Woodstove pipe heat reclaimer?

[ebinmaine 67,594]

Anyone use one of these?

 

I've read/heard both good and bad about them. 

The good is that you're getting more heat from the stove by taking some from the rising smoke. 

 

The bad I've read is that some folks say the pipe cools too much causing draft issues and possible creosote increases.  

 

Any thoughts?

 

 

 

[Pullstart 62,905]

You need a good draft for the chimney to vent properly and keep you safe.  Maybe thermometer to test vent stack temp would be helpful.  I think it’s something that shouldn’t be in the system.  The stove scrubs enough heat to keep everything working properly by design, but a temp reading would help determine if that’s actually true.

[ebinmaine 67,594]

16 minutes ago, Pullstart said:

You need a good draft for the chimney to vent properly and keep you safe.  Maybe thermometer to test vent stack temp would be helpful.  I think it’s something that shouldn’t be in the system.  The stove scrubs enough heat to keep everything working properly by design, but a temp reading would help determine if that’s actually true.

Agreed. 

 

Trina has a stack thermometer on both woodstoves already. And she uses them. Every. Fire. 

 

I've considered getting a pipe heat blower but never done it for exactly the reason you state. 

 

[AMC RULES 37,130]

Why do think you need one?

[ebinmaine 67,594]

3 minutes ago, AMC RULES said:

Why do think you need one?

Merely too capture more heat instead of letting it out the chimney. 

My thought is that if it was amazing ALL woodstoves would use it .... ?

 

 

[Pullstart 62,905]

6 minutes ago, ebinmaine said:

Merely too capture more heat instead of letting it out the chimney. 

My thought is that if it was amazing ALL woodstoves would use it .... ?

 

 

Yup.  If appliances could be 100% efficient, they would be.  For example, gas water heaters begin to condense in the flue at about 82% efficiency.  At that point, the condensation contains enough moisture from dew point of heat loss that it becomes corrosive.  I don’t believe there’s near as much corrosive properties in wood flue gas, but then you have carbon build up in the chimney, etc.  that airflow and temp to carry it out is crucial.

[ri702bill 8,328]

I know you are talking wood stoves, but.....

My father in law had a Better 'n' Bens COAL burning stove in the parlor at the other house - even on low, it would roast you out of that room. We added one on the stovepipe to push warm air into the dining room - added a thermostat so it would only function with air that was warm or hotter, no movement with cold air. Coal stoves burn cleaner than wood - no issues....

Bill

[lynnmor 7,307]

I cleaned my chimney and stove pipes yesterday, I never had so much buildup and tar.  I cut down two dead locust trees this fall and they produced the nicest firewood, since they were standing dead I thought it was good to burn, so I brought it straight in.  Apparently the moisture content was real high causing the problem, I need to purchase a moisture meter, (suggestions?).  The chimney cap is like a stainless steel box and it was so gummed up that I gave up getting it completely clean, I would imagine that the heat reclaiming thing would have been even worse.

[Pullstart 62,905]

When we heated with wood indoors, I cleaned my chimney and stove pipes MONTHLY.  Overkill?  Yeah.  Safe?  Absolutely.

[Handy Don 12,235]

36 minutes ago, Pullstart said:

Yup.  If appliances could be 100% efficient, they would be.  For example, gas water heaters begin to condense in the flue at about 82% efficiency.  At that point, the condensation contains enough moisture from dew point of heat loss that it becomes corrosive.  I don’t believe there’s near as much corrosive properties in wood flue gas, but then you have carbon build up in the chimney, etc.  that airflow and temp to carry it out is crucial.

I concur. Our 96+% efficient gas hot water maker has a blower to move air through it, stainless steel combustion and exhaust areas, and a condensate drain. Exhaust air is surprisingly cool after all that.

[Achto 27,601]

The Voglelzang design one that you have pictured is not the best reclaimer. Very few heat flues and no way to clean them. Magic Heat is a much better design for reclaiming heat and it has an internal scraper so you can clean the flues every day. 

 

https://www.shelllumber.com/magic-heat-mh-6r-heat-reclaimer-8000-to-30000-btu-black-for-6-in-bottom-crimp-chimney-systems.html?feed=Froogle&gclid=EAIaIQobChMIm6Ov54fc9AIVTsmUCR3-CgwrEAQYCyABEgKaS_D_BwE

 

We had one of these above the Wonder Wood stove in the house when I was young. It was like adding a second wood stove as far as heat output. As mentioned above it can cause your chimney to run too cool resulting in build up inside the chimney. To keep this in check, Dad would clean the chimney 2 or 3 times per heating season. Never had a draft issue though. 

 

Wood stove and Magic Heat got moved to the garage after Dad installed an add on wood furnace in the basement.

Edited December 11, 2021 by Achto

[JCM 9,177]

I second what @Achto said. I used a Magic Heat unit in one of my camps up North for many years. It was used primarily because when I was heavy into snowmobiling and arriving late on Friday nights it would usually be around Zero inside. This helped bring the temp up in the camp but was only used for roughly 2 or 3 months. I eventually removed it and gave it to a neighbor here in Southern Maine. I would agree with full time winter woodstove use you would need to keep an eye on the flue passages. Think I bought it from Northern Tool for just over $ 100 dollars around 1995. Nice quality unit though.

[wh500special 2,184]

1 hour ago, Handy Don said:

…Our 96+% efficient gas hot water maker…

I really enjoy your phrasing there!

 

There’s no “hot water heater” in my house either…

 

Steve

[ebinmaine 67,594]

22 minutes ago, wh500special said:

I really enjoy your phrasing there!

 

There’s no “hot water heater” in my house either…

 

Steve

Steve you ever get the chance to stand around and shoot the breeze with @Handy Don you'd be pretty impressed. He's a bright one. 👍

 

 

 

[roadapples 6,983]

When I started burning wood many moons ago my dad told me to open the damper and the stove vent and let it roar for about 3 minutes every day. I did this religiously every morning when I loaded the stove. I checked the chimney occasionally, but never cleaned it in the eleven years that I lived there and it was as clean as the day I started using it. But "you have to start with a clean chimney"

[Pullstart 62,905]

1 hour ago, wh500special said:

I really enjoy your phrasing there!

 

There’s no “hot water heater” in my house either…

 

Steve

“Hot water heater” makes everyone in this household cringe…

[SylvanLakeWH 25,598]

 

We have quite a few water heaters…

 

40 gallon natural gas

 

Stove - natural gas

 

coffee maker - electric 
 

Microwave - electric 

 

Fire pit - wood 

 

Two mirrors and a black pot…

 

Couple fish tank heaters…

 

Two ‘s with ICE’s… in a pinch they will heat water or fry an egg if you’re patient…

 

 

[wh500special 2,184]

2 hours ago, ebinmaine said:

Steve you ever get the chance to stand around and shoot the breeze with @Handy Don you'd be pretty impressed. He's a bright one. 👍

 

 

 

It shows.

[Yossarian 208]

@ebinmaine the forums on Hearth.com are the Red Square of wood heat.  Just like here, I've learned far more than I could ever contribute from very knowledgeable and friendly people.

 

That said, I think a lot would depend on the stove, the wood and the flue.  If you have an efficient stove,truly seasoned wood and well designed flue, then I think you could safely use a heat exchanger.  But you wouldn't need to, because you're running an efficient stove with seasoned wood and well designed flue.

 

After reading a bunch of threads on Hearth.com I used some incense sticks and traced the airflow around my house.  Then I set up a small fan on the floor in the doorway of the coldest room.  It creates a convective loop that moves cold air toward the stove and hot air down the hall into the coldest part of the house.

[Ed Kennell 38,210]

5 hours ago, Pullstart said:

, I cleaned my chimney and stove pipes MONTHLY.

Same here.    My Alaska air tight stove is in the basement.  I have a  duct work with a fan that pumps heat from the stove and pipe to  the kitchen and living room areas above.   

[Oldskool 6,644]

I agree with @Achto on the Magic Heat reclaimed. We used one for years in the old garage. It worked great. It was really nice with the thermostatic controlled fan option.

I also agree with @roadapples with the periodic "let it roar" concept.

 

Ours used to be 8ft of stove pipe straight up from the stove, attached to a suspended brick chimney.

We would let it roar in the morning. While tending the stove we would tap on the pipe with an old lead smelting ladle and let the creosote fall in and burn off.

 

We never used "good" wood in the garage. It was always standing dead. Spruce,fir,pine,hackmatack,poplar heck even alder.

Never had to clean the chimney in 10yrs.

Checked it twice a season.

[KrazeyOlDave 860]

what about just using a series of heatsinks with a nice little fan behind it to circulate the unclaimed heat?