[Stoves] Balancing Technical and User Objectives

Tue Jan 2 18:37:34 CST 2018

>
> it is useful in selecting the most
> promising products for field trials, and thus we have employed it in this
> study [109]. »
> Sigh.
> Haven’t we said so many times that the WBT should not be used to select
> stoves?

select? who select for whom? after certain stove is "selected", what will
be done to that stove? Here we can't see the users, customers, cooks'
evaluation, which is the real and right person we should serve. no place
for them, isn't that strange?

so strange paradox appears, that's not strange. it is a circus, because
free money attract clowns.

2018-01-03 6:49 GMT+08:00 Crispin Pemberton-Pigott <
crispinpigott at outlook.com>:

> Dear Xavier
>
>
>
> Well, this is the main misrepresentation:
>
>
>
> “…and provides for repeatable and low cost testing…”
>
>
>
> A major problem is the non-repeatable nature of the results. Ask Prof
> Lloyd. That was his main objection before discovering the legitimacy issue
> with the low power metrics.
>
>
>
> If all the math errors were removed, and the unwarranted uncertainties
> caused by the boiling point issue, we would have a water heating test that
> considered the thermal mass of the pot, the heat transferred, and a
> comparison of emissions and efficiency per MJ delivered. The contextual
> issues would, of course, remain.
>
>
>
> This is exactly what you get using the IS 13153 from India. They have none
> of the math errors, they consider correctly the heat gained by the pot and
> water, they do not have a boiling point confounding issue, and it retains
> the contextuality problem.
>
>
>
> So, given that the IS 13152 has been around for 26 years, it is reasonable
> to suppose that by now stove designers could have used it to compare the
> results of tweaks.
>
>
>
> In praise of that test method, I used multiple ideas contained in it while
> developing the HTP including the pot-swapping, the avoidance of boiling,
> the method of capturing the thermal mass of the pot in the calculation of
> the energy delivered, and avoided the problems caused by the fueling on
> command rather than on demand, and of course the use of multiple power
> levels.
>
>
>
> The CSI method treats the technical matters in the same manner but
> recognizes that three arbitrary power levels is a substitute for a context
> of use. In fact there may be such a three-stage context, I just haven’t
> seen it. So, the ‘big advance’ in the CSI method was to take the guts of
> the HTP and remove all the arbitrary power stages and replace them with
> something based on observations.
>
>
>
> The only remarkable things about the WBT is the refusal by its custodians
> to correct the mathematical errors that lead to the strangely uncertain
> outputs.
>
>
>
> For anyone who wants to know who s small change in their stove affects its
> performance, use the Indian national standard test but do not fuel it as
> per the instructions in it – refuel it according to whatever makes sense
> for what you are doing.
>
>
>
> Regards
>
> Crispin
>
>
>
>
>
>
>
> Hello,
>
>
>
> Happy new year 2018 to everyone!
>
>
>
> I had a look at the thesis:
>
>
>
> *« Laboratory Testing Procedure*
>
> *The test procedure that was followed was according to the Water Boiling
> Test protocol (WBT) [109]. This test is a lab based test and provides for
> repeatable and low cost testing of biomass cookstoves. Because of its
> repeatable nature, it is an excellent test to determine the effect of
> certain design changes throughout the development process. »*
>
>
>
> *« It should be noted that WBT results presented here do not necessarily
> represent the channel stove’s actual performance in the field, but are only
> accurate for comparing alternative designs tested in this particular lab
> setting. This disparity between WBT results and field use has been clearly
> documented by several previous authors [99–101]. Despite the limitations of
> the WBT in predicting actual performance, it is useful in selecting the
> most promising products for field trials, and thus we have employed it in
> this study [109]. »*
>
>
>
> Sigh.
>
>
>
> Haven’t we said so many times that the WBT should not be used to select
> stoves?
>
> Like some greenhouse gas emissions, some papers, handbooks, and toolkits
> about stove testing have long-lasting harmful effects.
>
>
>
> Best,
>
>
>
> Xavier
>
>
>
>
>
> *De :* Stoves [mailto:stoves-bounces at lists.bioenergylists.org
> <stoves-bounces at lists.bioenergylists.org>] *De la part de* Tom Miles
> *Envoyé :* lundi 1 janvier 2018 21:30
> *À :* 'Discussion of biomass cooking stoves'
> *Objet :* [Stoves] Balancing Technical and User Objectives
>
>
>
> A Brigham Young Unversity thesis exemplifies a relevant topic of,”
>  Balancing Technical and User Objectives in the Design of Improved Biomass
> Cookstoves for Developing Regions of the World”
>
> By Kendall Steven Thacker, Brigham Young University
>
>
>
> “Over the past decade a large amount of research has been dedicated in
> academic literature to improving the technical capabilities of improved
> cookstoves; primarily the performance efﬁciency and reduction of emissions.
> Unfortunately, as published literature has highlighted, the trade-offs that
> result from placing such a concentrated emphasis on these technical
> objectives is that improved cookstoves lack the same level of usability as
> traditional cookstoves. Thus, users often return to using their traditional
> stoves and the potential impact of the improved cookstoves is never fully
> realized. In order for improved cookstoves to have greater impact, there
> must be betterbalancebetweenthetwocompetingdesignobjectivesoftechnicalcapabilitiesandusability.
> This research explores the challenges and beneﬁts associated with achieving
> the appropriate balance, and provides guidance on how to more effectively
> achieve this. A list of the most common customer needs from around the
> world is provided for cookstoves. Interestingly, there are needs that are
> common to all cookstove users (global needs), and needs that apply to only
> a subset of users (local needs). Due to the diversity of such needs, there
> are many unique challenges that come with trying to satisfy these in the
> design process. A design methodology is presented that accounts for these
> challenges and helps balance the competing design objectives. This
> methodology is demonstrated through the modiﬁcation of a traditional
> cookstove used in the Tambogrande region of Peru. This modiﬁcation includes
> an inexpensive set of pot skirts that integrates directly with the
> traditional stove. These pot skirts allow for varying sizes and number of
> pots, and the use of traditional fuels. Laboratory testing, using the Water
> Boiling Test (WBT), identiﬁed the skirts’ technical improvements: 41.7%
> increased thermal efﬁciency, 32.7% decreased fuel consumption, 28.8%
> decreased time to boil. Field testing was performed to determine the pot
> skirts acceptance and compatibility with the traditional cookstoves, with
> over 75% of the participants recognizing some type of beneﬁt. Although the
> technical improvements of these pot skirts are less than other cookstoves
> on the market, the higher levels of usability are likely to lead to a more
> positive enduser reaction, which could potentially lead to higher rates of
> adoption and impact. Though this research is primarily focused on the
> application of improved cookstoves, the need for more balance between
> technical and user objectives is applicable to nearly all products being
> designed for the developing world.”
>
> https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?
> article=7301&context=etd
> <https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fscholarsarchive.byu.edu%2Fcgi%2Fviewcontent.cgi%3Farticle%3D7301%26context%3Detd&data=02%7C01%7C%7Cdb6473164177402243ef08d5522b31f5%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636505267829078461&sdata=mCR99mSBAgjcwupLcx%2BS%2FgtarpJ1hnfiV0ABphdq%2FX8%3D&reserved=0>
>
>
>
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