On Sun, 06 Nov 2016 16:15:18 -0600, Mark Allread
wrote:

I recall a comment on stove fans that sit on top of wood/multifuel stoves
but cannot now trace it. Anyone else remember it or who commented please?

I've been looking at some on-line and they appear to fall into two
categories - stirling engine and 'electric' but I can't figure out how
the electric ones work without mains or batteries.

I'd have thought the simplest format would be a simple heat rise
updraught from the stove to turn the fan blades.

What obvious thing am I missing and does anyone have any recommendations
for *currently available* ones at reasonable price. The "Aldiddles" both
seem to have had some but no longer.

Over the years I have had a couple , the first was a Caframo imported
direct from Canada when suppliers in the UK were rare.
That was a peltier coupling type where heat differential makes enough
power for the motor to turn the fan. These are often used the other
way round in picnic cooler boxes where applying a current can make one
side cool the box
It worked well and I left on the boat where it was used when I moved
on from it.
A lot of the fans available on Ebay are Chinese rip offs of the
Caframo with varying degrees of quality.
The second one I purchased was actually for my mother who no longer
able to stoke a solid fired Rayburn got an oil fired boiler in for the
main heating but then found she needed a wood burner occasionally.
This was the Vulcan stove which is a Stirling engine type.
It is a far more interesting device to watch if you are the sort of
person who likes mechanical things like an old clock or steam engine.
It worked very well on my mothers large wood burner .
I got it back when she moved and tried it on my own stove , mine is a
lot smaller and the Vulcan doesn't suit it so well on it as the top
takes a long time to get hot enough so I got a valiant ventum III
which shifts a lot more cubic feet of air from a lower temperature.
Both the Vulcan and the ventum are UK manufactured.
I still like using the Vulcan when the stove is hot enough because I
like seeing it working.
This site is one of the best for comparing different models.
http://www.stovefans.co.uk/

The Ventum III is about £40 more on there than I paid a year ago
elsewhere, the Vulcan not a lot more than I paid for the MK1 version 5
years ago.
Whether you consider £60 to £150 pounds reasonable I don't know but
the cheaper ones I can't speak for. the operating environment is
pretty severe so you need good bearings so the fan doesn't vibrate and
drive you barmy and the thing grind to a stop after a couple of months
use.

G.Harman