Why TLUDs?
- cooking 
- WASH
    - water pasteurization with optional Biochar water filtration 
    - sanitation 
    - hygiene 
- biochar, via pyrolysis of biomass fuel (cogeneration)
- other applications (see end of page)

Two main materials 
1. 304 chimney flue, 1.2m length, Oz made possible 
    1. 4"
    2. 5"
    3. 6"
2. 1.6mm 304 exhaust tube, 1m length, ? imported 
    1. 4"
    2. 5"
    3. 6"

- 4" is best for smaller stoves eg. Navigator 'Backup' V2, 'Light'' V2
- 5" is best for burners eg. 'Navigator Burner', Navigator 'Awesome' V2
- 6" is best for environmental fuel eg. Navigator 'Environmentalist' V3

Chimney flue is lighter weight/less steel and easier to grind than exhaust tube.
Exhaust tube will last for longer than chimney flue, but may not be an issue if the TLUD is only used occasionally.

Other materials 
- 20L oil drums
- 20L SS buckets
    - Biochar and smoke water collection 
    - Navigator 'Awesome' V2 heat and wind shield/pot stand/quench water collector

Essential tools
- 100mm grinder eg. A corded Makita plus 100 x 2.5 x 16 Makita discs
- kango 2nd cut file
- woodcraft vice

PPE
- welders helmet with 'Grind' option (unpowered)
- leather gloves
- cotton clothing 

Key findings from Navigator tube and slot system 
- based on core TLUD design principles of primary and secondary air, adapted for tube
- dual primary air slots rows are needed regardless of tube thickness, diameter or height. In the case of wood pellets, biochar recovery varies from 90-100%, as sometimes some wood pellets at the bottom and centre of the tube don't pyrolyse but can be avoided with a ss bottom mesh cone insert
- secondary air slots can be single row or dual row.
    - single row for small stoves & 6" environmental fuel burner (cooler and more fuel efficient)
    - dual row for bigger stoves and burners (hotter for water pasteurization but a single row for a 4" burner is cooler for slow cooking)
    - a ratio of 2:3 (height of secondary air slots to overall height of stove/burner) generally works well, though a little bit of tweaking for 4" and 5" stoves was tested with minimal gains in fuel efficiency 
- alternating slots for dual rows work best
- fuel eg. Wood pellets, vertically stacked sticks, up to 1cm below lower secondary air slots row at maximum capacity 
- Forced Air/Fan Assisted operation is not needed and not built into the system. The system is completely solid state with no moving parts or electronics. Electronic failures are avoided. Simpler supply chains too.

Pot stands used in different designs (plus tertiary air)
1. 220 x 40 2.5mm 304 cross piece (originally used as a primary air mesh support in the Flat Permastove), used for the 'Backup' V2, 'Versatile'
2. 130 x 30 1mm 304 cross piece (originally used in the Permastove V4), for the 'Light'' V2
3. Rectangular turret on top of smaller stoves, for the 'Milo tin' (see blog)
4. 1.6mm 5x5 304 woven mesh plus wok ring (optional modding), for the 'Awesome' V2 and 'Environmentalist' V3 
5. 1" x 500 304 square tube (x2, off 1m length), positioned parallel on eg. 20L oil drums or 20L SS bucket, 'Awesome' V2 and 'Environmentalist' V2
6. Woven mesh + modded wok ring wired to 2 x square tube lengths, for the 'Awesome' V2 and 'Environmentalist' V2
7. Universal Pot Stand (UPS), for the 4" and 5" 'Navigator Burner'
8. 1" 2mm 304 mesh, reinforced with slotted galv angle (wired) on the back edge, supported on besser blocks at either end, for the 4" and 5" 'Navigator Burner'

Cookware
- 2L/3L/5L ss billy
- 10L/15L SS stockpot (with possible ceramic fiber thermal insulation)
- cast iron skillet (very stable stovetop or oven (see below)/ss frypan
- wok

Other applications 
- Bakerstone oven heating (from below)
- hot water system
- urn
- high surface area Biochar for water filtration, Atmospheric Water Harvesting (AWH), battery anodes et al