Battery Size Required to Run a Blower?

[westbranch]

if you want to stay away from the battery during outages look at the Eco Fan, it uses a bimetal strip and ?? to run itself, there are 2 sizes. Made in CANADA
but also lots of US sellers...

They work great. If a in a large room go for the larger one, the small one works well in 2 -300 sq. ft. room

see here : http://www.caframo.com/ecofans.htm

HTH
Eric

[BB.]

There are also Stirling Fans for wood stoves... I have no idea if this is better or worst than the Thermal Pile fans of the previous post--or if the vendor in my link is any good or not.

Wood stoves tend to get very hot--and it is certainly possible that any of these fans can be "cooked" by overheated stoves (or blocked air flow).

-Bill

[westbranch]

You are right about the heat part Bill, the manufacturer has placed a bimetal strip on the bottom to 'lift' the unit slightly to keep its temp down. We use ours right over the firebox of our large wood cookstove. In the winter it can get the oven over 600 F so don't know just how hot the top gets? 4 winter seasons so far and still going strong...

Eric

[Mass Solar]

Thanks for the info West Branch. I was actually at looking at one of the fans, but I have a small insert vs a free standing stove. Any Idea how it would work on a small insert?

[BB.]

Generally, squirrel cage blowers (look like pet rat exercise wheels) work better against "back pressure" --- like that you would need when trying to "pump" air around a stove insert.

An open "fan" would not work very well at moving air against back pressure of ducting/stove if you tried to hook it up.

Also, your fan probably takes 40 to several hundred watts--I would guess that those stove top fans would only generate a few watts at best--so there is not near the same amount of energy available to move the air either.

-Bill

[westbranch]

I doubt that it would work on an insert unless there was at least 6 - 8 inches protruding into the room and then not that well.
They don't create a truly measurable air movement, just slow and gentle , that you do notice if you remove the fan, they seem to 'mix' the air more than a regular fan.

Eric

[icarus]

Both of the thermal electric fans work quite well. I have had a smaller one that has been in continuos service for at least five years. It doesn't stop turning from early October until sometime in April. I have a neighbor who has the larger one, and it too has been going 24/7 for 5 years or so. The really do move a lot of air (relatively) without any noise or fuss. You do have to be careful not to overheat them however.

I have seen the Sterling engine variety, but don't have any real knowlege of them, but it seems like it too would move a lot of air.

Tony

PS to add to Eric's note. The thermal electrics work best (sort of only) when they can draw cooler air. Thermal electric works with temperature differential, so they rely on cooler air. It is suggested that you put the fan on the back of a stove. Ergo: it won't work well on an insert very well.