Stirling engines are one type of fan but are noisy in operation as you said David. The other ones are thermoelectric generators (TEG, Peltiers) That are much quieter.
The number of fins is just to cool the TEG, one side must be hot, one side cool, the bigger the difference the greater the power output so the stronger the fan can be.
I am in the process of making my own for a bit of fun and have 4 TEG's under my desk waiting to be attached to computer heat sinks and then to the wood burner. Plenty of info on Youtube.
Got excited by this but then realised the horizontal beam across the top of our fireplace would block the fan ! Would need to drop the breeze block plinth that our woodburner sits on.
Heyup Bill! I'm a fan of woodburners but as much as I might want to get warm - I do not imagine sitting on one!! OK - only joking. Actually, we are hoping to move to La Belle France as soon as we sell up in Spain so I will be looking for some advice later. Cheerrs!
The burner is hot enough as the fans slows / speeds up depending on the temperature and at the moment it's spinning at full pelt. I think the number/size of the fins is the key.
You may not have your woodburner hot enough as well. Thermostat a good idea as it will tell you what the optimum level is. Ours has 5 fins each side so a more robust fan than yours and around 150 plus euros.
Yes, it's at the back, facing forwards across the burner top. My flue pipe comes out of the back of the burner, straight into the chimney so won't affect its performance. I think I need to find myself a thermometer and actually prove to myself the warmer air is being pushed towards the colder corners because it's whizzing around quite happily (and completely silently, lovely) so by the law of logic it must be doing something. I think sitting down at the computer all day doesn't help either because I automatically feel more chill. I need to be outside wielding an axe or something to warm me up.
Shouldn't be noisy so think you must have a cheapy, also you will not feel the air moving as the whole idea to is more the air gently. Ours certainly works and has certainly more than a couple of fins. We have had woodburners as our main source of heat for over 20 years. Unfortunately a lot of brits not used to them do not understand how they work. Size, capacity of both woodburners and fans and how you use them varies. Experienced as we are - we certainly found the ecofam airmax works well as we have large rooms to heat and have noticed the difference. Hey ho, horses for courses!
I shouldn't waste your money Bill. A friend gave us one which I think he had got fed up with. Apart from being a nicely made little Sterling Cycle heat engine , its sole virtue, it moves very little air and is infuriatingly noisy.
I'm wondering if it's purely where my fire is situated or where I've placed the fan (I'm experimenting on that front). I know about 15 ladies who are all raving about the 2 fin fan I bought so am wondering if it's just me having a senile moment.
Hi Valerie. Bought our ecofan 812 airmax last week (a larger version) and I can certainly say it does the job. It redistributes the heat more evenly and pushes it through into other rooms. We are extremely pleased with ours but I think you need to steer clear of small cheap fans. I think you only get what you pay for.
Forgot to say, mine has two fins either side and was about €70 (inc P&P). There are four fin available plus other circular designs etc, the most popular of which it seems is the Eco fan. For those you're probably talking €120 - €150. I don't know if their performance is better. Presumably the more fins, the greater the output?
There are several systems available that will alow heated air to be re distributed to colder parts of the house. they all rely upon 100/125mm dia insulated pipework between your wood burner and the cold room. three types are available.
1st and most efficient) An insert which has a jacket round it and a built in fan to eject hot air through two outlets which can then be diverted to your chosen area.
2nd) A heat exchanger which is wrapped round the chimney.
Also ran) A kit with fan which allows warm air to be removed from a hot area for instance over the top of a wood burner when it is enclosed in an old fireplace.
Hi BIll, mine arrived this week. I'd wanted one last year but never got round to it. I've heard rave reviews about how the heat is distributed and the general room temperature can increase a couple of degrees. To be honest, as yet I've noticed no difference although it is placed where it should be and is whizzing round like a mad thing.