lost heat

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

jjmelt

Member
Jun 24, 2008
31
southern NY
Hey guys
Just put in a wood stove. Unfortunitly I had to buy a cheap one. Can't afford anything right now. Its a free standing stove that I had to slide into my masonry fireplace. (not an insert) I'm having trouble sealing up the flue above the stove. I was thinking of drilling a 6" hole 3' above the stove into the flue then I should be able to seal up the 8x8 clay pipe with insulation and metal. But then instead of sealing the hole up I was thinking of installing a small fan to pull some of the heat out of the flue. Then I was thinking of doing the same thing on the second floor.
The flue runs up the center of my house. and I have a 6" liner running all the way up the flue

Thanks for any input.
 
No, no, no, no... no.

Do NOT put any kind of heat reclaimer on your flue, it will bring your stack temp down, creating issues with creosote build up.
 
my concern there would be pulling heat from your chimney is going to cool it which will allow creosote to form more easily. What kind of stove did you buy? Do you have any pictures.
 
thanks for the quick repy guys
Only 3' up from the stove top I didn't think would cool the stack that much. I have so much of the heat going up the flue that will be trapped when I seal it up.
Can I use the fire stop foam around the seal metal flue? I was going to do my best sealing the space with metal then spray foam the joints for a good seal?
I will try and send a picture asap
 
Pull that stove out of the fireplace if possible- it will improve efficiency by allowing air to move around the unit.

Air around your unit- quite liberating.

Anyway- if that's not possible, you might think of blowing cold air at the stove in a way as to improve heat transfer. Can give details if you're interested.
 
CowboyAndy said:
Do NOT put any kind of heat reclaimer on your flue, it will bring your stack temp down, creating issues with creosote build up.
What is the difference between that and having single wall inside a room with no flue?

The biggest problem I see with opening the flue on two levels is you are creating a route for fire to travel easily between floors if something were to go wrong.
 
jjmelt, No offense, but please read a lot of posts here before doing anything. Do a search on direct connect, blockoff plate, wood stove in chimney, etc. Maybe it's just me, but the way you described what you want to do seems a bit flammable to me. Remember than anything you put on top or in your chimney has to be seriously heat resistant. Please don't burn your house down or turn it into a big meat smoker. There are a lot of ways to rig what you want to do and it be safe.
 
If the flue is not sealed at the top, then a fan will be drawing a counterflow of cold air against the liner. That's a really efficient way to cool the pipe and cause an issue. If it is sealed, then a fan doesn't do anything really unless you have another hole for makeup air. Drawing air from the house and warming it is not nearly as bad.
 
Do you have, or intended to have a block off plate?? Is your pipe, double wall insulated?

And I agree with AP, I like lots of air surrounding my unit.
 
I tried to attached pic. I drilled two 4" holes in the back of the masonry box and installed a 4" duct fan to try and blow air from the stairwell that is behind the unit into the fireplace and around the stove. I also install two 8" duct fans in the ceiling (visible in pic) that blow air into the rest of the first floor. Which I shut off at night to let the heat go up the stairwell.
I would like to drill the 6" hole 3' above the stove and seal the chase up real good with steel and insulation. then leave the hole open to let the heat out. If I did a fan it would only pull air from below where the stove is.

Basicly I want to seal the flue up and make as many ways possible to get the heat out of the masonry space. I also was thinking of drilling a few 1" holes through the masonry to let the heat out. ( I have a 36" long masonry bit)
I can't pull the unit out any more. Flue wont line up. The flue is a single wall galv. pipe. I did put a peice of sheetmetal at the top of the chase trying to stop air flow a bit.
[i mg][/img]


Well picture didn't work.
I have no idea how to get the picture to work? any help?
 
You need a block off plate above your stove that fits between the masonry walls and flue pipe. I made one, if you look in the "main informational articles" their are instructions on making a block off plate. I was loosing a ton of hot air up the chimney before i installed the block off plate AND sealed it up - had it installed for 2wks with no sealant and i was very disappointed in my stove. Then i sealed the block off plate up with firebox cement and it was a whole new situation!! I can actually heat my house when it's cold out now. Good luck.

Not to sure about drilling holes in masonry or how much heat transfer you are going to get out of it.

Also did you say you used "galvanized" liner? Are you sure this is OK for a solid fuel appliance?
cruzer
 
Adios Pantalones said:
If it is sealed, then a fan doesn't do anything really unless you have another hole for makeup air.

What is could do is pull smoke out of any small leaks in the pipe and blow it into the house.

Edit: Based on more info, with the use of galvanized pipe, the above is almost a sure bet. ;)
 
jjmelt said:
I tried to attached pic. I drilled two 4" holes in the back of the masonry box and installed a 4" duct fan to try and blow air from the stairwell that is behind the unit into the fireplace and around the stove. I also install two 8" duct fans in the ceiling (visible in pic) that blow air into the rest of the first floor. Which I shut off at night to let the heat go up the stairwell.
I would like to drill the 6" hole 3' above the stove and seal the chase up real good with steel and insulation. then leave the hole open to let the heat out. If I did a fan it would only pull air from below where the stove is.

Basicly I want to seal the flue up and make as many ways possible to get the heat out of the masonry space. I also was thinking of drilling a few 1" holes through the masonry to let the heat out. ( I have a 36" long masonry bit)
I can't pull the unit out any more. Flue wont line up. The flue is a single wall galv. pipe. I did put a peice of sheetmetal at the top of the chase trying to stop air flow a bit.



Well picture didn't work.
I have no idea how to get the picture to work? any help?

jj, did you read this information about posting pictures? https://www.hearth.com/econtent/index.php/forums/viewannounce/27_2/

If that doesn't help, send me the picture via a PM or email and I'll post it for you.

It sounds like you need to put the block-off plate low, maybe at the lintel level. And it sounds like you need a blower on the stove. What make and model stove is this?
 
Thanks BE GREEN. What is your email? I did read the post about how to post a pic and I;m more confused now then before.

Unfortunitly my stove is the one from Home Depot. I'm not sure of the make.
I was going to make the block off plate. the only differance is I'm going to make it a bit higher then normal.
 
jjmelt,

Is there any room behind the insert for a 20 inch box fan with metal blades to blow hot air out into the room??

If there was room, you could get a lot of heat out. Otherwise, try aiming a 20 inch box fan at the body of the stove and see the heat that it blows out into the room.

Your 4 inch duct fan, is probably too small & probably does not move enough air to make a large difference.

You must block off the fireplace damper, properly, as too much heat is going up the chimney.


JJMELT Please click on the second url -making_a_block_off_plate/

as it contains the info you most need to know. The other two are just pics of how other people here, installed their fireplace inserts.

https://www.hearth.com/econtent/index.php/forums/viewthread/11697/

https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/

https://www.hearth.com/econtent/index.php/forums/viewthread/9630/P15/


here is the article that I got the above view threads from:
JJMELT go to wiki, directions below.

Wiki Note: it may be necessary to scroll down as some times the article appears 3/4 down the page instead of at the top of the page. REMEMBER THIS .please.


AT TOP OF THIS PAGE ON RIGHT CLICK ON HEARTH WIKI .
When wiki page opens, see on the left hand side of page wiki navagation .
from the wiki navigation list select & click on WIKI TITLE LIST
when the wiki title list page opens, you will see 3 collumns of titles.
Go to the right collumn, the third title up from the bottom, WHY DAMPER SEAL IS NEEDED
& click on this title. The article will open, probably 3/4 of the way down the page & off your screen, so scroll down to it.

HOPE THIS HELPS.
 
I know the 4" fans are small but they clam to move 250 cfm each. Thats 500 cfm which is about what all the inserts have. I plan to put a bigger one behind through the masonry. My wife needs a break from the hammer drill for a little will. So I hope to have at least 1000 cfm's blowing on the stove.
I understand how to buid and why you need a block off plate I just want to install it in a non traditional place. Up 2 or 3 feet in the flue.
I did use galvinized liner. is that a problem? I couldn't afford anything else. I'll change it next year.
 
Status
Not open for further replies.