One of the key advantages of vaping vape juice over smoking is that whilst smoking creates a burning smell that tends to stick to clothing and other household items, the water vapour produces from vaping dissipates quite quickly and does not attach itself to materials.
However, it should be noted that the amount of time it takes for vapour to dissipate is highly dependant on the VG/PG ratio of the liquid being used.
The higher the VG number, the longer the vapour will linger and the more likely it is that a room will appear to be foggy.
This means that with sub-ohm 'MOD' devices that most commonly use 70VG/30PG vape juices you can expect to see a room get quite cloudy particularly if there is no direct airflow in the room. Whilst the nature of these higher VG juices does leave a room foggy, there is no long lasting smell such as with cigarettes.
With more discrete 'POD' type devices that tend to have a 50VG/50PG composition, vapour dissipates quickly and does not leave a lingering smell whatsoever.