[Stoves] Air quality and stoves in Ulaanbaatar - qz.com article

[Nikhil Desai]

Crispin:

I must correct you on your abuse of the phrase “PM 2.5” and conflate it with any “smoke” and with “pollution”.

PM 2.5 may or may not be “smoke”. 

Smoke may or may not be PM2.5. 

Just what PM2.5 is “pollution” depends on chemical speciation, coincident pollution (ozone, CO, say), exposure profiles, and health condition. 

Air quality is a complex science. Reducing air quality to smoke or PM2.5 is stupidity or conspiracy. 

One more thing about alternatives to direct use of coal for home heating in Ulaanbaatar - apartments or tenements with central heating plants. I don’t know if the apartment share of dwellings has increased in the 20 years since I went there (July, thankfully). Housing finance can change household energy and combustion technology markets very rapidly. 

I am guessing that apartments and outsourcing of cooking did far, far more to shift markets for cooking energy fuels or technologies than all stove programs combined. 

As these trends go, biomass household cooking will be left for chronically poor and elderly users. Not a market we can get too excited about, whatever the smoke. Or PM2.5. Or pollution. 

Nikhil Desai
Skype: nikhildesai888

> On Mar 11, 2019, at 2:54 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:
> 
> Dear Friends of Warmth
> 
> Staying alive in Mongolia is a struggle. This article<https://qz.com/1557026/mongolias-air-pollution-crisis-is-the-future-of-our-cities/> by Annabelle Timsat published yesterday on what it is like to raise children in Ulaanbaatar.
> 
> There is something very interesting about the frontpiece photo. You can see in the lower portion the homes and their individual little chimneys. That is smoke, meaning mostly PM2.5 and a little water vapour.
> 
> [cid:image002.jpg at 01D4D81A.57DC9450]
> Above it is the inversion layer through which you cannot see the surrounding mountains. Above that you can see the steam rising from the cooling towers of power station #4. Notice there is on chimney visible above the smog. It rises 50 m above the inversion layer (which gives you scale for the rest of the photo).  What is coming out of the stack is also mostly water vapour but some smoke as well.  Then notice that the steam (about 95%) and smoke (maybe 5% of what you see) from the power plant remains above the inversion layer which is capped at 200m.
> 
> This is the result of good air quality management planning. Virtually nothing from the power station enters the city's airshed. The stack is 250m high.  The pollution you see has three contributors. It looks as if the photo was taken at dawn.  The smog is ice fog, domestic coal smoke from homes, and vehicle emissions (mostly water vapour but some PM). The homes are emitting smoke because all the fires have just been refueled after the family wakes. The smoke from homes is episodic, not continuous so the photo captures it at its worse.
> 
> Prof Lodoysamba says that there is an inversion in the city every night, and even during the day if the temperature stays below -30°C.
> 
> In the medium term, dealing with this air quality problem requires reducing stove emissions. There is not yet enough electricity available to heat all these homes and there is no gas available yet. Switching to wood is not viable due to the amount needed.  The domestic wood stoves are typically better than the hydronic heaters used in the USA, but that is not saying too much - wood requires more time and attention which at night is an inconvenience. There is quite a lot of opportunity to combine more modern home designs and high-mass, wood-fired heating systems such as those promoted by the MHA<https://www.mha-net.org/>.
> 
> This challenge is for stove designers. Perhaps you have ideas that can help.
> 
> Regards
> Crispin