600º stove top temp I noticed that I could feel it blowing the hairs on my arm up to about 4 ft. away. Yes, rpms make a difference. I tried the candle test and it made the candle flame bend and flicker at 6 ft. and blew the flame out at 3 ft. Maybe this little fella has more pep than I was giving it credit for. We'll see how it stands up at the higher temps.

4 Blade Stove and Log Burner Fan

Give your stove or wood burner the boost it needs with a fire fan. It distributes heat around your room efficiently without needing electricity or batteries.

www.vonhaus.com

 

[stoveliker]

Be careful with too hot surfaces; the thermoelectric element has a maximum temperature it can withstand. Beyond that one might damage it.

My fan has a bimetal strip at the bottom that bends and moves the base of the fan off of the stove top of it gets above a certain temperature.

 

[begreen]

Be careful with too hot surfaces; the thermoelectric element has a maximum temperature it can withstand. Beyond that one might damage it.

My fan has a bimetal strip at the bottom that bends and moves the base of the fan off of the stove top of it gets above a certain temperature.

Yes, that was why I had it on the trivet top. To our old Ecofan's credit, it could deal with normal stovetop temps, even the 700º+ temps on the old 602. It was rated 212°F - 650°F. The VonHaus is rated up to 572ºF. This is why I put it at the front of the stovetop where it's about 100º cooler than the back. It used to start spinning around 150º but no more.

 

[Newbie78]

We bought an ecofan yesterday. The big one; 812 I think..

we put a small load on the fire just before we left for the city. 8 hours later we got home and placed the fan on the 150 degree stove top. Much to my delight, within about a minute or less it started to spin. I raked the coals, cracked the stove door, and got the coals hot as the fan started to spin faster. We got the rest of the groceries, etc into the house and then I put on a new load. After about 15 minutes the stove was warming up and the fan was starting to really go!

Now we could feel a substantial amount of air moving. Subtle, but substantial. Eventually I lit a bic lighter about a couple of feet in front of the fan. The flame was moving away from the fan. HARD. Somewhere within about 16" of the fan the flame was blown out. HARD!

this thing works very well by subtly moving air. This 812 model is rated at 175cfm max. I don't know how to measure that. I have it on a cooler part of the stove. It hasn't stopped spinning since a few minutes after it was placed on the stove.

about a half hour ago the morning reload had warmed the stove and I put the flame of a barbeque lighter in the fan's path. The bigger, weaker flame was extinguished at a greater distance and more forcefully even than the bic lighter.

I suppose there's a reason why nearly every stove in this cold climate has one of these things sitting on top of it. They work. Ours works very well, I'd say.

the naysayers are dead wrong, at least in the case of this model of ecofan..

 

[begreen]

I was looking at the large EcoFan yesterday. I may end up getting one when the VonHaus dies. I see now that one can buy replacement motors at a reasonable cost. Smart move. That's what died on our last ECO Fan after a decade of service, so I appreciate that it's now possible to keep it going if this happens.

 

[Newbie78]

I might just buy a replacement motor @20.00 cad.

obviously this company supports its product and doesn't expect buyers to put up the fairly high up-front cost ever again in their lifetime. Good attitude. Refreshing.

and it's canadian made.

for many, many years I bought Canadian, American, and German products as much as possible (mostly in that order). Sadly that is nearly impossible now.

so I'm always pleased when that consideration works out these days.

 

[Newbie78]

Oops! I guess it's 25.00 for a motor. I must've seen a usd price and mistook it.🤷‍♂️

 

[begreen]

Oops! I guess it's 25.00 for a motor. I must've seen a usd price and mistook it.🤷‍♂️

The smaller motor for the original 800 series fan is $20.