[Stoves] Progress in Kyrgyzstan

Sat Mar 4 19:36:09 CST 2017

Dear Paul

Good questions.

We ask a lot of questions in the follow up. One is what people who have the stoves would be willing to pay for them. In all cases the offer was one quarter to one third higher than the retail cost, with the higher end stoves.

The retail price for small quantities (if I recall these correctly) are
Model 1 $50?
Model 2 ‎$90
Model 2.5 $120 probably
Model 4 $140
Model 5 $280

Something like that. They are all cheaper in Tajikistan by about $20.

I expect the costs to drop. Those quantities were small. The plan is to order them in 100-200 stove lots. This is within the capabilities of local producers, just.

One reason the current cost is a little high is that we insisted that all parts be cut by one company so there were no fabrication errors. Multiple producers were involved, but all parts were cut by a CNC plasma cutter. I assembled one unit from the parts to approved them. Then that drawing was used for all the subsequent production.

The current activity is making a dozen Model 2.5's to get a firm price.

Regards
Crispin

Crispin,

Thanks for that great report.   Congratualtions!!!!   Great to read of progress!!

Please tell us about the cost of the stove models.   And can the people afford them?   And prospects for have sufficient production in the near future.

Paul

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

On 3/4/2017 1:15 AM, Crispin Pemberton-Pigott wrote:

Dear Friends

An update is in order from the field in Kyrgyzstan to let you know how the new stoves are being accepted.

A quick review:

We are testing heating stoves with cooking functions (mostly). Some people cook with electricity or gas, everyone heats water on whatever stove surface is available.

We installed 4 models of stoves in a total of 51 homes. In the areas primarily burning dung we installed Models 1 and 2 which are brick-lined box stoves. The Model 1 is a chimney heater, meaning it generates heat that it puts into the chimney which serves as the heat exchanger, or into a brick wall as a 'heating wall' which are very common.

Model 2 is the same, one brick longer and has a heat exchanger, operating like a conventional space heating stove in North America. The fuels are dung, wood, cotton stalks, and combinations, often dung co-fired with wood. In some cases, particularly when it is extremely cold, they co-fire coal with wood or use coal alone.

The Model 4 has been previously described. It is a cross-draft coal gasifier with extremely low emissions of PM and CO. It uses coal between 16 and 25mm. This was installed in regions where coal is predominantly used, or in the case of Naryn, where all fuels are used.

The Model 5 is a low pressure boiler. It was installed in homes where there is a central water heating system with water circulation powered by a pump or naturally by a thermosiphon.

In those homes in the high mountain region of Naryn, the Model 1 and half the Model 2 were rejected for lack of heat. The home temperature was lower than with the traditional stove. The fuel consumption and emissions, cooking performance etc was not of interest because the homes were too large and outside it was too cold to heat the home adequately. Half the Model 2 owners kept on. One man was happy with it from the beginning because his place was smaller and it was working fine for him. There is appreciation for the fact that the stove will burn well with only dung instead of having to co-fire it with wood which is more expensive.

The Model 4 recipients were universal in their praise of the stove. It is faster cooking, has controllable heat, uses far less fuel, and uses a cheaper size of fuel than the regular stoves. Coal of 80mm is more expensive as everyone wants it. The 16-25 size is 1/3 cheaper. Because the stove needs so much less of it, the overall saving is large.

The major compliments were:

It always has hot water as the stove is never going out.

It heats for 10 or more hours without attention.

There is no longer any smoke in the house.

There is no smoke from the chimney.

It uses 1/10th of the wood needed to light the traditional stove.

It lights quickly (ignition to cooking time).

It heats two rooms whereas before the stove only heated one.

The temperature in the house is higher than it was before, even though two rooms are being heated.

The Model 5 recipients were of two kinds - those whose house was too big and those whose house was not. Correctly selected, there is adequate heating using normal operation. In homes where it is undersized, people found that it can be 'pushed' by opening the ash drawer a little which drives the fire much faster. Earlier testing shoed the increase in water heating power was 50% but we advised against using it in that manner.  It is clear that we need a larger version because except for heating power, it was also highly appreciated.

The compliments were about the same as for the Model 4:

There is no longer any smoke in the home.

It uses much less fuel.

It runs for a very long time.

We wish we could also cook on it (or heat water).

We now have the option of putting a heat exchanger into the Model 4 or a cooking function onto the Model 5.

The stories coming back from the field about the Model 4 are going to be legendary. In one village of 150 homes, the project vehicle was stopped 30 times by people demanding to know where they could get such a stove. One woman wanted 6. Another wanted 11 for her entire extended family.

In a village where there were both Model 2's and 4's, all the Model 2 owners (burning biomass) wanted to switch to the coal-burning Model 4's even though they would have to buy fuel. It simply transformed the way the family lived: warmer, cleaner and far more convenient.

In a village with 400 homes, 4 of which had Model 4's, the chief told me he needed 130 immediately for all social passport families. They were saving so much expense it has the effect of more than doubling the government grant. The homes were obviously warmer in spite of the reduction in fuel consumption.

Calculating three different ways, we arrived at the conclusion that the stoves produce 40% more heat using 40% less coal. While they could have saved 66% they chose to be warmer.

Asking how many times they light the stove, some replied, "Never."  Since it was installed it has never gone out. They simply refill the hopper every 10-12 hours. Because the stove requires that the fuel be made smaller than 30mm people were asked about it. Was it drudgery?  They replied that to make two buckets a day of coal to size was far preferred over burning 5 buckets a day.

In several homes we found that the heating stove was not capable of cooking. It would heat but not boil water. People resort to using an electric kettle for hot water and some cook on an electric hot plate placed on top of the stove, even when it is running!

All that has ended. Because the stove runs all the time at a constant, regulated heating power, kettles and buckets of water placed on the stove are always hot. This is considered a major social upgrade.

Something that surprised us was the number of times that a cat appeared in the photos, usually under a stove. The leg length is important for cooking height and fitting into the space under the heating wall (many are bridge-like mounted over the stove). So leg length is also important for making sure the cat can get into its favourite place.

As a result of the rejection of the Model 2's in the really cold regions (-35 C at night) we decided to create a much larger dung burner. This is dubbed the Model 2.5 and is available for download on my website in the Library under Stoves/Kyrgyzstan/Model KG2.5. This is about 80% larger and has two new features. It has an upwards sloping flame tube at a raise end on the heat exchanger both to create enough heat exchanger surface and to accommodate the flame tube.  The tube points into the far left corner which is protected by three sacrificial metal plates welded inside the body. They will evaporate first so the body will last longer.

The layout is the same as for the Model 2 except it is wider. The heat exchanger is longer and taller. The efficiency is about 85% and it will work very well using dung along. The emissions are low.

As a coal burner, it gets the same treatment as the Model 2: the grate has two positions so the grate tilts towards the fire. The fire is always ignited and operated under the cooking station, not by the door. As the coal burns it falls from the door-side down towards the fire, working mostly as a crossdraft gasifier. The result is a very long burn (9 hours) using 10 kg. Burning dung, it can hold 5 kg of low density fuel and burns for about 3.5 hours with half an hour in reserve to burn the remaining char. With both fuels, this is far longer a burn time than the traditional stove.

Cooking power is greatly enhanced but we don't know by home much. Boiling water takes 3 minutes per litre which is apparently very quick, according to them. Good. The raised heat exchanger can accommodate a 20 litre bucket of water for heating. The cooking hole can accommodate a 30 litre wok.

Fortunately for us, the organisation Fresh Air in the Netherlands is monitoring the IAQ before and after the stoves are changed, including monitoring similar homes nearby. The smoke encountered indoors is appalling, running up to 6000 µg/m3. That is measured personal exposure, not measured in the home. We will get the results of after intervention in a few days. Apparently it looks good.

A similar pilot is taking place in Tajikistan as well but without the IAQ monitoring. They are using Models 1-4 including the Model 3 which is a TLUD for heating social buildings (schools etc) during the day only.

All the stoves are free-to-air with the latest drawings appearing either in the Kyrgyzstan or Tajikistan folders. There is an elliptical hole calculator in the Model 2.5 folder for workout out the angle of the cut on the flame tube where it intersects  the central divider. This will help constructors who wish to change the offset up or to the side.

Regards

Crispin

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