Billy1111 said:

mycomonsters is solid peeps =)

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blackout said:

Nice work.
A few questions.
How have you figured the 6.1c and 6.7c figures?

A: weighing of each propane tank prior to and after each cycle, dividing the propane usage by the jars in the cooker.

The mirro does 32 jars in 140 min while the AA does 60 in 185min. so I figure it to be 4.375min per jar vs 3.083min per jar. Then the mirro should cost 142% more per jar than a AA. Or am I missing something?

A: The more product in the cooker/sterilizer.. makes for more time to heat along with sheer mass of the cooker. the 11 and 22 use same amount of water but the little one is not capable of holding the same amount of jars.. thus the difference in fuel usage per jar.

Were they all filled with the same amount of water?

A: the mirros had 8 pints each, the aa uses only 2 pints of water



Have you any theory on the extra 45mins for the AA? while 16 extra jars in the big mirro only needs 5mins more?

A: The water levels in the mirro cookers were identical.. the added water compared to the aa.. acts like a flywheel per say.. more medium to transfer heat.

The AA is a larger unit so heat loss to the surroundings will be more, but its surface to jar ratio will be less than the 2 mirros so I would think it would be more efficient (i.e. would take less than 5mins more per extra 16 jars), unless you have poor sealing.
A: The aa is more efficient likely due to the fact that it is a sterilizer and not a cooker, it does not vent steam throughout the cycle as the mirro cookers do. Also, the aa is so large it blocks off the heat from escaping past the sides, heat was directed downward rather than up the sides, making the ground near it unbearable regarding temperature.


Or were you using different power settings for each? the AA will have most heat loss so will require more power which may explain the 6.7/6.1c difference yet I still think it should be a bigger difference.

A: Throttles for the cookers were all adjusted differently due to demand for heat. Once steam flow was established.. I tried to make them chatter as evenly as possible(venting similar amounts of steam) The little mirro barely had a flame under it.. the aa has to be watched closely and as the product heats up inside, the throttle has to be lessened.


The most efficient operation is to heat with the highest available power, then lower it so it is just ticking along at 15psi with no steam venting at all. You can also insulate the boiler, heating outside will have a very large heat loss compared to indoors. I operate and ambient cooled still and there is a huge difference in heat loss in/outside

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