In a past blog, on treating manure with SuperCal SO4 , I made some assumptions and statements on heating air with high rates of ammonia that were not quite accurate.
Bill Walker with CPS, pointed this out to me a number of months ago. Dan Gabig wrote me recently with similar comments: "Now as to the increase in propane usage associated with the higher specific heat of ammonia gas versus ambient air. Craig forgets to factor in that his example barn had 125 PARTS PER MILLION of ammonia. Hence one would only have a mixed specific heat of 1.55 times the ammonia content of only 125 divided by 1,000,000 and .885 times 999,875 [1,000,000 - 125] for the remainder of the barn air. So the increase in propane usage as a result of the higher specific heat associated with the tiny percentage of ammonia instead of lower specific heat for the non-ammonical air (e.g. nitrogen and oxygen) is incredibly little!!!!! Definitely not a economic consideration for litter treatments."
I admit Bill and Dan are right. It is not that your heating the ammonia in the air that is the big savings. However there is big cost savings associated with exhaust fans not running as much, not venting heated air and reheating fresh air. Add that to the fact the increase in bird health, rate of gain and lower death loss from less ammonia in the air, and the costs and savings start adding up.
I was also wrong the the cost of PLT, it $398 per ton not per 50 lb bag. Even at that price SuperCal SO4 cost less than half of what PLT does! Still a huge savings.
I will stand by SuperCal SO4 as a great, inexpensive poultry litter treatment. We currently have it in laboratory testing and the tests are backing us up. I look forward to publishing that information latter this fall. If your a farmer and want to test it for yourself, give us a call, we would love your feedback.
Again, I just didn't have it quite right, and I appreciate Bill and Dan's attention to detail and willingness to let me know that. Thanks for setting me strait!