Adding 2 feet of Duravent Duratech SS - does it help?

I am thinking of changing my top 3 foot section to a 5 foot section (with a support brace). This will give me 2 more feet of chimney pipe. Currently I have 15 feet and looks like it is just short or very close to the 2-10 rule (dealer installed).

Once I do this I will lose the ability to change/clean the cap easily.

Has anyone ever added 2 feet with Duratech and seen any difference?

My draft at full burn is .12 but I get small amount of smoke sometimes at reload. I am reloading at 300 degrees on stove top.

 

I had Duratech installed last fall by chimney shop. I have to check the numbers, somewhere around 13 feet or so.

I have a few challenges here. Leaky old house. Stove in kitchen in rear of house can give me stack effect problems. Wind can spill over line of dense hemlocks and push air down to class A chimney. I had sluggish draft/cold plug as Class A went through small attic space. Only a few reverse draft days.

We added two feet class A and it is much better. I am considering an outside air kit though. Too many leaks, dryer, bath fan to overcome. It makes sense for me.

One thing I did find is that smaller splits can make a huge difference getting up to temp and making coal bed quicker.

As far as smoke coming back in at reload, open door very slowly, but the firebox and flue temp may have dropped that the draft slowed a bit. Do you open the primary air a few minutes before reload? That can help sometimes.

Just another note. Using a chimney cleaning system like the Sooteater can get the entire stove pipe clean from the stove to the cap. Shouldn't be a problem.

 

So I go add 2 feet to the chimney to get the smoke away from the eaves during burn cycle and help with reload smoke sometimes. Well it made it worse. About 2-3 minutes after starting a fire Now I get smoke out the rear of the stove to the side of the secondary inlet. I thought the stove leaked at first but it appears the rear of the f118 cb has secondary inlets on rear of stove hidden to the sides of the flash fire lever. No smoke out the front of the stove. Once I close the door it goes away. I'm chasing my tail.... I'm going to remove it and see if it goes away.

 

I added 3 ft Because on very windy days Id get a back draft at times.. It made a big difference. I have a hard time getting at my cap now so I took the screen out of it so it doesnt get caked up again.

 

When I added the 2 feet the draft went up .01 to .02 but when the wind blows the draft gauge wiggles and jumped more...but really need more testing time. Im removing the vacu-stack and going to a rooster tail soon. It didn't perform well during high winds, with constant changing direction. If all else fails Ill get the home pressure tested.

 

What is the relation of the stack to the rest of the house? Does wind spill over the house or trees and push air down to the stack?

 

its on the backside of the house. no trees in front or rear of house but 60 feet away some oak trees.

i watch the chimney on a camera wind is all over the place and constantly changing. the smoke doesn't go up a lot it tails.



but the shorter chimney handle the wind better..better as steady draft...
ill keep testing it to see if it runs ok in high winds.

the cold air will drop in the chimney. so far this week the draft guage shows a draft even before lighting.







but once the new cap comes ill update. im going to try double wall stove pipe. my chimney doesnt get much sun.

not many burn testing days left.

 

I hope this helps others with smoke on start up or even puff backs near startup. It can still be cold chimney or a stove not up to temp yet.

So in the morning I measured my floor temp near the bottom rear of the stove basement today It was 60 degrees. My stove is always colder at the back. I believe this is the problem. My 3 foot run of stove pipe was really cold too. So to test the cold chimney scenario which I thought I fixed because it worked with the 15 feet of chimney pipe.

I decided to heat more and much longer...heat the room up with a heater and heat the stove inside up with harbor freight heat gun. Then added pine kindling to a fire starter with some newspaper and closed door...then kept opening door for 5 seconds or so and added wood until the stove got hot. No smoke out the back of the stove. If I leave the door open on start up too long I will get smoke out back. It must be the cold pipe pushing it down. The longer the chimney pipes or stove pipe the more you have to heat. The old plan of 5 minute of the heat gun with the new added chimney height didn't work.

I'm sure this is over kill and will learn what I can get away and if I can load fully and light. To help double wall stove pipe is on order.

Also adding chimney height made my damper not work as good, I cant adjust under .09 but I can live with that. It could be the winds this week.

Now the test is to leave the door open for viewing (or how long while re loading) after the 2nd reload to see if I get smoke out back. Not that I need it, this version of Jotul f118 cb is supposed to work with open door fire viewing, Keep you updated