Thomas Holm

Thanks Satamax. But I cant cut the chimney, too much work for an already bad implementation of this. I should have done my homework from the start. I read everything on the internet (or so it felt) before I started but apparently did not absorb the right information and did a poor job at implementing the information that actually got absorbed. My mistake. Maybe someone can learn something from this.

Satamax, you have been a true hero in helping me. Thank you so much! Your kindness, knowledge and creativity is a true inspiration.

Satamax Antone wrote:

Thomas Holm wrote:Oh. So that's the end then. Bummer... 😩

Not necessarily.

For example, i run a 220mm round riser, in a 200mm squarish, well square with rounded corners.  

Do what i was saying, cut the front of the chimney, and face it with bricks. Up to the ceiling. Or another easy way. Pipe up to the ceiling, and then plunge in the chimney. But  plunge with a 250mm pipe, so your transition is not too bad.  25xpi is 78, 53 cm circumference. By 13cm ; you end up with 1021cm² of ring projection  Since the gases go up. there"s 1/2  of it which works. So that's 510.5cm² for the transition. Not too bad. Even if it's a third, that's 340cm².

So imho. Not all is lost. You could even make your 25 cm diameter into a metal plate which affixes to the front of the chimney with gasket. And cut a bigger hole behind. 250 mm x 500 mm, and put the tube at the bottom. So for the first twenty cm above the pipe, your chimney section would be  if the bricks are laid flat, 24 x 25 cm.

You can then if needed, grind the top brick with an angle grinder and diamond disc. So it makes a funnel, instead of a shelf.

Oh. So that's the end then. Bummer... 😩

Chimney is 250x130mm plus or minus a few mm. Area 325sqcm. The 200mm pipe is 314sqcm so quite close. It is probably not the best chimney ever made and is not exactly straight. The stack effect is probably not best now in late summer with wet weather outside and cold/damp chimney but at least it is confirmed not too small as I understand it. Removed the plunger and will make that a bit higher now and a smoother transition to the chimney.

Yes! Very good idea!

Satamax Antone wrote:You pictured the same as this?

I have thought of a bypass. I could do a simple sviweling valve in the mass just after the big cleanout. Shut off a little more than half the mass. Don't know if that helps enough?

Cleanout is good. The little round door is a cleanout for chimney but its a long way, hehe. This is because I want to have a brick/concrete built kitchen top with stove on top and all pipes will be hidden under it.

Satamax Antone wrote:Also, if you do that little wall. Make a little door above or bellow your tube, to have a cleanout there. You won't be sorry.

And, there is a trick you could use, temporarily, to heat up your chimney. Make a bypasss from your big horizontal cleanout, to your horizontal tube cleanout.

No pic in transition area besides the one with rebar on top earlier posted. It's not the best transition though. Its among the first brick work I did and found it harder than I thought it would be. Probably not the worst either. Improvement is possible! Though i find it hard to picture how i would do it practically. I was googling pictures when doing it but didn't find anything that i thought was inspiring and useful. Maybe a case of bad google-fu.

I understand the wall and transition idea. Not to hard to do, thanks for that! Since I have to raise the funnel thingy it is easily done at the same time.

Satamax Antone wrote:Well, since you need to raise that pipe with the funnel.

What i would do, is make a  cutout of the width of the of the inside of the chimney; in the face they are jointing with the tube. About 60,70 cm high. Or whatever is needed. And rebuild a little wall against your chimney, to have a better transition area there.

If you see what i mean. That would shorten your pipe entering the chimney of  the width of a brick.

And also, do you have a photo taken from the top of the riser looking down  into your first transition area? It doesn't seem too bad to me. But what do i know.

Can't find the numbers now but when i checked it it was basically equivalent to the 200mm pipe. Otherwise I would not have done it like this. Will check that again. The transition to chimney is a sharp 90 degree turn, please feel free to suggest better solution.

The half barrel is covered in clay and still a bit wet.

Satamax Antone wrote:Well.

About the chimney?

What is your width and depth at the red line?





Then, have you filled above the half barrel bell?  If not, may be putting coton covers on it, to raise the temp could help. Your temps outside are not cold enough yet to drive a big stack effect. I guess you haven't warmed up the chimney before.

If the transition from 20cm tube, to the chimney is bad, i think i can offer a solution.

It's 30 degrees if I remember correctly. 400mm diameter. The 8cm gap was the maximum I could get with the current solution. You said at least 10cm at the time so I should have listened to you back then.
Did want to minimize the height of it all due to the surrounding environment, but will try to raise a bit. Its not that much work.

Thanks Satamax! You are a very helpful and I am very thankful.

Satamax Antone wrote:re checking your pics. The funnel at the end of the plunger tube is very  flat flared. It seems more than 5cm width for 5 cm height. (45°)  So this might well be a problem.

If you've chosen 8 cm gap. That means that with a X3 the CSA  That would mean 37.5 cm outer circumference of the funnel. Am i far?



Let's assume the height of the cone is 5cm.

8+5 13.

20cm X PI 62.83

62.83 x 13 =816.814 cm².

If the funnel edge is 37.5cm diameter, So 117.80 cm circumference. X the gap of 8cm.  942.47cm² Which is the X3 CSA  i have used to guesstimate.

Your 20cm  pipe's circumference, multiplied by the gap (estimated) of 13cm makes 816.814cm², so less than recommended ( by Peter) X3 CSA minimum

(well, remember that this is from the top of my rotten head)

Yes i know, i said earlier you could may be get by with 1.5 times CSA. I guess i'm wrong.

But you see my point above. Funnel too shallow. ney working. Imho.  Raise that bleeming edge to 10cm!


then i'll come to the other point. Or points.

The pieces are 5cm.

Satamax Antone wrote:Well. Daft question. Are those pieces of ceramic board well stuck to the firebox's edge? What depth are these?



If anything over 5cm deep.  That's no good.

Re checking your plunger tube. It seems awfully low. You say 8 cm?

Ahh, that's because the photo was taken before i put the ceramic board pieces back! Sorry, I should have explained that.