Why You See Your Breath on a Cold Winter Night
Condensation can occur if moist, warm air mixes with cold, dry air.
Temp RH SVP VP
Air
0oC 20% 6 mb 1 mb
¥ (clear)
Breath
36oC 80% 63 mb 55 mb
¥ (clear)
50-50
18oC 140% 20 mb 28 mb (cloud)
90-10
4oC 90% 8 mb 6 mb
¥ (clear)
The 50-50 mix condenses into a cloud that quickly evaporates as your exhalation is diluted furtherAhrens Fig. 4.5
Breath
Air
50-50
90-10