Dear Frank >Measurement one: What you get with a long continuous run is a good representation of >emissions during the run. You do not get this with short runs.
I agree it is not the same. What we are finding is that emissions vary greatly during the test and that a long test with careful operation (including refuelling) tells you nothing in 24 hours that you can't get in 6. >Measurement two: But, as you say, the start and end of the runs are also important. >As that happens in a short span of time we need many Start / Stop events so to get an average. Averages are good for reducing the variation between readings in identical tests. As James Robinson points out, if you do a test once and record it, then do it again and get the same result, what is the point of repeating the test again? Why not do something else and get a different, meaningful measurement. That is at the core of a heterogeneous test. We need a performance curve, not a multiple repetition of one thing. When you test a car for mileage you vary the tasks (city and highway) to get a picture of overall performance. You don't drive the city route three times and average them. >We need to not try to be careful (that doesn't happen the real world) but we need to stir the fuel when adding and try to get the maximum emissions possible the stove can produce. Hmm....well that is an experiment that one could try, but it would not appear on the recommended operations list for some stoves. Some stoves are refuelled by adding it to the hopper. Now you see that there are actually three things involved: fuel+stove+method of operation. We have shown that there are savings possible of 25% on fuel and 80% on emissions simply by changing the way the stove is operated. Any international test protocol that fixes the method of operation dooms the populace to only having stove that work well using that test method. Imagine if that happened before the development of pellet stoves! Pellet stoves would never have been allowed because you can't put 4 inch oak into them! >I suggest, designing a stove -fuel combination that produces the lowest maximum emission possible (along with efficiency -measure three) should be the goal when comparing stoves. Agreed, as will many others. >After reading the rest I see we agree with each other. But I also want to add the importance of the fuel type and characteristics can not be ignored. Agreed again. In combination, they are part of what happens. Start Runs (emission) Long runs (emission) Ending (emission) Thermal efficiency Fuel characteristic range. My list would be: Starting emissions and efficiency Running emissions and efficiency High power emissions and efficiency Refuelling emissions and efficiency Low power emissions and efficiency Dying fire emissions and efficiency Not terribly different. Regards Crispin _______________________________________________ Stoves mailing list to Send a Message to the list, use the email address Stoves mailing list to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org for more Biomass Cooking Stoves, News and Information see our web site: http://www.bioenergylists.org/ [email protected] http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
