Yeah, there is 'some' odor when you exhale the vapors, at least from my Volcano. My wife doesn't use cannabis, and is very sensitive to the odor of it. Burning it was a sore spot.

After getting my Volcano, she can sit in the room with me, and not be annoyed. She does report brief odors, but nothing near what she notices from bong smoke, for instance. If you were in a closed room, It would be very unlikely that anyone outside of that room would detect the vapors. Canines might, but certainly no normal humans.