safety & health
Number of Dishes / Pan sizeWe now turn to the size of pans. Surveys seem to be the most popular method for obtaining this information. Table 1 is the result of a survey of seventy households in Southern Karnataka conducted by the Karnataka State Council of Science and Technology and reported in Mukunda et al.(1988). Most of these were flat bottomed aluminium vessels. The table shows that 73% of pans used lie in the range of 19 to 25 cm.
Bussmann (1988) assembled similar information from different sources about Niger in Sahel and it is reproduced in Table 2. In Niger the pans are standardized according to nine sizes. Pan diameters are found to be within 3 mm of the nominal values. This is typical for products from the informal sector using the technology of sand mould aluminium casting using the French cast iron pans as the mould.
The table shows that pan sizes 2, 3, and 4 account for 82% of the daily use in Niger.
Work done in the city of Kigali on the basis of surveys conducted in local markets showed that there are in all 31 pan sizes produced by three different manufacturers. This information from Visser (1985) is reported in Table 3. The market survey also showed that 68% of the demand was for pans in the size range 20 to 27.5cm.
This extensive information is presented here to reconcile it with the experimental results presented, on other pages on this website, that pan size has a strong influence over the efficiency of a stove. The experiments suggest that every pan requires a different design. Such a blind adoption of the principle is equivalent to the tailor made apparel of yester year and thus will put the stove out of reach of many users with limited financial means. The information we have assembled above from diverse places shows that we can borrow the rule of small, medium and large from the apparel industry for stoves as well. This will inevitably mean a slight sacrifice in efficiency, but the expectation is that loss in efficiency will be adequately compensated by the reduction in cost of the product. At the moment we cannot do any better since detailed quantitative information about these aspects is unavailable and there is no reason to believe that the experience of the apparel industry is not valid for the stove industry.