navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Making Twin wall  (Read 3135 times)
Greenbeast
Hero Member
*****
Offline Offline

Posts: 2280


WWW
« on: January 21, 2013, 12:43:37 PM »

Don't want to pay 100 a metre for stainless twin wall thankyou-very-much!

I'm currently thinking galvanised spiral ducting lined with some ceramic fibre blanket (which i have) and an internal of some other kind of ducting

Do i need stainless steel or could i go with aluminium?

I'll probably fit s/s straight off the stove and then interface to my homebrew twin wall
Logged
Justme
Hero Member
*****
Offline Offline

Posts: 3526


« Reply #1 on: January 21, 2013, 12:54:56 PM »

Ali wont last long, in fact the wrong grade of stainless wont last long either.

Both get corroded by the flue gasses from burning wood / solid fuels.

 
Logged

Navitron solar thermal system
30 x 58mm panel 259L TS
1200watts solar 120vdc
FX80 Solar controller
Victron 12v 3000w 120a
6kva genny
6 x 2v cells 1550amp/h 5C
24 x 2v cells 700amp/h 5C
Total bank 4350 amp/h 5C
Greenbeast
Hero Member
*****
Offline Offline

Posts: 2280


WWW
« Reply #2 on: January 21, 2013, 01:00:41 PM »

That's exactly the info i wanted thanks, so i want 316 s/s for the inner skin?
Logged
Justme
Hero Member
*****
Offline Offline

Posts: 3526


« Reply #3 on: January 21, 2013, 01:52:13 PM »

Yes
Logged

Navitron solar thermal system
30 x 58mm panel 259L TS
1200watts solar 120vdc
FX80 Solar controller
Victron 12v 3000w 120a
6kva genny
6 x 2v cells 1550amp/h 5C
24 x 2v cells 700amp/h 5C
Total bank 4350 amp/h 5C
julian
Hero Member
*****
Offline Offline

Posts: 865



WWW
« Reply #4 on: January 21, 2013, 04:56:03 PM »

you know its not 100/mtr for twin wall liner, right?

ive just had a look on ebay, and 6m plus a selection of fittings, in 6" is coming out at about 190 (stainless, twin wall)


are you needing to go up an existing stack, or outside for a long distance?


one of our fires here is under an existing stack, so ill be using a liner, but the other has no stack, so ill be using a length of single wall from the stove to the roof (this is a single story building) and then some of the stainless twin wall i picked up used, off ebay, for the roof / external stretch.

as an indication, i got 4x 1m of twin wall in 7" ID (ie larger than most) and another couple of fittings for 100 all in.  ill need to buy a cowl and single to twin adapter (which will probably cost more than the rest of it!) but im never going to need the whole 4m so i may be able to ebay off what i dont use.


im right up for a bit of diy, but you may find that buying used may be just as cheap, and then you can spend your time doing something else? : )


Logged

Custom CNC engraved control panels for diy projects - http://thebeast.co.uk/?page_id=21
Greenbeast
Hero Member
*****
Offline Offline

Posts: 2280


WWW
« Reply #5 on: January 21, 2013, 05:30:50 PM »

oh!

The flue will be inside for ~1m  and then be outside for a good 2-3m
Logged
julian
Hero Member
*****
Offline Offline

Posts: 865



WWW
« Reply #6 on: January 21, 2013, 06:26:58 PM »

i dont know how much you want to spend, but, as i say, check out used on ebay - i think mine was cheap as a) its 7" ID [which actually costs more, but isnt as popular - which may have made it cheap] and b) its not selkirk
Logged

Custom CNC engraved control panels for diy projects - http://thebeast.co.uk/?page_id=21
Greenbeast
Hero Member
*****
Offline Offline

Posts: 2280


WWW
« Reply #7 on: January 21, 2013, 07:38:30 PM »

cool thanks
Logged
Ivan
Hero Member
*****
Offline Offline

Posts: 2262


« Reply #8 on: February 06, 2013, 04:20:40 PM »

316 is adequate for wood fuel. If you're burning coal you'll need a higher grade (920?) due to the more corrosive exhaust.

You don't need to insulate between the two concentric pipes. The air gap is good enough insulation.
Logged

www.epogee.co.uk - Solar PV & Solar Thermal Training / MCS
Justme
Hero Member
*****
Offline Offline

Posts: 3526


« Reply #9 on: February 06, 2013, 08:44:34 PM »


You don't need to insulate between the two concentric pipes. The air gap is good enough insulation.

Just remember then that the often recommended gap from the twin wall flue to combustibles will be substantially more than the typical 65mm.
Logged

Navitron solar thermal system
30 x 58mm panel 259L TS
1200watts solar 120vdc
FX80 Solar controller
Victron 12v 3000w 120a
6kva genny
6 x 2v cells 1550amp/h 5C
24 x 2v cells 700amp/h 5C
Total bank 4350 amp/h 5C
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!