Thanks AR. The crystals do a similar job, are more easy to acquire and much cheaper than carbon. I'm not sure what type of odor carbon produces, if any, but the litter has it's own "aroma". It doesn't smell anything like kitty liter, but once it gets warm it puts out smell that you will notice. The cab was running in a smallish room so there wasn't much of a chance for the smell to dissipate, so it might not be an ordeal for most people. As it is, the smell was odd enough when "someone" was standing over the top of the cab to make them sniff it out. But it didn't smell like green!

I'm full of suggestions on topics, and answers from my short bit of experience and much reading here and elsewhere. Have a question? Just ask. :thumbsup:

Cheers