Chimney Heat Exchanger

Wow! I found something interesting...

http://www.chimneysweeponline.com/horobber.htm

I lived a number of years in a very rural area, with wood stove the only source of heat. I put one of these little jewels (as pictured above) in, and had very satisfactory results.

The link here tells us, in some cases, that a 'Stack Robber' is not even allowed by some model codes! There is some valid discussion there, I suppose, on that subject.

I don't know... looks like you can still buy them. I worked in a small-town hardware store as a kid, and I sold these, as pictured and with the blower in the back. I cannot remember that we sold one intended to be ducted... we might have simply not stocked them. I do remember, I sold a bunch of 'em.

Yeah i know all about the plusses and minuses about using these.

The magic heat worked but as very cheaply built and hard to keep clean, which is the main problem with them.

This "Commercial" version i had for at least ten years and worked great. a simple cleaning lever once a day and never ever had to clean it otherwise as well as the chimney too it was awesome.

But all i can find is these cheapy ones.

Tghis other one had like three times the heat exchange tubes that were like three times longer also, and a actual blower not a fan. it moved a LOT of air.

More heat came out of the unit that came from the stove itself!

Joe

Well, NSS, is it practical to have one made at a tin shop?

Not really much to them... of course, anything homebuilt will not be UL listed, so your insurance guy might have a massive MI if he sees it installed!

Very True he he he

Check carefully what you are looking for. Some may be catalytic converters, will actually burn unburnt gasses leaving the stove.

Good stoves would have a secondary burn, with secondary air control and firebox. Familiarize yourself with creosote buildup and chimney cleaning, and chimney fires. I had a chimney fire once, a real scary situation.

I've heated my home with wood for most of my life. Close to 40+ years, so know all about all the hidden dangers.

I just miss that old exchanger. I left it at the old house where i used to live. Now i wish I had taken it with me.

Joe

I stuck a metal pipe down through a chimney years ago. And pumped air into the pipe and out into the room. So I guess it robbed heat out of the chimney. It was a one inch diameter or so steel pipe.

It warmed up the room almost as much as the woodstove itself. (Maybe this is an exageration).

It is probably totally illegal to do this. Another bonus with it was that it stayed working for maybe an hour after the stove went out, sucking warmth out of the chimney. If you have a good draw on your woodstove, you could do it. Drawbacks are probably that you will get more creosote in your chimney. (Just my guess). Creosote would condense on the pipe? You gotta blow the air in so there is positive pressure. I think it is worth experimenting with. It is a lot of extra heat.

I used a low pressure pulser pump to pump the air. (That was a mistake because the air coming from a stream or river through a pulser pump has a fishy smell). A weak fan would probably do a good job.

Brian

There are small centrifugal fans (some burner fans for instance) that have adequate static pressure for this. They could be retrofitted to the unit pictured, with distribution duct to the space.

Cooling the stack gases too much will condense acids onto the exchanger and/or stack piping, resulting in corrosion. If the exchanger is kept relatively small, like this, such problems are less likely. Nonetheless, periodic inspection of the stack would be a good idea.

Try googling this:

"magic heat" wood stove

I hope this helps.

John