Stove top fans, why you need one!

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(James Higginson) #1


We have a wood burning stove in our house and it provides the only source of heat for the 200 square meter space. It’s a good one, it’s heavy and burns well and it can stay in overnight. We do not, however, have any means of circulating the heat it generates; it simply rises and disperses mainly to the upper floors meaning that the bedrooms up there are generally warmer than the living spaces below, i.e. the wrong way around.

I did temporarily install a fan within the chimney enclosure which enabled me to transfer some of the heat to another room. This is the basis of a popular method of heat transference. It worked well although it was a bit noisy. So when I heard about stove fans (via an earlier post on SFN) I was intrigued.

Stove fans sit on top of your wood burner and are powered by a small thermoelectric generator, this requires no mains power or battery; they are completely autonomous and even vary their speed according to the the heat produced by your stove.

Positioning is important, they must draw cooler air from behind to function correctly. For this reason they must be placed at the rear of the stove. One thing you need to be aware of is that they have an upper temperature limit, there is a bimetallic strip on the underside and if they get too hot this will lift the base up slightly to reduce the temperature of the fan. This failsafe will only protect the device up to a point, if your stove pipe reaches 345 degrees Celsius they should be removed to avoid permanent damage. According to my stove pipe thermometer, 345 degrees is way too hot for efficient operation anyway, so under normal circumstances there is no need to touch it.

So what do they actually do? The principal is simple and could be, though not quite so elegantly, re-created with a desk fan. (Do not put a desk fan on top of your wood burner!) The heat produced by your wood burner will travel directly upward to the top of your room and that hot air will gently descend as it cools or is displaced by more hot air. The further from the burner you are the cooler it will be. The stove fan moves some of that hot air directly from the top of the stove further than it would naturally travel thus creating a more even dispersion of heat.

It works, there is no question about that. How well it will work will be determined by your installation. If you have a ventilation system in place then you may not notice a difference. We do not and as a consequence the result is dramatic. Draughty spots are lessened and there is not so much of a hot spot near the burner.

I have two of these fans, one I purchased and another sent to me for review by Valiant Stoves, a UK based company.

Upon initial inspection they look very similar; they are approximately the same dimensions and of a similar design. The Valiant is the 4 blade model (FIR360) whereas the unbranded model has two blades. Place both on the stove operating at an ideal temperature of 200 degrees Celsius and they begin to spin within a few seconds of each other. The unbranded one always starts first, possibly due to the lighter weight of the blade arrangement. Removal of the fans stops them both after a couple of minutes.

The Valiant is better finished than the ebay purchase, the motor is painted to match the colour of the unit and the handle functions properly, the unbranded one gets stuck easily.

I have tested both for a period of days under similar conditions, they operate similarly, the Valiant is totally silent, the ebay purchase is very nearly silent, I can hear a click every revolution if I put my ear right next to it. I hadn’t noticed until I did that so it’s not noisy by any means. After a few days of use when the stove pipe temperature had reached the upper limit of their recommended use, the unbranded one had a slightly distorted pillar, it had not coped well within the limit of it’s stated capacity and had warped! I was able to bend it back into place but that did nothing to restore my confidence in the cheaper unit. The Valiant had not suffered at all.

In summary, I am impressed with the performance, they both do what they are supposed to but the Valiant does it better, it is made to a higher standard and I expect it will stand the test of time.

If you want a flue thermometer to go with it you can get one here

SFN is a member of the Amazon Associate program, if you you our links to purchase products on Amazon we will receive a small referral commission, the price is the same to you so I would appreciate it if you could use our product links!


Painting inside a fireplace
(wessel bos) #2

Mass woodburners store more heat equivalent to their mass( Tulikivi)etc.

Funny that burners like this have no convection system integrated, and a stirling fan won't work on this and wont probably need one as well

Ordinary woodburners sometimes do have covection ,but are less effective on that ,equivalent to their mass and a glass door means generally a reduction off a quart of the mass since a burner has 4 sides.

20 years ago a was in the woodburner business for some time and bought an occasion GERMANE burner originally for coal ,with a tiny door ,from witch you only can see a glow,ie.for safety reasons. It carges from the top on a 45 degree angle,perfect to load long pieces of wood,unfortunately they cant be too wide,so i do a lot of splitting,but after so many years one gets really good at it!

This one one weighs about 300 kg.,chamotte stone 2 inches(the more thick ,the more heat storage) 50 cm sides and 130cm high.

the house is 180 m2 and reaches celcius 20 easily.

So buy them as heavy as possible,with chamotte as thick as possible,with convection ie double mantle.

wessel


(Ken Wildon) #3

Bought the Galleon offering from Amazon UK for £34 just before Christmas. Wonderful gadget. Pushes the heat further into, and around our rather large open kitchen. Whether or not it saves fuel I have no idea, but it certainly warms far more of the room.

Happy to recommend this product.


(Glyn Morris) #4

I’ve been a believer in the usefulness of stove fans for some time, my cheap 2-blader making a noticeable difference. However, if you’re not strapped for cash, the Vulcan Stirling-engined 5-blader is not only effective, it’s also a lovely piece of engineering. Guess what I got for Christmas?!


(Christine Phillips) #5

We also have bought a Valiant model recently as a result of this review but as yet we are not really impressed. We have an old Godin wood burner within a fireplace & usually have the front doors open as we like to see the fire (the doors are solid not glass). We have tried the fan with the doors closed & open but frankly we can feel no temp change in our living room at all even though the fan is whizzing round. We will persevere but if this continues I might well have a fan for sale soon.


(Paul Smith 3) #6

I purchased a fan as a consequence of reading the review and am impressed with the difference it makes. A simple tool but very effective.


(Carole Brown) #7

Can this be used if your wood burner is situated within a large fireplace?


(Kent Shelley) #8

Cheers, James.

Sorted.


(James Higginson) #9

Hi Kent, sorry I missed that. Indeed we do. Here it is, click on the image. Thanks!


(Kent Shelley) #10

Hi James and Catharine, perhaps you missed my earlier question: do you do a link to Amazon.fr as well as Amazon.UK as the Valiant is only 103€, ie: currently £73 there, as against £82.45 ? I fancy getting one and the postage will probably be less from Amazon France.

Valiant Amazon-fr

As an anecdote on that aforementioned subject of the difference in postage, I recently checked out and bought a cement mixer from Amazon. It was (equivalent) £229 with free delivery from Amazon .fr - and £209 with a delivery charge of £825.01 from Amazon .UK. I tried it 3 times in case it was a glitch. Hmmm !! I wondered if you got to keep the delivery van.


(John Withall) #11

Good luck with the new Godin, from you description it sounds as if that will certainly change things and then you may find your stove top fan will help as well. poor little f--t can only do what it can if there is sufficient heat to do it.

I know Jame's description above says 200c but that is only just at the point where coating the flue with tar lessens, far better to get it around 300c. I knew they had a bi metalic strip on the fans to lift the TEG if it got too hot but even then 400c isn't too hot for good combustion of the creosotes in the fire. Bad wood burners will have a similar temperature for the flue pipe as the walls of the stove itself, good ones will have the stove considerably hotter than the flue thus not taking all that heat and dumping it up the chimney to heat the outside space.

Fingers crossed for you and the pets this winter.


(David Rosemont) #12

It is always going to be difficult to adequately heat a large space as clearly the hot air rises and allows the cold air to drop to the level you are at. Frequently serious draughts arise as well and these tend to have a wind chill factor. In mediaeval houses they introduced inglenook type spaces adjacent to the fireplace to keep a cosy area. Don't forget also that people used to wear far more clothes indoors than many like to now. If your house is large enough maybe have a small winter snug room where you can pass the winters and then enjoy the wide open spaces of the barn room in the warmer months. Buy Damart or similar. Invest in throws. Drink alcohol.


(John Brian) #13

With a stovetop fan my woodburner gets heat into the corner of my large, stone living room. Without it it does not. This is a fact and can be proved by using a scientific instrument, a thermometer.


(Catherine Julia Stock) #14

Hey John. You’re Absolutely right. I actually have bought a Godin that pumps out 13k of heat when it really gets going, as opposed to my Supra which is only 9. I am waiting for my builder to install it and hoping that it will make a big difference. My present set up is fine until the temperatures drop below 0 for a couple of days and then we really begin to feel the cold. The stove actually sucks up a an almost whistling steady stream of cold air from the space downstairs. In Feb 2012 we had to leave the taps running continually for a month to prevent the pipes from freezing and all the cats and dogs and fully dressed humans shivered together in the bed at night!

So yes, the Valiant is the proverbial f–t in a hurricane. But thankfully the winters where I live in the Lot, though often long and wet, are usually quite mild.


(Carole Brown) #15

It does not look asthetically pleasing. .but if it helps !!!


(John Withall) #16

Catherine, I get the impression you are not warm enough, you have a ceiling fan already and were not warm enough with that so you have added a Valiant stove fan and are still not warm enough.

The bad news is whilst fans circulate the heat for a quicker more effective comfort feeling if the heater isn't large enough for the space you are trying to heat with it's poorly insulated walls as well you need a bigger heat source.


(Catherine Julia Stock) #17

hmmm. I stumbled onto this post and as I live in a large barn that is heated solely with a woodstove, thought I would invest in the Valiant fan. A caveat to others with large badly insulated spaces. I don’t think this or the large ceiling fan that I installed a few years ago makes any difference to redistrubuting heat in my space. I imagine it would work well only in a tightely sealed room.


(Kent Shelley) #18

Do you do a link to Amazon .fr because the Valiant is about £75 (€103) as against £82 there?

Valiant stove fan on Amazon .fr


(Cory Bixler) #19

My stove fits my fireplace tightly anyone have any suggestions where a heat driven fan will not fit?


(David Rosemont) #20

Some people rate these other devices for better heat distribution off radiators- I have no experience. Has anybody else tried them? Will have to start heating the house next weeke- help! No help from IDS this year!

http://www.amazon.co.uk/Radfan-Classic-Low-Power-Radiator/dp/B00GR0STTG/ref=sr_1_1?ie=UTF8&qid=1444900185&sr=8-1&keywords=fan+radiator