[Stoves] Difficulties about standards and goals .. was...Re: Guatemala meeting about tests and standards

Wed Nov 26 19:53:27 CST 2014

Dear Paul and Dean

PA> We know that the work is not easy.   And most of us (including guys like me) have chosen to not be on those working groups, although we are aware that individuals can still join them.

PA> We who are not on the committees hear of the current status of standards, and attempt to present our stoves in light of those standards.  

The Standard development process is not open to individuals. Within a nation, the Technical Committee members are representatives of organisations. Below them there are one or more Working Groups which individuals can join. At the ISO level the TC’s are national standards organisations and members of Working Groups are members of national Technical Committees or sponsored by them as experts, but first have to become TC members. 

A standard does not have a ‘current status’ until something is published for comment. There are several steps to follow that stage. It runs through various draft stages, sometimes a portion at a time.

PA>We simply do not know, but from my perspective (based on my past experiences at numerous Stove Camps and ETHOS meetings and elsewhere), the Tiers system and the WBT have been perceived as "close to acceptance."  

This is simply a misunderstanding. The WBT is not acceptable to all sorts of people and they have already decided, often years ago, not to use it because it doesn’t do what they need done. Tiers are usually associated with energy efficiency rating systems, not regulation of products. Combining them is rare. National usually rule that a product is or is not compliant with the required standard. The ‘tier’ is Pass/Fail.  Products are not rated as ‘half-safe’.  Voluntary labelling is sometimes applied by the manufacturer. 

PA> The third statement refers to the evident medical fact that even the current definition of Tier 4 stoves will not accomplish the desired health impacts, which can be attained by LPG and electric stoves.

The statement is uninformed by the performance of current products, not to mention future developments. I already reported the achievements in Ulaanbaatar created by changing only about ½ the domestic combustors. The improvement in air quality is 45% in two years (PM2.5).  This has been achieved while still burning unprocessed coal – something never before accomplished. Two things are evidenced by this: it is not necessary to change from solid fuels to liquid and gas fuels to generate an enormous positive impact, and solid fuels can be burned extremely cleanly if the investment needed is made in the products. It happens that in Mongolia the investment in product development has been nearly nil but it was still pretty easy to accomplish. It could have been done with much less money but time was tight and they chose to spend as they did. 

DS>The Tier 4 called "Indoor Emissions for PM" is close to the WHO guideline so biomass stoves that meet that criteria are seen as protecting health by the WHO.That's for unvented stoves.

DS>The Tier 4 Indoor Emissions for PM metric is "less than 2mg/minute". The WHO guideline for stoves with chimneys is much higher (7mg/minute) so the WHO guideline is a lot more lenient and many biomass stoves meet this level of performance (TLUDs, fan stoves, etc.).

Dean posted that in reply. I think it is worth exploring the topic a little.

The WHO exposure guidelines refer to what a person ‘gets to breathe’. What a stove puts out obviously affects what is in the room (assuming you don’t install a chimney stove). However it should be clearly kept in mind that you cannot test a stove and tell someone what their exposure will be.  Indoor air quality is determined in either a real room or a modelled one. What people are exposed to in the field, which is what really matters, is determined by the local architecture.  In short, one cannot measure the emissions of a stove and predict human exposure unless the local context is known. The metric ‘less than 2 mg/minute’ is an odd one because if a stove is more powerful, it would emit more at a constant combustion performance. The EPA also has a strange metric like that, where emissions are limited ‘per installation’ regardless of size. 

Further, the local context can strongly affect the exposure. We found that in Central Java the exposure to the emissions in the room was perhaps 20% of the theoretical exposure because people are not in the room a great deal of the time. This shows once again that a stove tested and rated ‘out of context’ has an unknown impact.

Regards

Crispin

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