Humidity & Physics

[HowardWCampbell]

Small tent has 60% humidity at 8 am when my girl wakes up.

Big tent has 48% humidity. Household humidity is at 44%. During the day, with light on, the small tent hovers at 46% - 47%, with tent closed, and 45% - 46% with tent open.

What am I not understanding about physics and humidity? Why does this happen overnight?

Tonight, I’ll leave vent out of big tent, and off.

[HowardWCampbell]

Warmer air cooling creates condensation.
Got it.

[Toker1]

That depends on the due point temperatures.
Here is why: Warm air has the ability to hold more water than cooler air does. We view RH as a %. When the air warms up, the ability to hold water increases...if there the water in the air is constant for a room then the RH will decrease with increasing temperatures and RH will increase with decreasing temperatures.
The reason for the difference you are seeing is the temperature is fluctuating faster than water is being added or removed from the air.

[9fingerleafs]

Toker said it well. The same thing goes for temperature, raise or lower the rh and the temp will change too. I think you are wondering why does the humidity increases by its own? This happens because the plants are constantly evaporating water tru the leaves to maintain temperature so at morning when they wake up there is moisture buildup in the tent.

[SinsemillaScientist]

Not to mention plants transpire during dark periods releasing moisture and trapping co2. Increases humidity.

[Toker1]

Great point!