Results 1 to 15 of 15

Thread: Wood stove heat reclaimer

  1. #1
    New member
    Join Date
    Nov 2009
    Location
    Willow, AK
    Posts
    8

    Question Wood stove heat reclaimer

    Hello to all, I'm a new member and have viewed several threads in the past and now have a question of my own. Just had an idea for reclaiming stack heat from our wood stove to direct it upstairs and wondered if it was safe and or feasible. We have a 6" single walled pipe transitioning to metalbestos just before the ceiling. Tons of heat off the single walled pipe none off the doubled upstairs duh. So I thought could you wrap the 6" single walled with 4' of 8" single walled pipe leaving a 1" airspace between pipes and 1" above the stove top for draw. Transition into a 8" T with the top of the T ending where the pipe goes to double walled. From the opening of the T go into a 90 upwards then penetrate the ceiling/floor and cut in a floor register allowing heat to be drawn up from the stove top and between the pipe sandwich. mmm... Possibly install a fan to help pull more air through. So with that I wonder is it safe to wrap one pipe in another, would heat build up to unsafe temps, what about carbon dioxide? Seemed pretty simple to me so I figured there would be some sort of catch and or disadvantage. Any way comments would be appreciated just trying to keep the heat.
    Thanks

    By the way any help from Gooch would be invaluable. That guy is totally livin the dream! Full On

  2. #2
    Member SusitnaAk's Avatar
    Join Date
    Feb 2007
    Location
    ANCHORAGE
    Posts
    782

    Default

    Whew,Thats a idea, for sure. However most of us are trying to keep from going upstrairs, and forever thinking of ways to push back down to the floor. Remember heat rise,s Can,t speak for all but mine is always 90 upstaires and 70 downstrairs,With the use of fan,s one 12volt and one 110 ceiling when gen, is on, i can get them 6-8degree of each other. Lets us know how that works.

  3. #3
    Member JOAT's Avatar
    Join Date
    Aug 2007
    Location
    Soldotna, ALASKA since '78
    Posts
    3,720

    Default

    There's nothing specifically unsafe about what you're describing (if I envision it correctly), but it seems like more work than you really need. Since your plan calls for cutting a vent through the floor to put in a register, just do that. There shouldn't be much need for adding the ductwork from the pipe, just let the heat naturally go up through the hole or push it with a small vent fan.

    So if your upstairs is sealed off from below to the point where you are seriously considering this plan, I'd start by just putting in that floor vent register and see how much heat transfer naturally occurs before doing anything else.

    If that turns out not to be enough heat, then maybe you could try your idea, but don't sleeve the entire single wall pipe, just put about 2' worth of jacket up near the ceiling and duct that to your register. I think you'll be grabbing more heat than you really want if you go any more than that.

    Carbon Dioxide isn't a problem. And as long as you don't punch a hole into the main stovepipe, Carbon Monoxide won't be a problem either.
    Winter is Coming...

    Go GeocacheAlaska!

  4. #4
    Member Vince's Avatar
    Join Date
    Jul 2008
    Location
    Fairbanks most the time, Ancorage some of the time,& on the road Kicking Anti's all the time
    Posts
    8,989

    Default

    i think a stack robber would be easier and more cost effective to do.. the maintenance on them is a PITA but like anything the soot will build up in it.. so 6 of one....


    there are fan powered ones and static ones available in various stores.. AIH, northern tool, Cabelas has a version too....
    "If you are on a continuous search to be offended, you will always find what you are looking for; even when it isn't there."

    meet on face book here

  5. #5
    Member
    Join Date
    Mar 2008
    Location
    wasilla
    Posts
    788

    Default

    I cleaned chimney's for 15 years and the stack robbers cause more trouble than what you get in return. The 6'' pipe will plug up faster with that as well.
    Moving Heat
    I use to run into this problem with other customer and there is a couple ways to go. The floor vent is the best and lowest cost but you have to have a return air vent on the other side of the room. Heat goes up and cool air drops so you have to make sure the cool air has a way to drop and a place to go.

    The way we used to find out if the air was moving was to tape some toilet paper in the door ways and stair way and that would help tell where the air was moving. It sounds a bit hoaky but you need to see how the air is moving and where to fix the problem.

    Ceiling fans are one of the best to get air moving but you have to reverse the fan so it will i believe pull the heated air up and then it is forced to the walls of the room which is the cold spots (windows).

    I hope this helps you or others with this information.
    Good luck

    Sweepint
    Wasilla, (when not overseas)
    '' Livn' The Dream ''
    26' Hewescraft Cuddy, twin 115 Yam

  6. #6
    New member
    Join Date
    Nov 2009
    Location
    Willow, AK
    Posts
    8

    Red face

    Thanks to all who responded to my inquiry. I know we have an uncommon issue with heat as it should rise to the upstairs. We have in fact cut in one floor vent with an inline fan directly behind our stack which has made some difference but the fan is pretty loud. I think our next step is going to be a second and possibly larger vent to hopefully get enough draw between the two levels. Our ceiling/floor is also insulated which I'm sure holds more heat downstairs along with our vaulted ceiling upstairs being under insulated combine to make it 15-20 degrees cooler upstairs. We are still experimenting with our ceiling fans upstairs and in the stairwell to get the heat flowing in the right direction. I thought that the idea of wrapping the pipe to obtain some super heated air with out the creosote and maintenance sounded good and wondered if anyone else had something similar in operation. Every BTU counts!
    Stay warm

  7. #7
    Member garnede's Avatar
    Join Date
    Sep 2007
    Location
    soon to be back in Alaska
    Posts
    1,214

    Default

    Just be sure that you do not rob too many BTU's. If you take too many the flue gasses will be cooler and can freeze around your chimney.
    It ain't about the # of pounds of meat we bring back, nor about how much we spent to go do it. Its about seeing what no one else sees.

    http://wouldieatitagainfoodblog.blogspot.com/

  8. #8
    Member
    Join Date
    Feb 2008
    Location
    Fairbanks, AK
    Posts
    378

    Default I would just cut a hole in the floor

    just like Joat suggested.

    I would do nothing to rob heat from the flue gas. You do not want creosote building up in your pipe and risk a chimmney fire. I am thinking a stack robber would create similar chimmney fire risk.

    Do whatever you can to increase air movement throughout the interior of the house, and don't mess with your chimmney.

  9. #9
    Member
    Join Date
    Oct 2007
    Location
    Eagle River, AK
    Posts
    124

    Default How big is your upstairs

    There's alot a good, accurate advice so far on this subject.
    The key piece of information that is missing is how large of an area is this "upstairs" area you want to add heat to?
    It seems you want to be able to make up an approx. +20 differential.

    You can do this in a passive way as others have suggested, by adding in grills or registers. There was some very good advise earlier that you must take to heart if this is going to work-- you must have both a "supply" grill where warm air passes thru, and a "return" grill where the cooler air can drop back down into the lower area, and be reheated. The most common mistake people make when doing these things in cabins, is that they underestimate how large the actual opening areas ( vents ) need to be to accomplish this. One 4x10 floor register isn't going to cut it. Neither is 2. 4 is a maybe.

    A better appoach, if you have power, is to use one of the better quality "inline" fans such as a Fantech brand F/FG series fan. These use energy efficient, and quieter operating, EBM-type ( Papst ) motors. You can also put a reostat-type speed controller on them to dial the fan speed to whatever you like ( but stay within 50-100% for the motor's sake ). They come in various round-collar sizes and cfm capacities. They still produce noise, however.

    If you bought one of those inexpensive " duct boosters" ( propeller blade fan with a tiny motor, mounted to a little piece of round duct ) -- these are very noisy, and connot be used with a speed-control. They work fine for what they are designed to be- but some people have expectations for these fans that, frankly, just aren't reasonable.

    Let us know how big of an area the upstairs is, and we can tell you if it's even practical to pick up that additional 20-degrees you want with a basic, inexpensive air circulation approach. If it's a large area, sometimes the only real solution is an auxilary heater for that particular area.

  10. #10

    Default

    That is a some great advice. I know in my situation I have a wood stove and I just increased my stove pipe size and I produced enough heat to heat both my upstairs and down.

  11. #11
    New member
    Join Date
    Nov 2009
    Location
    Willow, AK
    Posts
    8

    Default

    Insulation and poor design... The culprits. Since the last cold spell we have discovered the reason for our cold upstairs. Our 2nd level is cantilevered over the lower section of our house. The floor between is insulated in the bottom of the cavity but not on the sides i.e. exterior wall. The cold air simply penetrates the bays above the insulation and holds the hot air down and further chills the upstairs. So by popping down the soffits and pulling the insulation from the center of the bay and filling the void of the cantilevered space. Cold air should stay out and heat should be able to pass more freely between the levels...? We'll see next - temps. I still want to go through with my original idea with the heat reclaimer although with some more thought out changes and suggestions. I like the idea of it not being intrusive like a stack robber, just a pipe wrapped around another, and the air should be super heated enough. We'll see on that also, still trying to sell it to the girlfriend. More ideas?
    Thanks
    fuzzy

  12. #12
    Member
    Join Date
    Nov 2009
    Location
    California
    Posts
    335

    Default If this were my problem

    I tend to think that the hot air is at the same dencity across the bottom floor celing, which is causing the air not to exchange.
    By putting a pipe with a damper from the floor of the up stairs to the floor of the down stairs , one is providing a route for the cold air to pass. providing a damper mid streem you can regulate the heat up stairs. I don't think a fan is necessary.

  13. #13
    Member SusitnaAk's Avatar
    Join Date
    Feb 2007
    Location
    ANCHORAGE
    Posts
    782

    Default

    I wonder if the place was built in steps and floor once was the roof, that would explain the way the insl. was. One would of wanted that way if it was a roof. Sounds like your on the right track.sealing that up. Still like the others said, I would, cut some nice vents in the floor.I would think that would be easier, Than the stove pipe thing.I like to keep my pipe simple. Hears a thought, if get little fire going in that pipe, you wouldn,t be able to see it turning red before it really gets going, until you hear that thing roaring out the top. if you seen it going red just a shovel full of snow in the box could stop it. The vents and use of fan will work.Keep adding them til get the temp where you want it.Just my two cent,s Let us know how it comes along.

  14. #14

    Default

    Not sure if I'm picturing this correctly, but are you saying you have single wall downstairs and then insulated from the pass thru, thru the second floor room and then out the roof?

    If so, a friend had the opposite. 6 inch standard pipe thru both floors and insulated out the roof. He cut a 6 foot section of 8 inch double insulated pipe length wise and put a piano hinge on the back of it. He wraps it around the pipe when he doesn't heat on the second floor and takes it off when he does. Not the cheapest solution tho.

  15. #15
    Member
    Join Date
    May 2009
    Location
    POW
    Posts
    71

    Default

    You might look at rocket stoves.

    Here is a place to start: http://www.rocketstove.org/index.php...tpage&Itemid=1

    I've heated with a bunch of stoves, including masonry heaters. My next stove will be one of these. I like stuff I can make myself.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •