[Stoves] FA vs ND in TLUD stoves -- not what you might expect about cost

[Paul Anderson]

Stovers,

FA (forced air or fan assisted) and ND (natural draft) versions of TLUD 
stoves have existed since the original work by Tom Reed (both types) and 
Paal Wendelbo (only ND) in the 1980s - 1990s.   No need to describe them 
here.   Check the written documents.

What is not discussed much is the relative cost of these two major 
types.  Of course, the QUALITY of the stoves will impact the price, but 
let's assume that quality is similar, such as using stainless steel in 
key parts, and using modern manufacturing with possible high volume 
production .  Such stoves already exist or are nearly ready for the 
market, but are often overlooked.

In my opinion, many TLUD stoves are "over-weight", being made of metal 
far thicker than is necessary.   But assume similar weight optimization 
for both the ND and FA TLUDs.

Basically, a TLUD is a fuel chamber with additonal walls and legs in 
various configurations.  The differences because of ND or FA are 
primarily because of needed draft for combustion quality:

1.  ND needs natural draft, and therefore vertical rise is important for 
negative pressure.  An "internal chimney" (or riser before the gases get 
to the pot), or a chinmey after the pot is essential.

2.  In contrast, FA needs draft, but it is from a the push of a fan or 
blower.

The costs of "chimney components" vs the costs of "fan components" 
becomes the crucial issue.  And there are expensive and inexpensive 
variations of both.

But from what I am seeing, the chimney costs remain constant in each 
cultural context.  Many Latin American stoves utilize chimneys, as do 
stoves in mountainous and cold-climate areas.

But for the fan components, costs have been reducing  and reducing more 
while the general availability of getting the few Watts of electrical 
power is becoming easier and more widespread, essentially being costs 
covered by other desires such as lighting and charging mobile phones.

Basically, the costs to make a real chimney-based stove vs the componets 
in a functional FA TLUD stove are about equal now, and will be lower for 
the FA TLUDs as volume production kicks in.

Today, 2017, if a society (or individual household) has economically 
sustainable grid electricity, or a solar-powered lighting system, or 
established battery-recharging services, (and the education and 
experience to reasonably care of an electronic device), a FA TLUD will 
be a reasonable addition to the household.

Certainly, in ASPIRATIONAL TERMS, households will move toward the 
Fan-Assisted TLUD stoves, with cleaner combustion that can compete very 
well with LPG on cleanliness, while being environmentally and 
financially superior.

In terms of clean combustion of source-fuels that are dry biomass such 
as wood, TLUD stoves --- especially with fans --- are head and shoulders 
above any "ICS" (Insufficiently Improved Cooking Solution) stoves that 
use solid fuels.

Paul

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
Email:  psanders at ilstu.edu
Skype:   paultlud    Phone: +1-309-452-7072
Website:  www.drtlud.com