"JNJ" wrote in message
...
Ok, I give. The byproducts of burning natural gas include carbon
monoxide,
PCBs, particulates, and so forth.

Back to chemistry class. Natural gas is mostly methane CH4 Burned
properly you get H2O and CO2 . The modern ones include CO detectors that
shut it down if the CO gets going. Under normal operation it is not a
problem.


Yet, we have these nifty gas fireplaces
that have no vents. As the stores that sell them will quickly tell you --
no vents are needed, there's no exhaust.

Huh? It's a simple reaction -- the byproducts must go somewhere. So
what's
the deal with these things? Are they just that efficient? Is the exhaust
just so minute that it's not worth noticing? How do these things work?

James